DartPro 32 Knowledge Vault:

QUESTIONS:

General Questions:

1. Where can I buy DART DartPro 32?
2. Is there a demo version of the software? Does the demo have any restrictions on its use?
3. Which operating system(s) can be used with DART DartPro 32?
4. I'm using Windows 3.1 (3.x). Can I use DartPro 32?
5. I'm using Windows 95. How do I install the software?
6. I'm using Windows 98. How do I install the software?
7. I'm using Windows NT 4.0 Server/Workstation. How do I install the software?
8. I'm using Windows 2000. How do I install the software?
9. What are the computer requirements for using DartPro 32?
10. Do I have to have a CD-R or CD-RW drive to run the DartPro 32?
11. Is there any other special hardware or equipment that's needed to take full advantage of DartPro 32?
12. Is there any other special software that's needed to take full advantage of DartPro 32?
13. I'm not sure how to begin. Is there any kind of tutorial or method for helping me get started?
14. How long will it take to restore my audio and finish a CD?
15. Can I play or record MIDI (*.mid) files with DartPro 32?
16. Can I play or record MPEG3 (*.mp3) files with DartPro 32?
17. Can I speed up or slow down an audio track?
18. What is the difference between the unlockable version and the boxed version of DartPro 32?
19. What are the differences between DartPro 32 and DartPro 98?
    

    Downloading, Installing or Unlocking a DartPro 32 Demo:

20. How do I download the demo version of DartPro 32?
21. What are the restrictions of the demo version of DartPro 32?
22. What do I do after downloading the DartPro 32 demo file?
23. How do I 'unzip' and Install the demo of DartPro 32?
24. What does "Unlock" mean?
25. How do I unlock (purchase) the demo to make it a full version of DartPro 32?
26. How much does it cost to purchase a copy of DartPro 32?
27. How do I upgrade from DartPro 32 to DartPro 98?
28. If I delete my copy of DartPro 32, or buy a new system, how do I get a new unlock code?
    

    Recording Audio with DartPro 32:

29. How do I connect my turntable or stereo system to my PC's soundcard?
30. How do I control, or adjust, my soundcard's input signal level?
31. Can I record audio directly to MP3 format?
32. How do I start recording a new file?
33. What parameters should I set when recording a new file?
34. What do I do in the record window once I've set my record parameters?
35. How long of an audio file can I record?
36. Can I cut longer recordings into shorter pieces?
37. How do I get, or 'read', tracks from my audio CDs?
    

    Editing Audio with DartPro 32:

38. What's my first step in restoring audio with DartPro 32?
39. How do I use the editing tools in DartPro 32?
40. What is a 'block'?
41. How do I select a block of audio to work on?
42. What is a "Source" file? How do I create one?
43. What is a "Destination" file? How do I create one?
    

    File Menu Items:

44. New - What does this do?
45. Open - What does this do?
46. Save As - What does this do?
47. Rename - What does this do?
48. Delete - What does this do?
49. Close - What does this do?
50. Open Audio Tree - What does this do?
51. Create undo file - What does this do?
52. Open undo file - What does this do?
53. RAW to WAV - What does this do?
54. WAV to RAW - What does this do?
55. File info - What does this do?
56. Register - What does this do?
57. Exit - What does this do?
    

    Edit Menu Items:

58. Undo - What will "Undo last edit" do to my audio?
59. Cut - How can I delete, or cut, selected areas from my audio?
60. Copy - How can I copy a selected area from my audio?
61. Paste insert - How do I use this paste option with my selected block of audio?
62. Paste over - How do I use this paste option with my selected block of audio?
63. Paste fill - How do I use this paste option with my selected block of audio?
64. Save paste buffer - How do I use this paste option with my selected block of audio?
65. Go To - How can I go to a selected areas within my audio file?
66. Select local block - What does this do?
67. Select modified area - What does this do?
68. Find bits - What does this do?
69. Set bits mode - What does this do?
70. Clear bits mode - What does this do?
71. Normal mode - What does this do?
72. Set bits in selected block - What does this do?
73. Clear bits in selected block - What does this do?
74. Toggle bits in selected block - What does this do?
75. Set/Remove markers - What does this do?
76. Set/Remove click markers - What does this do?
77. Set/Remove frame - What does this do?
    

    Group Menu Items:

78. What is 'grouping'? Why would I use it?
79. How does grouping work?
    

    Toolbox Menu Items:

80. What is "Scale"? What does it do and how does it work?
81. What is "Maximize"? What does it do and how does it work?
82. What is "Mute"? What does it do and how does it work?
83. What is "Reverse"? What does it do and how does it work?
84. What is "Compare"? What does it do and how does it work?
85. What is "Mix"? What does it do and how does it work?
86. What is "Split"? What does it do and how does it work?
87. What is "Unite"? What does it do and how does it work?
88. What is "Mono"? What does it do and how does it work?
89. What is "Stereo"? What does it do and how does it work?
90. What is "Equalize"? What does it do and how does it work?
91. What are the "Filter" tools? What do they do and how do they work?
92. What are the "Fade" tools? What do they do and how do they work?
93. How and when do I use Resample?
94. How and when do I use Adjust sample rate?
95. How and when do I use Trim length?
96. How and when do I use CD format?
97. How and when do I use the Find pattern function?
98. How and when do I use Spectrum or Spectral View?
    

    Restore Menu Items:

99. How and when do I use DeClick?
100. How and when do I use Retouch?
101. How and when do I use DeHiss?
102. How and when do I use NoisePrint?
103. How and when do I use DeNoise?
104. How and when do I use Duplicate?
105. How and when do I use Test?
106. How and when do I use MyFilter?
107. How and when do I use Filter Builder?
     

     Options Menu Items:

108. How should I assign my settings in the 'Setup' menu?
109. How should I assign my settings in the 'Hardware' menu?
110. How should I assign my settings in the 'Colors' menu?
     

     Making an Audio CD from a Playlist in DartPro 32:

111. What's a 'playlist'?
112. How do I use the Wave Manager to create a playlist?
113. Where do I find my files to add?
114. Can I save a playlist to work on it later?
115. How do I adjust the order of songs on the CD?
116. Can I adjust the gap time (silent section) between songs? If so, how?
117. Can I add text info, such as artist, title, etc., to my CD (CD+Text)?
118. How do I remove songs from a playlist?
119. How do the different playback modes ('Loop', 'Samp', and 'Norm') work?
120. How do I burn the audio files from my playlist to a CD?
121. What speed of CD burning should I select?
122. When should I delete my original recorded files from the hard drive?
123. When I try to use different areas of CD-Recorder 4 Basic, I'm told that feature isn't allowed. Don't I have a full version?"
     

     Troubleshooting and Problems:

124. Why do I get the message, "Unable to find known CD Recorder," when writing to a CD?
125. What is "ASPI"? Why does the program mention that there is a problem with it?
126. When trying to burn a CD, I get the message "ASPI buffer too big". What do I do?
127. Why do I get the message "Protection check failed" when starting the program?
128. When I try using "Write to CD", I get an illegal operation error. What do I do?
129. When I'm in the Read Track window, and I click on Change, the program crashes. How do I fix this problem?
130. After installing the latest update for DartPro 32, I don't have a shortcut to CD-Recorder 4 Basic in my 'Start' / 'Programs' folder. What's going on? How do I fix this?"
     

ANSWERS:

General Questions:

1. Where can I buy DART DartPro 32?

   You can purchase DART DartPro 32 at our online store, located at http://www.dartpro.com/Products/Cart.asp or by using one our many resellers. Our official resellers' link can be found at http://www.dartpro.com/products/ResellerLinks.asp.

2. Is there a demo version of the software? Does the demo have any restrictions on its use?

   There is a demo version of DartPro 32 that you can download for free. It has a few restrictions on its use, but you can run it for as long as you would like. The restrictions on the demo are:
   

   1. You can only record up to 2 minutes of audio.
   2. You are not able to write to a CD using the demo version of DartPro 32.

3. Which operating system(s) can be used with DART DartPro 32?

   DartPro 32 is designed to run under Microsoft Windows 95, 98, NT or Windows 2000. At this time, there are no plans to support any other operating systems.

4. I'm using Windows 3.1 (3.x). Can I use DartPro 32?

   No, you cannot run DartPro 32 if you use Windows 3.1 (3.x). It has been designed for, and runs only under, Windows 95, Windows 98, Windows NT 4.0, or Windows 2000.

5. I'm using Windows 95. How do I install the software?
   • To install DART DartPro 32, insert the setup CD-ROM into your drive. In Windows^tm 95, the installation procedure will launch automatically, but only if the automatic insertion feature for your CD-ROM is active.
   • To install DART DartPro 32 manually, go to the Control Panel, click on Add/Remove Programs and choose SETUP.EXE on your CD-ROM drive.
   • The DART DartPro 32 installation program will start, pausing only to ask in which directory you would like to install the program (we suggest that you use the default values) and the CD drive (or "CD installation path") where the setup CD is located.

6. I'm using Windows 98. How do I install the software?
   • To install DART DartPro 32, insert the setup CD-ROM into your drive. In Windows^tm 98, the installation procedure will launch automatically, but only if the automatic insertion feature for your CD-ROM is active.
   • To install DART DartPro 32 manually, go to the Control Panel, click on Add/Remove Programs and choose SETUP.EXE on your CD-ROM drive.
   • The DART DartPro 32 installation program will start, pausing only to ask in which directory you would like to install the program (we suggest that you use the default values) and the CD drive (or "CD installation path") where the setup CD is located.

7. I'm using Windows NT 4.0 Server/Workstation. How do I install the software?
   • To install DART DartPro 32, insert the setup CD-ROM into your drive. In Windows^tm NT, the installation procedure will launch automatically, but only if the automatic insertion feature for your CD-ROM is active.
   • To install DART DartPro 32 manually, go to the Control Panel, click on Add/Remove Programs and choose SETUP.EXE on your CD-ROM drive.
   • The DART DartPro 32 installation program will start, pausing only to ask in which directory you would like to install the program (we suggest that you use the default values) and the CD drive (or "CD installation path") where the setup CD is located.

8. I'm using Windows 2000. How do I install the software?
   • To install DART DartPro 32, insert the setup CD-ROM into your drive. In Windows^tm 2000, the installation procedure will launch automatically, but only if the automatic insertion feature for your CD-ROM is active.
   • To install DART DartPro 32 manually, go to the Control Panel, click on Add/Remove Programs and choose SETUP.EXE on your CD-ROM drive.
   • The DART DartPro 32 installation program will start, pausing only to ask in which directory you would like to install the program (we suggest that you use the default values) and the CD drive (or "CD installation path") where the setup CD is located.

