Hi Chris,
I have got much more successful results on straight EEEBUNTU / Ubuntu 8.10 (kernel 2.6.27-8-eeepc).
Did you see my update to the FAQ see:
http://pianobooster.sourceforge.net/faq.html#how-do-i-hear-the-sound-on-linux-ubuntuthis is the command line that I am using to start fluidsynth
./fluidsynth -C 0 -R 0 -c 6 -z 128 -r 22050 -l -a alsa -o audio.alsa.device=plughw:0 -o midi.alsa_seq.id=fs /usr/share/sounds/sf2/FluidR3_GM.sf2 /usr/share/sounds/sf2/FluidR3_GS.sf2
Can you try the above and let me know how it works for you. It is MUCH better than XP which is unusable. I am not using jack.
I have added -c 6 -z 128 from the FAQ which reduce the latency a bit more as the -r 22050 doubles the latency.
did you see this link?
http://fluidsynth.resonance.org/trac/wiki/LowLatencythe key flags are -o audio.alsa.device=plughw:0 which by passes the Pulse Audio on Linux which is cause of a lot of the latency delay. (apparently you can just un-install Pulse Audio)
with a real time kernal you should get very low latency try changing -c 6 to -c 2.
For windows users there is a possibility I will integrate fluidsynth with the PB (It is easy to change the code if anybody wants to give it a go please post to the dev forum).
Also for windows users try the Latency Fix see
http://pianobooster.sourceforge.net/faq.htmlLouis