The sound font used by the system is always "/boot/system/data/synth/big_synth.sy".
For convenience this is actually linked to "/boot/common/data/synth/big_synth.sy", which itself is a link to the actual Soundfont file -- by default "TimGM6mb.sf2" in that same folder.

You can replace the default General Midi sound font with a better version by linking that "big_synth.sy" in common/data/synth to your alternative sound font. Some examples of  better quality (and bigger) sound fonts are:

fluid-soundfont-3.1 (141 MB, MIT license):
< http://ftp.de.debian.org/debian/pool/main/f/fluid-soundfont/fluid-soundfont_3.1.orig.tar.gz >

GeneralUser_GS: (29.83 MB, freely distributable for non-commercial use):
< http://www.schristiancollins.com/generaluser.php >
 download zip-file "FluidSynth-version 1.43" from the web page

A couple of other Haiku-accessible soundfonts are available at
< http://www.personalcopy.com/linuxfiles.htm > (The files must be downloaded via that page.)