9. What are the computer requirements for using DartPro 32?

   The following are really more recommendations than requirements, as the program can run (albeit much slower) on a system with less power than the one described below. However, digital audio programs can be very taxing on a system, so the better computer you use, the better the software will run. As with most things computer-related, your mileage will vary. Here's what we suggest:
   

   Recommended CPU:	200MHz or better
   System Software:	Microsoft Windows 95®, 98®, NT 4.0, and Windows 2000
   Memory:	16 MB RAM or higher
   Hard Disk Space:	1.2 GB Disk
   Sound Card:	16 Bit Windows compatible (for analog recording & MIDI rendering).
   CD-R or CD/RW:	SCSI or EIDE CD-R or CD-RW drive (for writing music CDs).

10. Do I have to have a CD-R or CD-RW drive to run the DartPro 32?

    You don't actually HAVE to have one of these to use the software. However, you'll get very little use out of the program if you can't burn CDs (that is what it's made for, after all). There are users who run DartPro 32 simply for the restoration filters (DeClick and DeHiss) and for the ability to convert MP3 files to WAV files or MID files to WAV files.

    Getting the best out of the software, though, requires a CD-R or CD-RW device.

11. Is there any other special hardware or equipment that's needed to take full advantage of DartPro 32?

    Not really. As long as you have the external gear (turntable, cassette player, microphone, etc.) and a computer with soundcard, you should be ready to go. Of course, if you have a CD-R or CD-RW drive, you'll be able to get even more out of the product.

12. Is there any other special software that's needed to take full advantage of DartPro 32?

    No. As long as you're using a supported operating system, a supported CD-R or CD-RW drive and a functioning soundcard, then you should have everything you need.

    We DO, however, recommend having a quality MP3 encoder software (since ours currently doesn't support this feature). WinAmp, Xing player, RealPlayer/Jukebox, or MusicMatch and others can do a great job for most users.

13. I'm not sure how to begin. Is there any kind of tutorial or method for helping me get started?

    We offer a few different methods to guide you on your way to restoring your audio collection, or simply making CDs from MP3 files.

    • The online Help system: Located within the program itself (under "Help" / "Contents"), the online Help system can answer many basic questions on features, use of the program, and other often used functions (such as recording audio, using the DirectX plug-ins, or writing an audio CD). This should be your first line of defense when you need to find out more about how to get the most from the software.
    • The Guided Tour: All CD versions of the DartPro 32 include a multimedia tutorial designed to show you how to use the basic functions of the program. You can play sections related to specific topics, or view the entire 20-minute presentation. NOTE: 'Unlockable' versions of DartPro 32 (including demo trial versions) don't include the Guided Tour, as the file size would be very prohibitive for most users.
    • Web-based Help: The Knowledge Vault you're reading right now is another excellent place to find answers you're searching for on DartPro 32. You can see answers by topic or simply browse and read.
    • DART Forums: We offer several online forum discussions groups for letting you exchange ideas and get help from other DART software users. You may find an answer to your question, be able to answer someone else's questions, or just find it interesting reading. Plus, the forums (like this FAQ) are open 24 hours a day, 7 days a week. DARTech support professionals, who can address many different topics, moderate the forums.

14. How long will it take to make my own finished CD?

    The best answer we can give for this is...it depends. If you simply want to make a copy of an existing audio CD, it can take anywhere from 148 min. and go down from there (148 minutes comes from a 1x read and 1x write for all tracks, with NO editing or cleaning taking place. If you'd like to do some sort of editing or cleaning to 1 or more audio tracks, this will increase the amount of time it will take. Much of this is a subjective decision. You'll simply have to decide for yourself how far you'd like to take a particular project. Some will be happy with little or no changes, some may want to do more extensive work.

15. Can I play or record MIDI (*.mid) files with DartPro 32?

    No, only our CD-Recorder and DartPro 98 products have support for MIDI (*.mid) files.

16. Can I play or record MPEG3 (*.mp3) files with DartPro 32?

    No, only our CD-Recorder and DartPro 98 products have support for MPEG3 (*.mp3) files.

17. Can I speed up or slow down an audio track?

    Depending on what you might mean by "speed up" or "slow down", we can (or can't) do this. If you want to change the pitch of a track (make a song in the key of D flat into a song into a song in B flat), then no. There is no preset tool for changing pitch in terms of semi-tones. There is also currently no method for changing the time a file takes to play without changing the pitch. This would mean that if you wanted to change a file that was 1 minute into a file that was 30 seconds, the pitch WOULD be changed to achieve this. That being said, you can actually (with practice) change the pitch of a file to a desired level, albeit with an associated change in the time (length) of the file.

18. What is the difference between the unlockable version and the boxed version of DartPro 32?

    The boxed version of DartPro 32 comes with an online guided tour and manual (on the CD) but the unlockable version does not. Also, if you delete and reinstall an unlockable version, on the same computer or a different computer, you'll have to get another (different) unlock code before it can be run again. If you are a registered user of an unlockable version you can also obtain a new unlock code via our Webpage, on the DartPro 32 Registered User Unlock Menu (more details on this are available in the next section).

19. What are the differences between DartPro 32 and DartPro 98?

    DartPro 98 is a more professional program and is used in re-mastering, professional restoration and recording studios, while DartPro 32 is more geared towards the advanced home user or audio hobbyist. You can still use DartPro 98 at home, it is all a matter of how professional you want to be in restoring, mastering, or simply recording your music. For a complete checklist of all the differences between DartPro 32 and DartPro 98, visit the Comparison Chart on our Website.

    DartPro 98 has all of the features of DartPro 32 plus:

    • A De-Hum utility
    • Direct-X support
    • Real-Time tools
    • An Unpack utility
    • MP3's and Midi conversion
    • Improved Equalizer
    • Automatic RPM Conversion
    • Smart Tools
    • Noise Print Shaping abilities
    • Many other minor improvements throughout the program

    Downloading, Installing or Unlocking a DartPro 32 Demo:

20. How do I download the demo version of DartPro 32?
    1. Go to the DartPro homepage. (On this Website under the "Home" button.)
    2. Go to the Products section by clicking on the button called "Products" on the top bar of the Webpage.
    3. Click on the Downloads button on the left part of the screen.
    4. Click on the picture of the DartPro 32 box.
    5. At the bottom of the screen, click on the "Download Now!" link.

21. What are the restrictions of the demo version of DartPro 32?

    With the Demo Version of DartPro 32, you can not write to a CD and you can only record for 2 minutes.

22. What do I do after downloading the DartPro 32 demo file?
    1. The DartPro 32 demo is in a "zipped" (*.zip) format. This means it is compressed and packaged, and to use the demo you must unzip the file first.
    2. If you do not have an unzip utility, we HIGHLY recommend that you download WinZip(r), which is free, from www.winzip.com.
    3. After downloading and installing WinZip(r), you should be able to unzip the downloaded demo file and move on to the next step, unzipping and installing the DartPro 32 demo.

23. How do I 'unzip' and install the demo of DartPro 32?
    1. Open WinZip from the start menu or via the icon on your desktop.
    2. Follow the WinZip "Wizard" instructions to unzip the DartPro 32 setup files.
    3. After unzipping DartPro 32's setup, you are ready to run the setup file that will install it.
    4. To install DartPro 32, open up the Windows Explorer. Browse to the directory folder where you unzipped the DartPro 32 setup files, and locate the file called "setup.exe."
    5. Double click on "setup.exe" and follow the onscreen instructions to install DartPro 32.
    After you finish installing, you are ready to use the DartPro 32 demo!

24. What does "Unlock" mean?

    Unlockable software means that you can download the full version of the software, but it has limitations on it. To be able to use the full version, you must unlock the software by purchasing an unlock code that is unique to your system. After purchasing the unlock code, you will be able to use the software as if you purchased the CD.

25. How do I unlock (purchase) the demo to make it a full version of DartPro 32?

    Note: The demo version of DartPro 32 has some restrictions. To lift these restrictions, you must unlock the demo by purchasing the unlock code.

    1. After downloading and installing the DartPro 32 demo, start the program and go to "Help", then to "Unlock".
    2. Write down your Code Entry and Computer ID numbers. These numbers are found in the "Help" menu under "Unlock." Make SURE that you only hit "Register Now" to close the window, as opposed to hitting "OK" (without inputting a valid unlock code) which will cause the CodeEntry number to change, thus invalidating an unlock string you are given.
    3. There are two ways of unlocking the program to make it a fully functioning version:

       A. On this Website, in the Products section.

       - Or -

       B. Contact us at:
       

       • Email: Info@DARTPro.com
         
       • Toll Free: (800) 799-1692 (In the US only), 9AM-5PM CST, Mon.-Fri.
         
       • Telephone: (952) 844-0217, 9AM-5PM CST, Mon.-Fri
         
       • Fax: (952) 844-9025
    4. To unlock your Demo on via our Website, go to the Products section.
    5. Click on the "Unlock Demos" button on the left-hand side of the page.
    6. Now, click on the DartPro 32 box graphic, and you will be taken to the "Unlock DART DartPro 32" page.
    7. After reading the application's features and system requirements, click on "Unlock Now!" at the bottom of the screen.
    8. Follow the instructions on the "Unlock DART DartPro 32" page, and use the Secure Registration and Purchase Form to purchase your unlock code.
    9. When you have finished entering your information into the form, click on the Submit button and your unlock code will be displayed on the screen.
    10. Write down your unlock code.
    11. Open the Demo version of DartPro 32.
    12. Click on "Help" in the menu bar, and select "Unlock."
    13. Now enter your new unlock code into the field labeled Unlock Code and click OK.
    
    You have now successfully unlocked DartPro 32, and you are ready to use all of the features!

26. How much does it cost to purchase a copy of DartPro 32?

    You can unlock your demo version of DartPro 32, or purchase a CD copy of DartPro 32 for the price of $99.95 (CD version price does not include standard shipping cost of $8 US / $15 Int'l).

27. How do I upgrade from DartPro 32 to DartPro 98?

    Depending on how much you paid and when you purchased DartPro 32, you may be entitled to a free, or discounted, upgrade. To upgrade from DartPro 32 to DartPro 98, you may contact us at DARTECH support, or call us at:

    (800) 799-1692 or (952) 844-0217
    You can also download the demo version of DartPro 98 and unlock it on this Website in the Products section.

