on my PC I use a MIDI-keyboard with jackd and fluidsynth (with a soundfont) and I can get a decent piano-sound (my PC does not have an external sound-card but has one integrated into the mainboard).
The same setup on the Pi works in principle but the resuting sound (speakers connected via the 3.5mm cinch) is awful.
I have not seen this big quality discrepancy when playing mp3s or streams. Here the Pi does not sound that much worse than my PC but here it does (in general playback of media on the Pi is of acceptable quality).
I now would like to understand why that is and what I can do about it.
Would an external USB sound-card improve the situation? If so would a very cheap one (e.g. Daffodil US01) be enough?
Or could it be that the process of "rendering" a soundfont via fluidsynth hits some other limitation of the Pi so that an external card would change nothing?
Any other ideas on what I could try?