WC2 DosBox Solution
The problem is not with dosbox.
When you are at the cdrom drive prompt in dosbox and you type wc2, what loads is not wc2.exe, but wc2.bat wich then loads options (including the audio) before calling wc2.exe.
If you execute the command:
loadfix -32 wc2
You are actually using the loadfix -32 command to load the wc2.bat file which then calls the wc2.exe without loadfix.
You will have to duplicate the entire wingcommander cdrom to your hard disk. Just create a new directory and copy the contents of the cdrom to that directory. When loading dosbox, mount that directory as the cdrom drive by typing:
mount D c:\wc2cdr\ -t cdrom
Next edit the wc2.bat file. You may notice all commands in the bat file are local to the cdrom drive, that is why you must copy the cdrom to your hard disk for this to work unless you know how to hack the bat file (I'm didn't do it because I like having it on my hard disk anyway). Scroll to the bottom of the wc2.bat file and find the line that looks like this.
wc2.exe %1 %2 %3 %4
edit that line to look like this (note you can substitute any value from 1 to 64 instead of 32):
loadfix -32 wc2.exe %1 %2 %3 %4
Now save the edited wc2.bat file and exicute this file from DosBox. The result should be that the edited wc2.bat file loads audio and everything else and then opens wc2.exe with loadfix.
Also, if you happen to use D-fend (as I do) you will have to uncheck the loadfix checkbox in the profile you have created for wing commander 2. If you leave it checked then it will load dosbox, mount the drives, and then exicute:
loadfix -32 C:\(fake cdrom path)\wc2.bat
That's no good.