Hello Bernat,
Sorry it took me so long to answer your question. Unfortunately I'm not
sure currently what exactly causes this issue and I haven't yet really
put any time into figuring it out yet either. As you mentioned though,
it does indeed seem like its a distortion that occurs even though the
sound card output is not maxed, which would indicate internal distortion
of some sort. I suspect it might have to do with reverb or chorus (try
turning them off) or perhaps with the volume attenuation of samples and
how they are mixed.
I've added a ticket for this issue here:
http://fluidsynth.resonance.org/trac/ticket/13
I'm currently working on getting Swami 2.0 released after which I'll be
putting some more time into FluidSynth.
Thanks for reporting this issue and your other findings.
Josh
On Mon, 2008-03-17 at 02:03 +0100, Bernat Arlandis i Mañó wrote:
I've done some more investigation. Connecting Fluidsynth output to
Rezound I've saved the waveforms with lower gain (no distortion) and
higher gain (with distortion). I've always avoided clipping that occurs
at very high gain levels. I've used piano soundfonts, mainly the
"Microfont piano collection (6MB)" soundfont.
I've compared the same sound with distortion and without distortion and
I've discovered that the distortion is caused by the gain changes alone,
but I don't know why some samples don't get distorted. For example, the
"triangle simple" preset in Vintage Dreams soundfont can be maxed with
gain 140 without any distortion before it starts clipping.
I'm not an audio expert and I certainly missing something. I've tried to
ensure soundcard and speakers are not the problem. I can supply the wave
files tested. Please, could someone throw some light?
Thank you.