28. If I delete my copy of DartPro 32 or buy a new system, how do I get a new unlock code?

    To get your new unlock code, you should go to the DART DartPro 32 Registered User Unlock Menu and follow the directions on screen. Please be sure to have your new code entry and computer ID numbers ready (they can be found in the help menu under "unlock").

    Recording Audio with DartPro 32:

29. How do I connect my turntable or stereo system to my PC's soundcard?

    The first step you'll need to take to get started recording is to set up your sound card's connection to the "outside world." There are many different types of soundcards and audio cards on the market, so the information we provide here can only give you general guidelines on how your connections will be made. Please be sure to refer to your sound device's printed or online documentation when setting up to record from its inputs. More information on soundcard troubleshooting, as well as links to many major manufacturers' Websites, can be found in the support area of our Webpage (www.dartpro.com).

    • You will need to have a stereo patch cable, sometimes called a "Y" cable.
      
    • One end of the cable will be a single 1/8" DIN connector that plugs into the computer.
      
    • The other end will need to have Dual female RCA connectors to plug into the stereo.
      
    • A typical computer soundcard has the following types of physical inputs/outputs available:
      

      * One 1/8" DIN input jack for a microphone (Mic)
      * 1/8" DIN "Line In", or similar audio (music) input jack
      * 1/8" DIN "Line Out", or similar audio output jack
      * An 1/8" DIN output (or outputs) to the speakers

    NOTE: Some soundcards now feature an additional input and/or output for digital signals (signals already converted from analog to digital). DartPro 32 can also record from these inputs, assuming that you have set up the digital output to input (and vice versa, if necessary) from your external digital device (CD player, DAT machine or stereo receiver with digital output). You must also be certain that your soundcard has selected the digital input as being "active". Check your soundcard documentation for more info on setting this up.

    Don't be too concerned if you don't see all of the possible input/output types available. The only ones that you NEED to have are the speaker output and the Line Input. Check your soundcard's documentation for more information on which jacks do which functions. Some users don't always get printed information, and in that case, your soundcard manufacturer's Website will also be a good resource for information.

    Plug the single DIN connector on the patch cable into the audio input plug-in on the computer sound card. (See Fig. 1 below.)

    (FIGURE 1)

    On the back of the stereo, choose one of the following to connect to the PC (the PC will appear as just another component to the stereo):
    

    • "Aux. Out" (for Auxiliary), or "Line Out", or "Tape2", or "Tape Out", etc.
    • Each one will be labeled as either an input or output, along with: L (Left) or R (Right) (See Fig. 1 above).
    • Pick one of these output pairs (L /R is one pair).
    • Plug the dual-end RCA connectors into the output pair (L /R).
    • Match the color coding on the cables and receptors for L & R. These are usually red and white, but can be red and black.

30. How do I control, or adjust, my soundcard's input signal level?

    After DART DartPro 32 is installed, you must set your input recording volume:

    • Double-click on the icon next to the clock that looks like a speaker. This will bring up the "Volume Control". If you don't see this control, you may also be able to access by going to "Start" / "Programs" / "Accessories" / "Multimedia" or "Entertainment" / "Volume Control"
    • Click on the "Options" menu and select "Properties."
    • Under "Properties" select "Adjust volume for" as "Recording" and make sure all of the volume controls are selected/checked on the bottom of the "Properties" dialog box. Click on "OK."
    • Now the "Recording Control" Dialog box will appear. Make sure that the proper line is selected (Usually "Line-In" or "Line"). The proper option must be selected or you will not be able to record any of the input. To select the proper line, you must make sure the correct "Select" option box is checked.
    • Use the vertical slider to adjust the input level of the source you are recording from to the proper volume. The proper volume would be when the DART DartPro 32 can record a soundfile and there is no clipping of the sound while recording.

31. Can I record audio directly to MP3 format?

    Currently, no. This version of DartPro 32 doesn't include the capability to record, or encode, audio information into the MPEG3 (MP3) format. However, there are several free players available on the Internet that CAN encode audio to MP3. Just a few examples are: WinAmp, Xing, RealJukebox, and MusicMatch.

32. How do I start recording a new file?

    NOTE: First, make sure that all of your audio connections are sound and that you've adjusted your input level on your soundcard with the directions given above. If you don't have these items taken care of first, the following steps will not yield a useable recording.

    Unless the audio you want is on an existing audio CD, you should record from your external audio source as if it were a vinyl record, cassette, or other similar analog source. If you want to get tracks from an audio CD, use the "Read Track" function described below.

    Within DartPro 32, select the "Record" button (the button that looks like a vinyl record). A dialogue box appears asking you to name the new file that will be recorded and in what hard drive and/or folder you'd like it to be saved. We HIGHLY suggest having a folder on your system that does nothing but store your audio (for example, "C:\My Audio"). Select the folder where you want to save the file, type in the name you want your new recording to have and then click on "Save".

33. What parameters should I set when recording a new file?

    You should now be in the "Record" dialogue box. You need to select the correct Sample Rate, Channel Type, and number of bits you want to use when recording your new file.
    

    • Sample Rate: We suggest that if you are recording from a record, LP, or tape that you use 22KHz Sample Rate. However if you are recording from a Mini-Disc, DAT Tape, or any high fidelity audio source you should select the 44Khz Sample Rate.
    • Channel Type: Unless you are recording from a mono source (only one channel, no left or right output), you should probably leave "Stereo" selected. Stereo means that thee are two pieces of an audio recording, one channel represents the left output, and the other channel represents the right output.
    • Number of Bits: Finally, select the number of bits (8 or 16). Selecting 8-bit gives you less quality than 16; however, it will be half the size of a 16-bit sound file.

34. What do I do in the record window once I've set my record parameters?
    1. Now that your decibel level is where you want it, and you've set your parameters, you can start recording the input. Start the audio source that you'll be recording and click the "Record" button in the record dialog box. You are now recording everything that you hear from the audio source.
    2. When the music from the source stops playing or you want to stop recording, click the Stop button in the record box and stop your audio source. Next click on "OK".

    You should now see your audio file in the file list box (in the middle portion of the file panel).

35. How long of an audio file can I record?

    You can record any file up to the amount of empty hard drive space that you have in your system. The software currently 'caps' recordings at 2GB in length. This means that you can record 2048MB of data. At 44.1kHz, 16-bit stereo (CD format for audio), this would amount to roughly 200 minutes of audio data. You can, of course, also record more tracks, but we will always have to work with whatever empty hard drive space is available.

36. Can I cut longer recordings into shorter pieces?

    Yes, just use the following 'Unpack' process to break longer recordings into smaller pieces.

    1. Select the recorded file that you want to Unpack.
    2. Go to the toolbox menu and click on "Unpack."
    3. You will then see a dialog window containing the following controls:
       • Minimum Separation time (in seconds): You have to set this according to the smallest amount of silence between your songs. It gives the program a base to begin looking for silences beyond what you specified.
       • Detection Threshold: The selection (anything between 1 and 1000) should be made in accordance with the recording level and intensity of background noise. If the threshold is too low detector may fail to localize silences between subsequent tracks; if it is too high silent parts of the recording may be mistakenly classified as breaks.
       • The "Find" button: In case there is a piece of silence at the beginning of the recording, even if it is fairly short, you can press the "Find" button situated next to the detection threshold box and the value of the threshold will be adjusted automatically.
    4. After making the necessary selections, you are ready to Unpack. Click the Process button.
    5. You should now see the Verify Cuts dialogue Box with the following items:
       • Total number of cuts proposed: This is the total number of cuts that the program suggests. NOTE: You may have some tracks that you don't want. After making the cuts you can just delete these. Sometimes it is better to accept all of the cuts (unless they are in the middle of a song) and just delete the files that you don't want in your playlist.
       • Cut No.: When you select the Cut number, you can listen to the cut by clicking Play. If you decide you do not want that cut, click Reject.
       • Change: This allows you to change the file name prefix of the tracks you are separating.
       • Playing Time (seconds): This is the length of time (seconds) in between each song.
       • Process: Click Process when you are satisfied with your cuts and selections, and the program will begin to unpack your songs.
       • Cancel: Click Cancel if you are unsatisfied with your cuts and the program will not do anything to your original sound file. After clicking cancel, you can try the Unpack utility again with a higher or lower threshold, respectively.
    6. After making all of the necessary selections and you are happy with your cuts, you can click on "Process" to unpack your sound file.

    When the Unpack utility is complete, you should see all of your tracks, separated and named with the correct track number following the file name prefix.

37. How do I get, or 'read', tracks from my audio CDs?
    1. If the audio track you want is on an existing audio CD, click on the "Read Track" button (it is the button that looks like a CD with music notes on it).
    2. Select the tracks that you want to record. If you are not sure which track you want, you can listen to the CD using the controls near the bottom of the dialogue box.
    3. After selecting the track that you want, click on the "Add" button. If all you are doing is copying the entire CD, you can click on the "Add All" button.
    4. Before you begin to copy tracks from your CD, you should select the correct read speed of your CD-ROM drive from the drop down list labeled "Read Speed."
    5. You may want to change the file name prefix if you are recording from multiple sources so you don't get confused about which file is which. To do this, click on the "change" button, type in the appropriate name, and click "OK."
    6. The program will now begin copying the CD tracks you have selected.
    7. Repeat these steps until you have all of the songs you want to record. Remember, you have a limit of seventy-four minutes when you are recording on to CDs.

    Editing Audio with DartPro 32:

38. What's my first step in restoring audio with the DartPro 32?

    This will vary, depending on how familiar you are with the program, and how the audio has to be edited to make it sound better. In some cases, you won't need to do much; other times, you may have to do quite a bit. Generally, the first step would be to listen to your recorded audio and be sure that there are no clipped sections, and to determine which, if any, of the restoration tools needs to be used. You may also decide, after listening to your newly recorded file, that you only need to do some EQ (equalization) or perform other edits than aren't necessarily concerned with our restoration filters (like Fade In or Fade Out, EQ, etc.).

39. How do I use the editing tools in DartPro 32?

    Accessing the different tools is usually accomplished by selecting the tool you want to use from the appropriate menu. These menus are described in the manual, the online Help system, and this Knowledge Vault. Some of the tools are pretty much self-explanatory, and others are more complicated. It is recommend that you use the resources above to learn more about each tool and what it does, if you're not sure. It may also be useful simply to record a "dummy" file that you can use to test out a tool and see what it does. In many cases, simply 'playing around' with a particular editing tool will instantly show you what kind of effect it will have.

