Re: [fluid-dev] SoundFont exclusiveClass

[S. Christian Collins]

On 09/12/2016 08:13 AM, Dan Eble wrote:
> > > Say I have an instrument with a release time of 2 seconds.  Fluidsynth sounds 
> > > as if it is playing the sound at constant volume for 2 seconds after the end of 
> > > the note, then stopping abruptly.  According to the SoundFont spec, the volume 
> > > should instead decrease linearly to zero.
> > I have been working with FluidSynth for years and have never encountered this 
> > issue. Do you have a SoundFont that exhibits this problem that you could share?
> Here’s a simplified version.  The instrument I’m having trouble with is 
> supposed to give the impression of the sympathetic resonance of a cello string 
> when another string is bowed.  It’s called “Vc, Bowed Symp. 4” in the attached 
> file.

The problem isn't the envelope, it's the excessive amount of filter Q 
you are using on that layer. What appears to be happening is that the 96 
dB of resonance amplifies the resonant frequency to a super-high level, 
which seems to be getting capped by a built-in limiter. Because the 
resonant level is so high, the limited audio level sounds flat. Since a 
voice at its quietest envelope point will receive 96 dB of attenuation 
according to the SF spec, the voice is essentially 100% amplified until 
it is cut off (which is why you hear a click).

So, if you reduce the filter Q level, you will begin to hear the proper 
release phase.

-~Chris