One of the default modulators required by the SF2 spec is the "MIDI Note-On Velocity to Filter Cutoff", cf. section 8.4.2. Implementation details of this particular modulator are not quite consistent in the specs. That's why fluidsynth does not implement this modulator. If however fluidsynth had implemented this modulator (according to 2.01 spec), the modulator listed by your instrument would cancel this modulator entirely. But as it's not implemented, it's safe to remove it.
However I cant explain the volume spikes. Perhaps jjc can help out. Also I just noticed we already have a CC2 modulator implemented in fluidsynth. You simply need to 'setbreathmode' via the shell to activate it, cf. section 3.4.5: https://github.com/FluidSynth/fluidsynth/raw/master/doc/polymono/FluidPolyMono-0004.pdf Tom _______________________________________________ fluid-dev mailing list fluid-dev@nongnu.org https://lists.nongnu.org/mailman/listinfo/fluid-dev
