Thank you all for the great help and precious advice you provide! :)
@JoeGBradford: "If the soft synth is multi timbral you should be able to do it by installing the synth as a First Audio Output track"
OK, I have this setting indeed, and I've tried this, but it's still the same: all tracks play the same patch, although I seem to have the ability to choose a different channel for each. I wonder how I will know for sure whether a soft synth is multitimbral or not...? I mean, will I see something specific in the settings, panels or whatever?
@LordElpus: "The TTS-1 Soft Synth may be what you need."
OK, this might be perfect, indeed. The sounds seem great (at least, enough for my all-purpose, generic use).
If I refer to:
http://www.cakewalk.com/P...tor/feature.aspx/TTS-1 I understand that TTS-1 comes as a feature of "Music Creator 6"...?
@RobertB: "You might want to consider downloading MC6. MC6 itself is virtually identical to X1LE"
"MC6" = Music Creator 6 I presume? Music Creator is an enhanced version of Sonar X1 LE, right? So I could upgrade from Sonar to Music Creator 6? I'm sorry to ask, but I get a bit confused with all these software names...
@57Gregy: "And if you do find yourself running out of synth space, you can always Bounce the synth to audio, freeing up that synth to be used for another track."
I'm not sure exactly what you mean by this. Does that mean that I'd completely convert the MIDI/synth track to an audio track, so that I somehow freeze the track and get rid of all MIDI events to replace them with audio data? If yes, this is something I'd rather not do, because MIDI tracks are so convenient (lightweight, staff view, etc.). But maybe "bouncing" is a completely different process – and you can see how much I still have to learn about modern DAWs...
@RobertB: "Can you tell us exactly which synth(s) you are trying to work with? If you can provide a screen shot, that would be an immense help, as it allows us to see what you see."
I've tried with various soft synths, including Cakewalk Sound Center featured in Sonar X1 LE. I've also tested Acoustica Instruments, since it seemed to be the best GM sound bank I could get my hands on, as a VST plugin. But I couldn't figure out how to use one instance as a multitimbral synth, so I used as many instances as I could, until I reached the limit. I know this soft synth is featured as the default sound bank in a sequencer called Mixcraft, and it allows playback of GM MIDI files.
Anyway, thank you again for your help. If all it takes to solve my issue is get TTS-1 by purchasing
Music Creator 6 (€40) as I understand, then I think I will follow your advice.