[fluid-dev] My FluidSynth test results

[S. Christian Collins]

Here are the results of my tests of FluidSynth 1.1.6 RC:

1) SoundFont compatibility: Proper rendering of modulators, etc

Result: It's as good as ever.  I have yet to come across a SoundFont synth that handles the SoundFont 2.1 parameters and modulators better than FluidSynth.  In some cases it even surpasses the Audigy!

2) Voice stealing logic

Result: I can think of a few improvements to the voice stealing logic, but nothing is broken.  I'll share the improvement ideas at a later time.

3) Reverb and chorus

Result: It works, but the default values are not that great, IMO.  I spent a lot of time playing around with the reverb and chorus values, and I believe the following sounds considerably better:

Reverb:

• Room: 0.61
• Damp: 0.23
• Width: 0.76
• Level: 0.57

Chorus:

• N: 3
• Level: 1.2
• Speed: 0.3
• Depth: 8

FluidSynth's default reverb is too confined, so my settings give the music a better sense of space.  The main problem with Fluidsynth's reverb engine is that it has a bit of a metallic sound, causing spikes in annoying parts of the frequency range.  I would normally allow for more reverb to be present at CC91=127, but with this reverb, I feel it's best to mix it a bit lower.  Unfortunately, as far as sound quality is concerned, I consider the reverb to be the weakest component of Fluidsynth.

I also noticed that the reverb presets defined in fluid_synth.c line 144 appear to have been designed for testing the parameters of the reverb engine, but they are not very useful musically.  I would be happy to create new presets to replace these ("Large Hall", "Small Hall", "Room", etc.).

The default chorus values are too brash and have been replaced with warmer settings.

I have attached a couple of MIDI files to this e-mail for testing these reverb settings:

• S_Christian_Collins--March_1_in_D_major.mid - this was my first orchestral composition back when I was in high school.  This MIDI file uses lots of reverb.
• S_Christian_Collins--The_Hybrid_Collage.mid - This is a collage of a bunch of unfinished songs and was written to demonstrate a lot of MIDI instruments and effects.

The Hybrid Collage was written using GeneralUser GS.  You can compare FluidSynth's playback to the original Audigy version here (see under "Examples").  Fluidsynth is able to come decently close using my new reverb and chorus values; the Audigy just has a much better reverb, though.  The main difference you will hear with FluidSynth is the missing filter wah-wah in the electric guitar in the middle of the song.  I'm guessing FluidSynth must not be compatible with the Sound Blaster NRPNs that control the filter.

Anyway, those are the results of my tests.  Please let me know if you want me to do anything for this release or a later one.

God Bless,
-~Chris

S_Christian_Collins--March_1_in_D_major.mid
Description: MIDI audio

S_Christian_Collins--The_Hybrid_Collage.mid
Description: MIDI audio