40. What is a 'block'?

    A "block" is a selected area of audio. This can be as little a sample, or as big as the entire recorded file. Blocks are often used to assign areas of audio to should be deleted, or to run the restoration filters on a specific area of a file. You can select a block of audio by holding down your Control Key ("Ctrl") and left-clicking on the image of the waveform then moving your mouse. You should see the area that you are highlighting turn gray. Any gray section on the audio waveform defines a block. You can change the beginning and end point of a block after it has been selected by placing your mouse cursor over the boundary you wish to change. You should see it change to a "side-to-side" icon, which indicates that the position can be moved forward or backward. Simply left-click and drag the mouse to the new location for the boundary you're working on (either front or back).

41. How do I select a block of audio to work on?
    • To select a block of audio, hold down the control key ("Ctrl") and click the left mouse button where you want to begin selecting.
    • Without releasing the mouse button, move the mouse over the wave file until you reach the spot you want your selection to end.
    • Now, release the mouse button, and your selection will be highlighted. You can adjust your selected audio by clicking on the ends of the selection and moving the provided cursor left or right.

42. What is a "Source" file? How do I create one?

    A "Source" file is generally your original recorded audio file. When using many of the tools available in DartPro 98, you are sometimes asked to select the "Source" file. This is the file that will 'feed' the filter. In other words, if you needed to run DeClick, the source file would be the audio file that had the clicks/pops in it.

    You can select which open audio file will be your source file by clicking on the "S" in the upper left hand corner of the soundfile's window. When a file is selected is set as the "Source", the "S" will turn red.

43. What is a "Destination" file? How do I create one?

    A "Destination" file is generally the edited version of your original audio "source" file. When using many of the tools available in DartPro 98, you are sometimes asked to select the "Destination" file. This is the file that will hold the results produced by a given filter. In other words, if you needed to run DeClick, the destination file would be the audio file that had been run through the filter and had the clicks removed.

    You can select which open audio file will be your destination file by clicking on the "D" in the upper left hand corner of the soundfile's window. You can also set which file will be the destination within the filters themselves. There will be a portion of the filter that asks you to select the name of the destination file (that will be created) as well as where it should be saved. It is recommended that you select a filename that relates in some way to the original recorded "Source" file. For example:

    If your original recorded file is named "Track 1.wav", then a good name for a destination file that came from that source file would be "Track 1_DeClicked.wav". By default, the name of any destination file will be "Result.wav".

    File Menu Items:

    The File menu contains items for managing files (New, Open, Save as, Rename, Delete, and Close) or sets of files called audio trees (Open audio tree), and for exiting the program (Exit). Additionally, it provides means for performing undo operations (Create/Open Undo file), performing the soundfile format conversion (RAW to WAV, WAV to RAW), getting information about a soundfile (File info) and registering a soundfile in a DartPro 32 library of soundfiles created and handled by the Soundfile Manager (Register). For your convenience a list of recently opened files is provided at the bottom of the File menu. To open such files simply select them from the list.

44. New -- What does this do?

    When you choose this option, a new (empty) file is created.

45. Open -- What does this do?

    This option can be used to open an existing file (a soundfile or a detection file). The file select dialog, shown after choosing the Open command, allows you to inspect a list of available files, audition a soundfile prior to loading it (Play) and get basic information about a soundfile (Info). Additionally, it provides means for deleting files (Delete).

    When convenient, you can open or delete several files at once.

46. Save As -- What does this do?

    You can use this item to make a copy of the soundfile in the active window. A file select dialog will allow you to choose a name under which the soundfile will be saved.

47. Rename -- What does this do?

    You can use this item to rename a file.

48. Delete -- What does this do?

    This item can be used to delete any file from the disk. For your convenience, each time a soundfile <*.wav> is deleted the corresponding detection file <*.det> (if any) is also removed.

49. Close -- What does this do?

    Use this option to close open files. When a file is closed the corresponding window is removed from the DartPro 32's clipboard.

50. Open Audio Tree -- What does this do?

    The audio 'tree' is a family tree of a given root soundfile (i.e. the set of all soundfiles obtained by renovating the same archive recording). It allows you to review and compare different variants of processing in an easy and efficient manner.

    In order to display an audio tree:

    • Choose the Open Audio Tree option from the File menu and select the appropriate <*.sfm> database file

      Or

    • Press the AUDIO TREE button situated on the toolbar and proceed as above. Then, press the ENTER key or click on the OK button.

    A representation of a typical audio tree is shown below. It consists of the 'root' soundfile 'filename00.wav' and its derivative soundfiles - two obtained directly from the root file ('filename01.wav', 'filename04.wav') and two other ones obtained by further processing the file filename01.wav ('filename02.wav', 'filename03.wav').

    Filename00.wav

    Filename01.wav
    Filename02.wav
    Filename03.wav
    ( Filename04.wav

    The 'check' mark shown on the left hand side of the soundfile 'filename04.wav' indicates that this file is already opened, and the 'smile' sign displayed on the right side of 'filename03.wav' means that the corresponding results were considered satisfactory.

    After selecting any soundfile from an audio tree (click on the corresponding line so that it becomes highlighted), you can:

    • Play it (click on the PLAY button located inside the Audio tree dialog)
    • Get information about it (click on the INFO button)
    • Open it (click on the OPEN button)
    • Delete it (click on the DELETE button)

    If you are satisfied with the results of renovation, you can 'approve' the corresponding soundfile(s) using the 'smile' sign. The number of smile distinctions awarded to one soundfile can range from zero (no distinction) to three (a really BIG smile) and changes cyclically while you keep pressing the SMILE button.

    When you conclude your work with an audio tree, you can close the dialog or minimize it. In the second case, the updated version of the minimized audio tree will be brought back each time you choose the Open audio tree command from the File menu, or click on the AUDIO TREE button situated on the toolbar. This is especially convenient when comparing current results with the already existing ones. You will not be able to open a new audio tree unless you close the previous one (use the CLOSE button for this purpose).

51. Create Undo File -- What does this do?

    Whenever needed, you can save the current contents of an opened (active) file in an undo file. When you choose Create undo file, from the File menu, DartPro 32 creates a backup file called "filename.und" (where 'filename' is whatever you have named the file, "track01.und" for example)

    NOTICE: When opening a file, DartPro 32 neither loads its copy into memory, nor creates a backup file on the hard disk. This means that all operations on audio files, like editing or preprocessing, are performed directly on the data stored on the hard disk (otherwise, handling huge audio files would be very time- and space-consuming). We therefore recommend you create an undo file prior to any 'large scale' operation performed directly on an original soundfile - just in case something goes wrong.

52. Open Undo File -- What does this do?

    Whenever needed, you can open an existing undo file (made by Create undo file) by using the Open undo file command (after choosing this command the contents of an active file is replaced with the contents of the corresponding undo file). You can select from any existing undo file, which will have a *.und file extension ("track01.und", for example).

    NOTICE: When opening a file, DartPro 32 neither loads its copy into memory, nor creates a backup file on the hard disk. This means that all operations on audio files, like editing or preprocessing, are performed directly on the data stored on the hard disk (otherwise handling huge audio files would be very time and space consuming). We therefore recommend you create an undo file prior to any 'large scale' operation performed directly on an original soundfile - just in case something goes wrong.

53. RAW to WAV - What does this do?

    The uncompressed, and unformatted, string of bytes (for 8-bit sampling) or 'words' (for 16-bit sampling), representing the values of consecutive signal samples, is usually referred to as the 'raw' PCM audio file. When augmented with a header, containing basic information about the recording (sampling rate, sampling resolution, number of channels, number of samples) RAW files become WAV files (WAV stands for a standard Windows format called WAVE). DartPro 32 allows you to convert RAW audio files into WAV files and vice versa.

    RAW to WAV Conversion:

    Input file: *.raw ("track01.raw", for example)

    Output file: *.wav (default) - ("track01.wav", for example)

    Processing mode: global

    In order to change a raw PCM soundfile into a wave file, choose the RAW to WAV command from the File menu. A dialog will appear allowing you to select recording details, such as the sampling rate, sampling resolution and number of channels. If you import a raw soundfile from an unknown source, you may need to experiment with record settings in order to find the appropriate ones - to audition results, press the Preview button.

    Fast Format Conversion:

    If the files you want to convert from one format to another are very large (think of one hour of recording, for example), the processing times may be excessive and, in fact, unnecessarily long. You should be aware that all the system is doing after adding the header to the input file (RAW to WAV), or depriving it of the header (WAV to RAW), is copying its content to the output file. If you are ready to sacrifice the first 44 bytes of your original raw data (the loss is comparable to loosing a single hair - provided you are not completely bald...), check the Fast format conversion box in the Preferences dialog available from the Options menu. Working in the fast conversion mode, DartPro 32 will do the job almost immediately. When performing the RAW to WAV conversion the system will simply change the extension of the selected RAW file to WAV and replace its first 44 bytes with a wave header. Similarly, if the WAV to RAW conversion is requested, DartPro 32 will change the file extension to RAW and set the bytes comprising a header to zero (otherwise you would hear a loud click at the beginning of the soundfile when playing it back).

    Notice: The system does not support raw PCM files. For this reason, if you perform the fast WAV to RAW conversion, the original wave file will vanish from the screen. If the converted soundfile is registered, it will be also removed from the corresponding audio tree.

54. WAV to RAW - What does this do?

    The uncompressed, and unformatted, string of bytes (for 8-bit sampling) or 'words' (for 16-bit sampling), representing the values of consecutive signal samples, is usually referred to as the 'raw' PCM audio file. When augmented with a header, containing basic information about the recording (sampling rate, sampling resolution, number of channels, number of samples) RAW files become WAV files (WAV stands for a standard Windows format called WAVE). DartPro 32 allows you to convert RAW audio files into WAV files and vice versa.

    WAV to RAW Conversion:

    Input file: source soundfile (*.wav) - ("track01.wav", for example)

    Output file: *.raw (default) - ("track01.raw", for example)

    Processing mode: global

    Conversion of WAV soundfiles into RAW files is much easier and amounts to removing the file header. The WAV to RAW option, available from the File menu, is used for this purpose.

