Many, many, many years ago, I bought a cheap used paperback book called “Four Channel Sound” by Leonard Feldman. I bought this so long ago that I forgot I even owned it. But I came across it last night, and thought “Wow! Now that I’m actually collecting quad recordings, this may come in handy . . . for something.” I wasn’t sure what, but I read through the book, and came to a section on Dynaquad. Eureka! I had started a discussion a while back on whether a script for Adobe Audition could be written for decoding Dynaquad encoded recordings, but there was no real consensus in the answers.
https://www.quadraphonicquad.com/forums/showthread.php?t=6857
What this book told me is that Dynaquad means two different things. The early Dynaquad was simply a diagram for hooking up your speakers so that the L-R signal was sent to the rear speaker(s). The Quadapter decoder, however, handled things a little differently. Its output was:
Lf = Lt
Rf = Rt
Lb = .64 Lt - .36 Rt
Rb = .64 Rt - .36Lt
(f=front, b=back,t=total)
Heck, I thought, maybe I can record my own script in Adobe Audition. Here is what I came up with:
1. Place three copies of your recording in a directory called c:\dynaquad. Call the three files rear_left.wav, rear_right.wav, and whatever you want for the original, which will not be processed.
2. Open Audition, and run this script (paste this text into a Notepad file, and save it as dynaquad.scp in the Audition scripts subdirectory):
Collection: dynaquad
Title: dynaquad
Description:
Mode: 1
Undo: 0
cmd: Channel Both
cmd: Command 1100
1: C:\dynaquad\rear_left.WAV
2: ý
Selected: 0 to 84350663 SR 44100
Freq: Off
Comment: Amplitude\Channel Mixer
cmd: {4EB62A8D-32F7-4515-8C90-919A17A50EE5}
1: 1
2: 0
3: 0
4: 1
5: 0
6: 1
7: 0
Freq: Off
cmd: Convert
1: 44100
2: 1
3: 16
4: -1
5: 0.64
6: 0.36
7: 1
8: 0
9: 150
10: 1
11: 1
12: 16
Freq: Off
cmd: Command 1100
1: C:\dynaquad\rear_right.WAV
2: +
Freq: Off
Comment: Amplitude\Channel Mixer
cmd: {4EB62A8D-32F7-4515-8C90-919A17A50EE5}
1: 1
2: 0
3: 0
4: 1
5: 1
6: 0
7: 0
Freq: Off
cmd: Convert
1: 44100
2: 1
3: 16
4: -1
5: 0.36
6: 0.64
7: 1
8: 0
9: 150
10: 1
11: 1
12: 16
Freq: Off
End:
3. After the script has run, your rear_left.wav and rear_right.wav files will be mono signals. Open the original unprocessed file, and then place all three files into three tracks in the multitrack view.
4. Open up the surround encoder (ctrl-E), and place the files in their proper panning assignments.
Now I just need to find some Dynaquad encoded albums other than my Environments albums.
By the way, someone suggested in an earlier thread that Dynco did not build a specific Dynaquad encoder. According to “Four Channel Sound,” Dynaco did build a Dynaquad encoder using the following coefficients:
Lt = Lf +.25Rf +Lb -.5Rb
Rt = Rf +.25Lf +Rb -.5Lb
(These values don’t seem to correspond with the decoding coefficients to me, but what do I know).
J. D.
https://www.quadraphonicquad.com/forums/showthread.php?t=6857
What this book told me is that Dynaquad means two different things. The early Dynaquad was simply a diagram for hooking up your speakers so that the L-R signal was sent to the rear speaker(s). The Quadapter decoder, however, handled things a little differently. Its output was:
Lf = Lt
Rf = Rt
Lb = .64 Lt - .36 Rt
Rb = .64 Rt - .36Lt
(f=front, b=back,t=total)
Heck, I thought, maybe I can record my own script in Adobe Audition. Here is what I came up with:
1. Place three copies of your recording in a directory called c:\dynaquad. Call the three files rear_left.wav, rear_right.wav, and whatever you want for the original, which will not be processed.
2. Open Audition, and run this script (paste this text into a Notepad file, and save it as dynaquad.scp in the Audition scripts subdirectory):
Collection: dynaquad
Title: dynaquad
Description:
Mode: 1
Undo: 0
cmd: Channel Both
cmd: Command 1100
1: C:\dynaquad\rear_left.WAV
2: ý
Selected: 0 to 84350663 SR 44100
Freq: Off
Comment: Amplitude\Channel Mixer
cmd: {4EB62A8D-32F7-4515-8C90-919A17A50EE5}
1: 1
2: 0
3: 0
4: 1
5: 0
6: 1
7: 0
Freq: Off
cmd: Convert
1: 44100
2: 1
3: 16
4: -1
5: 0.64
6: 0.36
7: 1
8: 0
9: 150
10: 1
11: 1
12: 16
Freq: Off
cmd: Command 1100
1: C:\dynaquad\rear_right.WAV
2: +
Freq: Off
Comment: Amplitude\Channel Mixer
cmd: {4EB62A8D-32F7-4515-8C90-919A17A50EE5}
1: 1
2: 0
3: 0
4: 1
5: 1
6: 0
7: 0
Freq: Off
cmd: Convert
1: 44100
2: 1
3: 16
4: -1
5: 0.36
6: 0.64
7: 1
8: 0
9: 150
10: 1
11: 1
12: 16
Freq: Off
End:
3. After the script has run, your rear_left.wav and rear_right.wav files will be mono signals. Open the original unprocessed file, and then place all three files into three tracks in the multitrack view.
4. Open up the surround encoder (ctrl-E), and place the files in their proper panning assignments.
Now I just need to find some Dynaquad encoded albums other than my Environments albums.
By the way, someone suggested in an earlier thread that Dynco did not build a specific Dynaquad encoder. According to “Four Channel Sound,” Dynaco did build a Dynaquad encoder using the following coefficients:
Lt = Lf +.25Rf +Lb -.5Rb
Rt = Rf +.25Lf +Rb -.5Lb
(These values don’t seem to correspond with the decoding coefficients to me, but what do I know).
J. D.
