[fluid-dev] Gain distortion with many soundfonts

[Bernat Arlandis i Mañó]

Hi.

I've been playing with fluidsynth (thru qsynth) and tried a lot of
soundfonts, mainly free piano soundfonts, a lot of them. They all make
static noise when master gain is not very very low. I've checked there's
no soundcard clipping, lowering the mixer output doesn't help at all.
Watching thru the oscilloscope dssi plugin I can see the output isn't
too high. I have to set up a very low gain (10) then put my speakers'
volume level insanely high to hear what I'm playing.

Curiously, when playing with the vintage dreams soundfont included in
the tarball there's no such noise, even with the highest gains it sounds
very clear and good.

I've come across this in the mailing list
(http://www.mail-archive.com/address@hidden/msg00378.html):

"Current FluidSynth annoyances for me:
- Gain control is rather hard to get right (output is often clipping)
- Output clips even when sound card output isn't maxed (internal
clipping?)"

The oscilloscope doesn't seem to show any clipping, although it could
be. It rather seems some amplification distortion when output volume is
above some threshold. The strange thing is that it doesn't happen for
all soundfonts.

I'm running v1.0.8 in Debian SID arch AMD64. I'd like to help sort this
out as I'm using fluidsynth a lot and it's a great softsynth.

Thank you.
Best regards.

--
Bernat Arlandis i Mañó