    Fast Format Conversion:

    If the files you want to convert from one format to another are very large (think of one hour of recording, for example), the processing times may be excessive and, in fact, unnecessarily long. You should be aware that all the system is doing after adding the header to the input file (RAW to WAV), or depriving it of the header (WAV to RAW), is copying its content to the output file. If you are ready to sacrifice the first 44 bytes of your original raw data (the loss is comparable to loosing a single hair - provided you are not completely bald...), check the Fast format conversion box in the Preferences dialog available from the Options menu. Working in the fast conversion mode, DartPro 32 will do the job almost immediately. When performing the RAW to WAV conversion the system will simply change the extension of the selected RAW file to WAV and replace its first 44 bytes with a wave header. Similarly, if the WAV to RAW conversion is requested, DartPro 32 will change the file extension to RAW and set the bytes comprising a header to zero (otherwise you would hear a loud click at the beginning of the soundfile when playing it back).

    Notice: The system does not support raw PCM files. For this reason, if you perform the fast WAV to RAW conversion, the original wave file will vanish from the screen. If the converted soundfile is registered, it will be also removed from the corresponding audio tree.

55. File info - What does this do?

    In order to obtain information about an active soundfile, choose the File info command from the File menu or click the INFO button situated on the toolbar.

    The contents of the information window depends on the type of soundfile.

    The basic set of details, displayed for all WAVE files, includes:

    • The number of channels (mono/stereo)
    • The sampling rate (in "KHz")
    • The sampling resolution (in "bits")
    • The length of the file (measured in bytes)
    • The playing time (in seconds)

    When a file is registered as a 'root' soundfile (use the Register button situated inside the File info dialog for this purpose), you have a chance of typing in some more details (recording source, sound card, contents of a soundfile) and comments which will be displayed in the information window.

    The DartPro 32 librarian, called the Soundfile Manager, supervises all restoration experiments that involve 'root' soundfiles, as well as files derived from root files called 'derivative' soundfiles. In particular, the Soundfile Manager adds 'birth certificates' to the information windows of all renovated soundfiles. These 'birth certificates' contain:

    • generation information - the name of the source soundfile
    • processing details - processing tool, the values of processing parameters
    • information about the processing mode - music or music&speech
    • some statistical data - total number of interventions, processing time / real time ratio

56. Register - What does this do?

    If you register the original archive soundfile as a 'root' soundfile, the DartPro 32 librarian, called the Soundfile Manager, will help you to organize and keep track of all renovation experiments involving that file. Soundfile Manager creates and updates special database files "rootname.sfm" which contain information about all files derived from a given root file, and form a 'family tree' called an audio tree. By evoking an audio tree, you can easily review and listen to the results obtained for a particular root soundfile.

    When a file is registered as a root soundfile, you have a chance of typing in some more details (recording source, sound card, and contents of a soundfile) and comments, which will be displayed in the information window each time you click the INFO button.

    Warning: If you change a soundfile's name to "rootname00.wav" outside the Soundfile Manager, the database file "rootname.sfm" will not be created, i.e., the corresponding soundfile will remain unregistered.

57. Exit - What does this do?

    You can use this item to close the program.

    Edit Menu Items:

58. Undo - "What will "Undo last edit" do to my audio?

    Undo basically removes the last edit that was made to the selected file. If you cut out a section of audio, for example, that section would be put back in place...just as if the edit has never happened. Be aware that at this time, there isn't "multiple Undo" support in DartPro 32, and you won't be able to recover anything but the last edit made. This feature has already been added to the list of items to implement in the future.

59. Cut - How can I delete, or cut, selected areas from my audio?

    First, select the block of audio you want to delete.

    Then, after you highlight the block, go to the Edit menu and click Cut.

    This will temporarily store the block of audio that you remove into a holding area, known as the paste buffer.

60. Copy - How can I copy a selected areas from my audio?

    First, select the block of audio you want to copy.

    Then, after you highlight the block, go to the Edit menu and click Copy.

    This will temporarily store the block of audio that you copy into a holding area, known as the paste buffer.

61. Paste Insert - How can I paste in a selected areas from my audio?

    First, Copy or Cut the block of audio you want to paste.

    Selecting Paste Insert will then allow you to insert the cut or copied audio into a file at the point you specify.

62. Paste Over - How do I use this paste option with my selected block of audio?

    First, Copy or Cut the block of audio you want to paste.

    Selecting Paste Over will then act as a mixing effect, because you can paste audio over itself.

63. Paste Fill - "How do I use this paste option with my selected block of audio?

    First, Copy or Cut the block of audio you want to paste.

    Selecting Paste Fill will then allow you to select a block of audio and paste your data only into that block.

64. Save Paste Buffer - "How do I use this paste option with my selected block of audio?

    First, Copy or Cut the block of audio you want to paste.

    Selecting Save Paste Buffer will then save the audio information (that you are waiting to paste), which was cut or copied, into a wave file so that you can use it later.

65. Go To - How can I go to a selected areas within my audio file?

    You can use these commands to move the cursor to specific locations:

    New Position: If you would like to jump to a prescribed position, choose New Position (G) and type in a new cursor coordinate: sample number (if the time axis is calibrated in samples) or time (if the axis is calibrated in units of time). In order to change the method of calibration, check or uncheck the "Time scale in seconds" box in the Preferences dialog available from the Options menu.

    Time can be specified in two different ways - by giving a number of hours, minutes and seconds separated by colons (a digital clock notation) or seconds only. This means you can write either 1:06:40.25 or 4000.25, whichever is more convenient - DartPro 32 will accept both notations.

    Apart from fixing an absolute position of the cursor you can set its relative position within the soundfile, i.e., position expressed as a percentage of the overall file length. To achieve this, enter a positive number smaller than 100.0 and follow it with the percent sign, e.g. write 27.5%. Relative positioning can be used in a very similar way as clicking on the overview strip; it works irrespective of the adopted method of axis calibration.

    Beginning of Block: In order to set the cursor at the beginning of the selected area (block), choose Beginning of the block from the Go To menu or press F11 on your keyboard.

    End of Block: In order to set the cursor at the end of the selected area (block), choose End of the block or press F12 on your keyboard.

    Using "Go To" to scroll through markers:

    To move the cursor to a given marker, or click marker, choose Go to / New position (G), and type in 'm followed by the marker label, e.g., 'm1'. This will move the cursor to the marker labeled 1 and 'mb' will move it to the click marker labeled B.

    Next Marker: To move the cursor to the next marker (in time), use the Go to / Next marker command or press the ">" key on your keyboard.

    Previous Marker: To move the cursor to the previous marker (in time), use the Go to / Previous marker command or press the ">" key on your keyboard.

66. Select local block - What does this do?

    The Select local block command can be used to mark the fragment which is played after choosing Play local from the Play menu (to change the length of this fragment adjust the Local play time in the Setup dialog available from the Options menu).

67. Select modified area - What does this do?

    Use the Select modified area command to mark the block modified when editing a detection file. Detection file editing is discussed within this FAQ.

68. Find bits - What does this do?

    DartPro 32 allows you to browse through a detection file, which is you make within the binary detection file with your mouse will cause the selected bits to 'set' (be set to 1) automatically. This basically forces the outlier detector to run in areas that it may not have before and overrides its previous settings for this area.

69. Clear bits mode - "What does this do?

    Please read the manual sections on Editing signals in binary windows and on perfecting the renovated sound signals in order to get more information about the means and purposes of bit editing.

    The following modes can be used when editing a binary detection file with your left mouse button. Make sure to click on the numbered box (1, 2, 3 or 4) before trying to set, or clear, bits!

    When you select Clear bits mode, any selections you make within the binary detection file with your mouse will cause the selected bits to 'clear' (be set to 0) automatically. This basically forces the outlier detector to NOT run in areas that it may have tried to fix before.

70. Normal mode - What does this do?

    Please read the manual sections on Editing signals in binary windows and on perfecting the renovated sound signals in order to get more information about the means and purposes of bit editing.

    This returns you from the bit-editing mode to the normal editing mode for DartPro 32. You will not be able to set bits, or clear bits, when this mode is engaged.

71. Set bits in selected block - What does this do?

    Please read the manual sections on Editing signals in binary windows and on perfecting the renovated sound signals in order to get more information about the means and purposes of bit editing.

    This function basically works the same as the regular bit editing function, with the exception that it will ONLY work on and with blocks of data. These functions will not have any impact outside of selected block. You can still switch to 'Set bits mode', or 'Clear bits mode' (described above) to work on bits outside of a selected block.

    Set bits in selected block sets the selected block of bits to "1", which forces it through the reconstruct/ReTouch process.

72. Clear bits in selected block - What does this do?

    Please read the manual sections on Editing signals in binary windows and on perfecting the renovated sound signals in order to get more information about the means and purposes of bit editing.

    This function basically works the same as the regular bit editing function, with the exception that it will ONLY work on and with blocks of data. These functions will not have any impact outside of selected block. You can still switch to 'Set bits mode', or 'Clear bits mode' (described above) to work on bits outside of a selected block.

    Clear bits in selected block sets the selected block of bits to "0", which forces them to NOT to be included in the reconstruction/ReTouch process.

73. Toggle bits in selected block - What does this do?

    Please read the manual sections on Editing signals in binary windows and on perfecting the renovated sound signals in order to get more information about the means and purposes of bit editing.

    This function basically works the same as the regular bit editing function, with the exception that it will ONLY work on and with blocks of data. These functions will not have any impact outside of selected block. You can still switch to 'Set bits mode', or 'Clear bits mode' (described above) to work on bits outside of a selected block.

    Toggle bits in selected block switches the status of a selected block of bits back and forth from 'set' to 'clear'.

74. Set/Remove markers - What does this do?

    Markers can be used in the same way as bookmarks - you can place them anywhere in a soundfile to distinguish certain areas of interest (e.g., areas requiring further processing) or to provide a quick way of jumping to specific locations. Markers are distinguished by green vertical lines displayed in soundfile windows (along with the corresponding labels) and on the overview strip. There is no upper limit to the number of markers (labeled with consecutive numbers) that can be associated with a single soundfile.

    To set a marker:

    1. Position the cursor anywhere in an active soundfile window.
    2. Choose the Set /Remove marker command from the Edit menu.
    3. Select the marker label. Each time you enter the Set/Remove marker dialog, the first free label is shown in the Label box. If you choose a number that is assigned to an existing marker, this marker will be automatically removed when inserting the new one.
    4. Click the Set button. The green marker lines (temporarily hidden under the yellow cursor lines) will be added to the active soundfile and to the overview strip.
    5. Press the Close button to close the Set/Remove marker dialog.

