I decided to write out the process I'm using, partially so I don't forget and partially to share. Here's what I've been doing:
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Convert stereo audio to 5.1 DTS surround
Programs Needed:
Goldwave
Surcode DTS Encoder
Part 1 - Goldwave
Open the audio file in Goldwave. The sample rate needs to be either 44.1 khz or 48 khz. If it not already one of these formats, click on "Effect -> Resample",
choose 44.1 or 48 khz depending on the current sample rate, and click "OK" to resample the audio.
Click on "File -> Save As...," at the bottom of the window set the "Save as type" option as "Wave" and the "Attributes" option as "PCM signed 16 bit, stereo." Select
a location, name the file "source.wav" or something similar and click the "Save" button.
Click on "Edit -> Channel" and select "Left." Click on "File -> Save Selection As...," verify the "Attributes" option is set to "PCM signed 16 bit, mono," and save
the file as "Left Front.wav" or something similar.
Click on "Edit -> Channel" and select "Right." Click on "File -> Save Selection As...," verify the "Attributes" option is set to "PCM signed 16 bit, mono," and save
the file as "Right Front.wav" or something similar.
Click on "Edit -> Channel" and select "Both." Click on "Effect -> Stereo -> Reduce Vocals," use the default settings, and click "OK" to process the file then click
on "Effects -> Invert".
Click on "Edit -> Channel" and select "Left." Click on "File -> Save Selection As...," verify the "Attributes" option is set to "PCM signed 16 bit, mono," and save
the file as "Left Surround.wav" or something similar.
Click on "Edit -> Channel" and select "Right." Click on "File -> Save Selection As...," verify the "Attributes" option is set to "PCM signed 16 bit, mono," and save
the file as "Right Surround.wav" or something similar.
Close the file and, when asked if you want to save, click "No." Reopen the "source.wav" file and click on "Effect -> Filter -> Low/Highpass." Under the "Settings"
section, click the radio button next to "Dynamic" on the right-hand side. Now change the settings to the following:
Under Cutoff Frequency:
Initial Cutoff = 80
Final Cutoff = 120
Under Settings:
"Lowpass" selected
"Dynamic" selected
Steepness = 5
Click "OK" to process the audio, click on "File -> Save As...," set the "Attributes" option to "PCM signed 16 bit, mono," and save the file as "LFE.wav" or something
similar.
Close the file and reopen the "source.wav" file. Click on "Effect -> Stereo -> Stereo Center," use the default settings, and click "OK" to process the file. Click on
"File -> Save As...," set the "Attributes" option to "PCM signed 16 bit, mono," and save the file as "Center.wav" or something similar.
Now you should have 6 seperate .wav files.
Part 2 - Surcode DTS Encoder
In Surcode DTS Encoder, click on "Setup -> New" to clear out any previous settings.
Click on "Options -> Encoder Options...," Set the "Sample Rate" option to match the sample rate of your source files, put a check in the box next to "Attenuate Rear
Channels 3dB" and click "OK." The "Attenuate Rear Channels 3dB" works well on music and most audio but if you notice that the surround channels sound too quiet you
can leave the box unchecked.
Click on the buttons for the front, center, LFE, and rear channels and load the corresponding .wav files. Click on the "Destination" button and set a location and
filename for the new file. For best results, save the file as either a DTS Wave file or padded DTS file.
Click the "Encode" button to encode the audio after verifying that the "Start" option is set to 00:00:00.00 and the "End" option is set to the end of the audio.