Timidity vs Qsynth - Memory usage

[fernandoamartin]

Hi.
I write music in rosegarden and use timidity or qsynth for midi output. However I have some soundfonts that don't work right in timidity so I have to use qsynth more often.
I've noticed that no matter how many soundfonts are indicated in timidity.cfg and how large they are when playing music timidity seems to use only the instruments and presets needed by that music, making timidity very fast to start.
On the other hand qsynth, right at its startup, seem to read and/or load all the soundfonts that are indicated at its config. The result is that if I'm going to use soundfonts with a large size qsynth delays to start and depending on their size all my computer becomes slow while I'm using it. In qsynth itself I haven't found any option about it but since qsynth is a front-end to fluidsynth I wonder if it's possible to change this behavior in fluidsynth configuration.
Is there any way to make fluidsynth read and load only the instruments and presets that are being played at a given moment like timidity does?

[bluebell]

I used fluidsynth-dssi as a synth module in Rosegarden. Works fine.

[fernandoamartin]

I used fluidsynth-dssi as a synth module in Rosegarden. Works fine.

I tried it sometimes but I experiment with several instruments and use program changes at the same track, so the dssi is not a good option for me.