    In order to remove a marker, proceed as above but instead of choosing the Set command in step 4, click the Remove button. If you want to remove all markers, use the Remove all button in the same dialog.

    To move to the area where a given marker was placed, open the Set/Remove marker dialog, select the marker label and click on the Go to button. Alternatively, choose the Go to new position (G) command available from the Edit menu and type in 'm' followed by the marker label (e.g., after typing 'm1' you will jump to the marker labeled 1).

    To move cursor to the next or previous marker use the Go to next/previous marker command from the Edit menu or press the ">" or "<" key.

75. Set/Remove click markers - What does this do?

    Click markers are temporary 'soundmarks' which can be placed anywhere in a soundfile and which may help to precisely localize disturbances. Each time you set a click marker, a pulse is added to the sample at the cursor position (negative pulses are added if the sample value is positive and vice versa). Based on listening tests, you can adjust the amplitude of the pulse so as to make the resulting click audible but weak enough to prevent it from screening the disturbance you are trying to spot.

    Click markers are not permanent and do not corrupt the soundfiles they are added to - click pulses are kept in a separate buffer and inserted only at the time of playing back the corresponding fragments. As a consequence, there is no need to remove click markers prior to closing or saving a soundfile.

    Click markers are distinguished by red vertical lines displayed in soundfile windows (along with the corresponding labels) and on the overview strip. Up to eight click markers, labeled A through H, can be associated with a single soundfile.

    1. Position the cursor anywhere in an active soundfile window.
    2. Choose the Set/Remove click marker command from the Edit menu.
    3. Select one of the eight marker labels. The list of all labels shows up when you click the Label arrow in the Set/Remove click marker dialog. Letters associated with the already existing markers are displayed with the 'check' mark next to them. If you choose such a checked letter to label a new click marker, the previous one will be automatically removed. Each time you enter the Set/Remove click marker dialog, the first free label (if any) is shown in the Label box.
    4. Press the PLAY button situated inside the dialog to play the fragment where the click marker will be inserted. If necessary, use the arrows in the Amplitude box to adjust the magnitude of the click. Use Play local from the Play menu to audition the same fragment without the click.
    5. Click the Set button. The red click marker lines (temporarily hidden under the yellow cursor lines) will be added to the active soundfile and to the overview strip.
    6. Press the Close button to close the Set/Remove click marker dialog.

    To remove a click marker: proceed as above but instead of choosing the Set command in step 4, click the Remove button. If you want to remove all markers, use the Remove all button in the same dialog.

    To move to the area where a given click marker was placed: open the Set/Remove click marker dialog, select the marker label and click on the Go to button. Alternatively, choose the Go to new position (G) command available from the Edit menu and type in 'm' followed by the marker label (e.g., after typing 'ma' you will jump to the click marker labeled A).

76. Set/Remove frame - What does this do?

    Frames can be used to isolate disturbances difficult to spot by other means. When looking for an extraneous sound one usually tries to find the smallest segment of a soundfile where the disturbance is localized. One of the possible ways of doing it is to play a selected portion of the sound material gradually shrinking the search area by decreasing the size of the block (when using the Play block command) or increasing the time resolution (when using the Play window command). Unfortunately, as the auditioned fragment becomes shorter and shorter one finds it more and more difficult to judge whether or not it contains the disturbance - exactly as when attempting to analyze an image displayed for a very short period of time.

    An alternative approach, which we call 'framing', amounts to localizing the disturbance at the very beginning and at the very end of two longer, partially overlapping segments, respectively. If the disturbance is present in both fragments of a soundfile it must be contained in their common area and - bingo! - We've got it.

    To set a frame:

    1. Position the cursor so that the disturbance can be heard when the Play local command is used. Please note that the resolution of the frame-based search will increase when the local processing time is decreased. If necessary, use the Preferences dialog available from the Options menu to adjust the local processing time.
    2. Choose the Set/Remove frame command from the Edit menu.
    3. Move position of the upper play buffer in the Set/Remove frame dialog so that the disturbance remains audible and is located at the very end of the buffer.
    4. Move position of the lower play buffer in the Set/Remove frame dialog so that the disturbance remains audible and is located at the very beginning of the buffer.
    5. Click the Set button. The common (shaded) area of two buffers will be distinguished with a light blue frame displayed in the corresponding soundfile window. A similar mark (but in dark blue) will be also added to the overview strip.

    Each time you open the Set/Remove frame dialog the common area of the upper and lower play buffers will be centered on the current cursor position. If so convenient you can adjust position of the cursor either inside the dialog (click anywhere inside the buffer display area) or outside the dialog (use any available way of changing the cursor position). In order to simultaneously shift both play buffers leftward or rightward, change the cursor position and press the Center button - the center of the common area will be moved to the new cursor position. Finally, note that you can change the time resolution and/or the amplitude scale of all displayed plots without closing the Set/Remove frame dialog.

    To remove a frame: invoke the Set/Remove frame dialog and press the Remove button. Note that since only one frame can be placed in a given soundfile window, when a new frame is added the previous one is automatically cancelled.

    In order to position the upper/lower play buffers appropriately use the control buttons situated inside the Set/Remove frame dialog:

    Left arrow (only): Moves the buffer leftward
    Right arrow (only): Moves the buffer rightward
    Single triangle: Plays contents of the buffer
    Dual triangle (pointing in): Plays in a short succession the contents of the upper and lower buffer, respectively.
    Dual triangle (pointing out): Plays the contents of the common area of two buffers.

    NOTICE: Frames are not permanent, i.e., the frame is not restored when the corresponding soundfile window is closed and opened again. However, you can save the current position of all frames by saving a group of soundfiles (choose Save as from the Group menu).

    Group Menu Items:

77. What is 'grouping'? Why would I use it?

    At any time, any given collection of opened files can be saved as a group of files. When saving such a group, DartPro 32 creates a configuration file, "groupname.dgr", which contains information about the current system status including the list of opened files, the source/destination assignment, synchronization details, cursor, marker and frame positions, resolution and scale settings etc. Because of this, whenever you open an existing group, you will find everything in exactly the same order as at the time of saving. You might find group saving/opening facilities particularly useful when working on complex projects requiring long and multistage processing.

78. How does grouping work?

    The Group menu contains several items for handling groups of files.

    New - this command saves and closes the currently open group of files and creates a new (empty) one with a default name "NoName.dgr". You can use New to clear the entire DartPro 32 desktop without the need to close open windows one by one. Using New has the same effects as quitting DartPro 32 and starting it again, except that all current system settings are preserved (i.e. they are not changed to the default ones).

    Open - this command saves and closes the currently open group of files (if any) and opens a new (existing) group.

    Save - use this command to save a group of open files under a current group name.

    Save as - use this command to save a group of open files under a new group name.

    WARNING: The file "groupname.dgr" is a configuration file only, i.e., it does not store information about the contents of the files comprising a group. For this reason, if you delete or modify any of the files after saving a group, you will not be able to retrieve a group in its original form.

    Toolbox Menu Items:

79. What is "Scale"? What does it do and how does it work?

    Scaling allows you to amplify (turn up the volume) or attenuate (turn down the volume) a selected block or the entire sound file. The scaling 'factor' controls the level of amplification or attenuation. For example, scaling factors set below one (0.5, for example) result in signal attenuation and factors greater than one (1.5, for example) cause signal amplification. Be careful when you amplify the sound, because parts of the audio that may be "sticking out" before scaling could clip if the scaling factor is set too high. To avoid this mishap, you can use 'Find maximum gain' and the program will set a limit so that no clipping will occur after scaling the file.

80. What is "Maximize"? What does it do and how does it work?

    Maximize is much like scaling in that it amplifies the volume of an audio file. Sometimes called "Normalize", maximize raises the volume of the sound file to its highest point without clipping the audio. A benefit of using this function is that sometimes there are imbalances in a sound file's volume, and using maximize could "balance out" the entire file.

81. What is "Mute"? What does it do and how does it work?

    Muting basically means making a selected area completely silent or turning the volume all the way off.

    To use the mute function from the toolbox menu, select the block of audio that you wish to silence, then click on Mute from the toolbox menu.

82. What is "Reverse"? What does it do and how does it work?

    "Reverse" means to play a song backward, much like forcing an LP to run in reverse. If you perform Reverse on a file, and listen to the results, it will be pretty clear what it does.

    This option allows you to reverse an entire signal or a fragment. This is especially useful in certain instances. For instance, you may derive superior results through reverse-time that are superior to what can be achieved through normal processing. Sometimes, when you are DeClicking a sound file, you may get better results after a regular DeClick, by reversing the sound file and then DeClicking again. This is because, the shape of a wave file at the beginning of a noise disturbance like a click could sometimes be more defined when it is reversed. Therefore, the program will recognize more noise disturbances, and the quality of the result file that was reversed will probably transcend the quality of the file where reverse was not used.

    Reversing can also be used for more recreational purposes, such as revealing hidden backwards messages embedded within songs and music. These types of messages where especially popular among the counter-culture groups of the 1960's and 1970's.

83. What is "Compare"? What does it do and how does it work?

    Compare is used to compare the difference between a restored file and a renovated file. Make sure the destination and the source file are open, and then choose Compare from the toolbox menu.

84. What is "Mix"? What does it do and how does it work?

    Mixing is used when you what to combine two files together. You get the effect of two sources of music playing simultaneously.

    To Mix two files together:

    1. Open a file and designate it as the source file.
    2. Open the second file and designate it as the destination file.
    3. Open the toolbox and click on the Mix function.
    4. You can adjust the volume settings for the two files and audition the mix before you process.
    5. Click Process when you are satisfied with your results.

85. What is "Split"? What does it do and how does it work?

    This is used to separate, or 'Split' the channels of a stereo recording into two mono sound files, containing the left and right channels of the original file. This is especially useful when you want to work with only one channel of a stereo recording.

86. What is "Unite"? What does it do and how does it work?

    This is used to combine, or 'Unite', two mono files in to one stereo file. The resulting file contains the information of the mono files in the left and right channels (one mono file goes to the left channel and the other file goes to the right channel to form a stereo file).

87. What is "Mono"? What does it do and how does it work?

    This allows you to convert a stereo sound file into a mono sound file by mixing the left and the right channels.

88. What is "Stereo"? What does it do and how does it work?

    This allows you to convert a mono sound file to a stereo sound file by duplicating the mono track.

