Here's how to do it with TSF, which changes highlighted in bold:

1. Create an empty level in JCS, except maybe a background and a floor with Jazz Start on top of it. Place 5 ambient sounds, left to right, with sample numbers 14, 27, 44, 47 and 104 anywhere in the level.
2. Save the level as tweedle.j2l
3. Open regedit and go to HKEY_CURRENT_USER\Software\Epic MegaGames\Jazz Jackrabbit 2 Special Edition\1.24\Player0
4. Set the value of Char to "60 00 00 00"
5. Run JJ2 with the command line "jazz2 -server tweedle.j2l"

You can reset Char by just going into the player setup screen the normal way from the main menu -> party mode etc..