89. What is "Equalize"? What does it do and how does it work?
    1. Select the source file that you want to equalize.
    2. Open the Toolbox menu and select Equalize.
    3. Use the Preview processing function by clicking the Play Result button and making the necessary adjustments.
    4. When you are satisfied with the equalization you can click the Process button.

90. What are the "Filter" tools? What do they do and how do they work?

    Lowpass filter: Used to remove high frequency components of the signal, starting from a desired cutoff frequency.

    Highpass filter: Used to remove all low frequency components of the signal, up to a desired cutoff frequency.

    Bandstop filter: Used to remove from the analyzed signal the middle, or "mid", frequency components. These are the frequencies between the high and low cutoff frequencies. This is basically the reverse of the Bandpass filter.

    Bandpass filter: Used to remove from the analyzed signal both the low frequency components and the high frequency components. In other words, it only allows frequencies between the lower and higher cutoff frequency values to pass. So, if you set the low at 200Hz and the high at 3500Hz, you would ONLY have the portions between those values left over after processing. This is basically the reverse of the Bandstop filter.

    Notch filter: Designed to remove the components contained in a very narrow frequency band centered at a given notch frequency. It is very useful in removing narrow band interference due to the power supply or electrical coupling.

    How to use these filters:

    Depending on what type of frequency you want to suppress you will use one of these filters.

    1. Open up the sound file that you want to work with.
    2. Select the appropriate filter.
    3. Make the appropriate adjustments to the settings and audition the settings using real time processing.
    4. When satisfied with the settings, click on the "Process" button.

91. What are the "Fade" tools? What do they do and how do they work?

    Fade utilities can be used to gradually increase the volume of the recording at the beginning of the soundfile (Fade in), gradually decrease the volume of the recording at the end of the soundfile (Fade out) or to fade one soundfile into another (Crossfade).

    Fade In: You can use this option to gradually increase the volume of the recording at the beginning of the soundfile. The Fade in dialog allows you to:

    • Select the fade range (anything between 20 ms and 20 s)
    • Select the start level specified in decibels (-96dB corresponds to a total silence); the end level is always assumed to be 0dB, which corresponds to the original volume of the audio.
    • Select the type of the volume change (linear or logarithmic)
    • Audition the modified fragment of the recording

    NOTICE: You can specify the fade range both in milliseconds and samples. Use the wide scroll buttons for a coarse range selection and the narrow ones for fine-tuning. Alternatively, type the desired value directly in the corresponding text box.

    Fade Out: You can use this option to gradually decrease the volume of the recording at the end of the soundfile. The Fade out dialog allows you to:

    • Select the fade range (anything between 20 ms and 20 s)
    • Select the end level specified in decibels (-96dB corresponds to a total silence); the start level is always assumed to be 0 dB, which corresponds to the original volume of the audio
    • Select the type of the volume change (linear or logarithmic)
    • Audition the modified fragment of the recording

    NOTICE: You can specify the fade range both in milliseconds and samples. Use the wide scroll buttons for a coarse range selection and the narrow ones for fine-tuning. Alternatively, type the desired value directly in the corresponding text box.

    Crossfade: You can use this option to crossfade the source soundfile into the destination soundfile. The crossfade point (i.e., the point around which one audio file is is faded out and the other one is faded in) is determined by cursor positions in the source and destination soundfile, respectively. Typically, the crossfade point is placed close to the end of the source file and close to the beginning of the destination file which allows one to achieve a smooth transition from one recording to another. In order to be able to freely and independently set cursor positions in crossfaded files, switch the cursor synchronization off prior to using this option.

    To crossfade two audio files:

    1. Indicate the source and destination soundfiles due to be crossfaded.
    2. Use the Synchronization dialog (available from the Window menu) to turn the cursor synchronization off. Alternatively, press the SYNCHRONIZE button situated on the toolbar to switch off the synchronization completely.
    3. Set the cursor positions in the source soundfile (fade out point) and in the destination soundfile (fade in point).
    4. Select the fade range (anything between 20 ms and 20 s) and the type of the volume range (linear or logarithmic).
    5. If necessary, change the name of the output file.
    6. Audition the results.
    7. Press the Process button to start processing.

    NOTICE: You can specify the crossfade range both in milliseconds and samples. Use the wide scroll buttons for a coarse range selection and the narrow ones for fine-tuning. Alternatively, type the desired value directly in the corresponding text box.

92. How and when do I use Resample?

    Resample is used when you want to change the sampling rate of a sound file. For example, you might have a file that is in 22kHz and you may want to change it to 44kHz. You can use the resample tool to do this. Since all CD players "read" audio signals with a 44.1kHz speed you have to convert all audio files to this standard rate prior to putting it on a CD. The other standard output rates are, among others, 48kHz (the rate used in a DAT equipment) and 32kHz (the radio frequency). The procedure for sample rate conversion implemented in DART Pro has two important features:

    1. It provides truly professional resampling quality and, at the same time, is extremely fast (we bet you will not find a faster one elsewhere).

    2. It is not constrained to standard sampling rates, i.e., it can be used to convert any input rate to any output rate.

    When the output/input resampling ratio r is greater than one (upsampling) the output audio file is r times longer than the input one. If r is smaller than one (downsampling), the output file is r times shorter than the input file. For obvious reasons downsampling is faster than upsampling (think of the number of input/output operations in each case). When downsampling is performed, the bandwidth of the signal is reduced accordingly, that is, some high-frequency signal components are removed. This means that downsampling an audio signal r times and then upsampling it r times will not restore the original recording (downsampling is not a reversible operation). Since bandwidth reduction may result in audible sound distortions you should use this tool with caution.

    NOTICE: The bandwidth of many old recordings is limited to 10kHz which means they can be "safely" sampled at the rate of 22kHz. In cases like this consider recording and restoring the audio signal at a lower rate of 22kHz prior to upsampling it to a CD rate of 44kHz. There are at least two advantages of doing this:

    1. DeClicking is usually more effective at low sampling rates - at high rates clicks are less sharp and hence more difficult to detect and isolate. The same, to some extent, concerns denoising - since noise dominates the high-frequency portion of the signal spectrum, fast sampling decreases the overall signal-to-noise (SNR) ratio, which makes the restoration task more difficult.

    2. Since resampling is less time consuming than declicking or denoising (dehissing) the "restore at lower rate and "upsample" scheme works considerably faster than the "restore at higher rate" scheme.

    Time synchronization:

    Comparing the resampled audio signal with its original version is a bit tricky - since both files differ in length the 'ordinary' synchronization, which does not take into account the sampling rates of displayed files, will fail to locate fragments of the recordings with identical contents. To help you compare several variants of the recording with different sampling rates a special time synchronization feature was added to the Options dialog available from the Setup menu. When the Time sync box is checked and synchronization is switched on the cursors in all displayed windows are automatically time-aligned. This means that if the Play local command is used the same portion of the audio material will be played back irrespective of the corresponding sampling rates. Similarly, when a block of samples is selected in an active window the appropriately scaled (contracted or extended) blocks will be marked in the remaining windows.

    NOTICE: When time synchronization is on and the compared files have different sampling rates, the time-aligned cursors have different relative positions within each window (unless placed exactly in the center of an active window). To put them exactly one over another, i.e., along the same vertical line, press the TAB key.

93. How and when do I use Adjust Sample Rate?

    Adjust RPM Rate allows you to convert an audio file from one RPM rate to another. For example, if you do not have a turntable that supports 78-RPM recordings you can convert the audio file into 78 RPM after recording from the record player.

    You can use this option to change the speed at which a soundfile is played back. Since all the system does is modify the file header (all signal samples remain unchanged) speed adjustments can be made in no time. Many cards will allow you to precisely tune the sampling frequency over a wide range of speeds - even though the recording rate is usually limited to a certain number of standard frequencies. Should the card be unable to support a declared playing speed the system will issue an appropriate message each time you attempt to play the corresponding audio file.

    Speed adjustments can serve different purposes. Since speeding up an audio file raises the pitch and slowing it down lowers the pitch you can make someone sound like Donald Duck or you can make your poodle sound like a bulldog. But seriously ...

    Speed adjustment is a very useful tool should you have to deal with audio material recorded or played back at nonstandard rates. Suppose, for example, that you want to restore recordings from an old 78-rpm (revolutions per minute) vinyl record but you don't have a phonograph capable of playing it back with the appropriate speed. Here's what you can do if you have at your disposal a 33 1/3-rpm phonograph which was in common use prior to the invasion of CD players (check out your attic!)

    1. Play the record back with a speed of 33 1/3-rpm and sample it at a standard rate of 22050 Hz.
    2. Use the Adjust rate utility to change the sampling rate of the obtained recording from 22050 Hz to (78 : 33 1/3)22050 Hz = 51598 Hz.
    3. Use the Resample utility to convert the recording obtained at step 2 to a standard sampling rate of 44100 Hz.

94. How and when do I use Trim Length?

    Trim length allows you to speed up audio data of a single song or an entire compilation without audibly changing the sound of the music (changing the speed by more than 5% may damage the quality of an audio file). This is used when you have a number of songs that you want to write to CD, but you pass the limit by a minute or so. Trim length will speed up the audio just enough so that you can fit all of the songs on the CD that you want without audibly distorting the sound files.

    Suppose there are exactly 3 minutes left on your recordable CD and the recording you would like to include is 3 minutes and 5 seconds long ... Suppose there are exactly 3 minutes left on your recordable CD and the recording you would like to include is 3 minutes and 5 seconds long ... The easiest way to cope with such a situation is to 'shorten' the material while keeping the original sampling rate unchanged. Of course, all length alterations affect the pitch of the audio signal. However, if the changes are not significant, e.g., if the new length does not differ by more than +/- 5% from the old one, pitch variations remain practically unnoticeable.

    The Trim length dialog allows you to freely adjust the length of the recording by means of specifying the new length expressed in time units, bytes or as a percentage rate. If the attempted changes are not cosmetic, i.e., they exceed the +/- 5% safety margin, the red 'safety alert' light is turned on to warn you of possible hazards.

95. How and when do I use CD format?

    CD Format converts the selected "source" file into 44kHz and 16 bit. The source file's original sample rate or bit depth are not taken into account, as this function converts whatever it is given to the standard CD audio format which allows the new to be written on to CD.

96. How and when do I use the Find pattern function?

    Find Pattern is a great tool to use when trying to detect noise disturbances throughout a file. Noises like thumps, clicks, pops, and scratches are commonly identical in their waveform and repetitive throughout the audio file. Find pattern can be used to locate these disturbances so superior restoration can be achieved.

    To use the find pattern function:

    • Select a block of audio, at least 50 samples and no more than 500 samples that you want to locate throughout the audio file.
    • Click on the toolbox menu and click on find pattern.
    • When the find pattern dialogue box opens, click on the get button to load the pattern in to memory.
    • Adjust the accuracy factors according to how discriminating you want the find pattern function to be when looking for identical bits.
    • Use the arrows to search for the next available identical audio bit in the sound file.

    Note: You can work with the audio file while the find pattern dialogue box is still open. Minimize the dialogue box when you need to work with the audio file.

97. How and when do I use Spectrum or Spectral View?

    WARNING! The following sections on spectral information can get quite detailed and scientific. So, if you're not sure that you need to use this capability, or if none of this makes sense, you're probably in the wrong place. This is not for an area for beginners! These tools can be very useful, but can also be difficult to learn and use if you're new to audio or measurement tools and techniques.

    General Spectrum information:

    Spectral graphs of the audio information can be viewed in two different ways: using a full size spectral analysis dialog (with a 512-point graphic display) or using a reduced size dialog (with a 128-point display).

    The extended, full size dialog allows the following choices for spectral estimation:

    • FFT (fast Fourier transform) or AR (autoregressive)
    • Selection of the scale (linear or logarithmic)
    • The mode of display (automatic normalization or automatic updating).

    The full size window also allows for precise reading of the plots (the value of the spectral density function for a particular frequency). The reduced size dialog can be used for fast spectrum previewing.

    You can switch between the two dialogs at any time by pressing the MINIMIZE/MAXIMIZE button, situated in the upper right corner of each window. Whenever you select the Spectrum command (available from the Toolbox menu) or press the SPECTRUM button (situated on the toolbar) a spectral analysis dialog will be shown. The last-used spectral form, or type, will be shown automatically (i.e., if you close the reduced size dialog and press the SPECTRUM button the small dialog will appear again).

    The material for spectral analysis is always taken from an active soundfile. If the Auto switch is on (i.e., the analyzer works in the automatic update mode), the processed fragment is centered around the current cursor position and spectral graphs are redrawn each time you change position of the cursor within an active soundfile or switch between different soundfiles. If your computer is fast enough, you can even watch the spectrum changing while the soundfile is played back (for slower machines problems with skipping may occur).

    When a block of samples is marked in an active soundfile, and the Auto box is unchecked (and only in this case), DartPro 32 will display an average spectrum of a selected portion of the audio material each time you press the Update button. Finally, when you press the SPECTRAL VIEW button (situated between the Update button and the Close button), DartPro 32 will display a spectral panorama of the signal centered on the current cursor position. A spectral panorama, often called an evolutionary spectrum (as it shows how the signal spectrum evolves in time), is a sequence of spectral graphs corresponding to different time instants.

    Spectral Estimation:

    Spectral frequency analysis techniques can be broadly classified into 2 'flavors':

    • Non-parametric: Fourier analysis based methods (periodogram approach)
    • Parametric: model based methods (autoregressive approach)

    DartPro 32 offers users both methods of frequency analysis.

    Non-parametric estimates - the periodogram approach:

    The basis for this method is the Fourier transform of the analyzed sequence - the fast Fourier transform (FFT) algorithm is used for the purpose of transform evaluation. The Periodogram approach can yield very 'bumpy' spectral plots, especially if the analyzed signal is noise-like. On the other hand, this approach guarantees high spectral resolution and the ability to distinguish between the closely spaced frequency components.

    By default, the spectral analysis is performed on a block of 1024 samples centered at the current cursor position. You can change the size of the analysis frame by picking another value from the Frame list placed inside the FFT group.

    In order to improve consistency of spectral estimates, it is recommended that the Fourier transforms be weighted prior to periodogram evaluation - the Goodman-Enochson-Otnes (GEO) window is used for this purpose. If the Windowing box is not checked, the results of spectral analysis may be overly sensitive to the position and size of the analysis frame. Without windowing, they may also be inconsistent with the results of parametric analysis, especially in the region of high frequencies.

    Parametric estimates - the autoregressive approach:

    Parametric spectral evaluation techniques are model based. This means the parameters of the mathematical model of the analyzed time series are the basis for spectrum estimation. DartPro 32 adopts the so-called autoregressive (AR) model for this purpose. The Burg lattice algorithm is used for estimation of autoregressive coefficients.

    The parametric approach yields spectral graphs that are smooth and, therefore, easy to interpret. Since the number of resonant peaks this method is capable of distinguishing depends on the number of model coefficients (at least 2k parameters are needed to match spectrum with k peaks), it is important to make the right choice of the order of the adopted AR model.

    • Low order models may yield spectral plots that do not reflect all details of the true spectrum.
    • On the other hand, if the order of the AR model is too high, the corresponding graphs will tend to show spurious peaks.

    To choose the preferred order of autoregression:

    • Select from the available Order values (4, 8, 12, 16 or 20) from the list in the AR section. "12" should be fine in most cases.
    • If you want DartPro 32 to make this decision for you, choose Auto from the top of the list. The applied procedure of automatic order selection is based on the Akaike's information criterion (AIC).

    Since the parametric approach gives satisfactory results even if the analyzed data segments are relatively short, the default size of the analysis frame was set to 256 - you can change it by choosing another value from the Frame list placed inside the AR section.

    Which approach is better?

    There is no clear-cut answer to this question. Each of the two approaches described above has both advantages and limitations. Due to a large number of degrees of freedom, the nonparametric estimates form pretty ragged patterns, which may be difficult to interpret. The plots obtained using the parametric approach are smooth and, therefore, easy to analyze. On the other hand, a periodogram, as with all FFT-based methods, yields "unprejudiced" spectral estimates, in the sense that the number of resonant peaks is not limited a priori. In contrast with this, the results of parametric analysis may strongly depend on the order of the adopted model.

    DartPro 32 allows you to use both methods of spectral analysis simultaneously - the plots are superimposed. Whenever you want to inspect the results of either parametric or nonparametric analysis, uncheck the corresponding boxes (FFT or AR, respectively) in the extended spectral dialog.

    In most cases, the superimposed plots stay in a good agreement. Whenever discrepancies occur remember that:

    • Only the dominant periodogram peaks correspond to spectral resonances.
    • The graphs obtained using the parametric approach tend to show too many spectral peaks if the order of autoregression is too high; if the order of the AR model is too low, some resonances might be overlooked.
    • The AR estimates have a tendency to better match spectral peaks (resonances) than spectral valleys (anti-resonances).
    • Both approaches may give different and/or dubious results if the processed signal is not locally stationary, e.g., if you analyze a fast speech transient - we recommend you use short analysis frames in all such situations.

    Spectral Graphs:

    Scale:

    The vertical scale used to display spectral graphs may be linear or logarithmic (default). In the latter case, you can set the dynamic range of display by means of adjusting the "spectral floor", i.e., the lowest amplitude level (in decibels) displayed in the graph - use the Min list situated in the Scale section for this purpose. The logarithmic scale is usually preferred to the linear one, as it is better matched to the sensitivity characteristics of our auditory system.

    NOTICE: Remember that a difference of ten decibels in the logarithmic scale is equivalent to a difference of one order of magnitude (ten times) in the linear scale.

    Readings:

    DartPro 32 can yield precise reading of the displayed spectral plots. The value(s) of the spectral density function(s) for a particular frequency (marked with a gray vertical line) is/are listed in the Info window situated in the upper right corner of the graphic display. The frequency readings are provided just below the display area, inside the Spectral graph group.

    To change the position of the frequency marker:

    • Locate the pointer anywhere inside the plot area and press the left mouse button. Clicking and dragging the mouse will allow you to sweep the available frequency range (from zero to half of the sampling frequency).
    • For fine-tuning, use the right mouse button. Pressing this button when the pointer is on the left/right hand side of the frequency marking line will move the line by one pixel to the left/right (which corresponds to decreasing/increasing the frequency coordinate by the 1/1024th of the sampling frequency)

    If convenient, you can change position of the Info window by means of dragging it and dropping at a new location. Finally, if all that you need is qualitative evaluation of spectral graphs you can remove the Info window and the frequency marker by un-checking the Info box in the Spectral graph group.

    Automatic updating:

    When the Auto box is checked all spectral plots are automatically updated each time you change position of the cursor within a soundfile, switch between different soundfiles or modify spectrum settings. This also means that spectral graphs will be continuously updated when an active soundfile is played back.

    If your computer is not fast enough, automatic updating may create some problems, e.g., skipping may occur during playback or the system may react too slowly when browsing through the soundfiles. Should anything like this happen, simply uncheck the Auto box and the plots will be redrawn only when you press the Update button. Finally, remember to uncheck the Auto box each time you want to perform spectral analysis of a segment (block) of data.

    Automatic normalization:

    Theoretically, the power spectral density function can take any positive value, i.e., it has no "natural" upper limit. For this reason only the relative normalization of spectral graphs can be performed, i.e., normalization with respect to the locally observed maximum value of the density function. When the Normalize box is checked, the highest point of all displayed graphs is assigned the value 100% (for a linear scale) or 0 dB (for a logarithmic scale); the values corresponding to the remaining points are then adjusted proportionally.

    If you wish to compare two (or more) spectral graphs, automatic normalization is NOT the best idea. In all such instances, uncheck the Normalize box while viewing a particular spectral graph - this graph will be further regarded as a 'reference' one. From this point on, all spectral plots will be scaled with respect to the reference plot - until you check the Normalize button again. Please remember that if normalization is switched off, some graph points may fall out of the viewing range.

    Left/right channel selection:

    If both channels of an active stereo soundfile are displayed, the corresponding spectral graphs are superimposed. In order to view plots relatively large values of detection threshold are adopted, the detector may become to "tolerant" and fail to isolate small noise pulses. Un-checking the detection threshold will turn of the device. However, if smoothing and Postfiltering are unchecked as well then the resulting file will be identical to the original one.

98. Maximum Length of Detection Alarms: The maximum length of detection alarms, which can be chosen in the range <1,100>, determines the maximum number of samples in a row that can be scheduled for reconstruction in the automatic detection mode. We recommend you use the default value of 50.

99. You may want to change the name of your new file, and you can do this by clicking on the "Change" button. When the dialogue box pops up, enter the name you want to use, and click Save.
100. You are now ready to DeClick. Click on the Process button.
101. After the processing is complete, your file will be created with the resulting changes.

You can now play the new file to make sure it is to your liking.