MORE than 16 MIDI Channels

There is a limit to 16 MIDI channels per MIDI port. Hanging off my humble little Powerbook, I have at least 10 independent MIDI outs, for 160 MIDI channels (and that's only for external devices - internal devices such as virtual instruments aren't really dependent on MIDI channels.

So are you talking about needing more that 16 channels of MIDI data going to external MIDI instruments (in which case, you need more MIDI ports on your interface), or internal softsynths etc where MIDI channels are irrelevant..?

No don't bother about the Midi Channels of your Software Instruments. As Bee Jay said, each Plug In has 16 Midi channels available (check in the Inspector) but you only use one of them if you don't use multitimbral instances of e.g. Kontakt 3. If you do use multitimbral instances of Kontakt then you would have 16 Channels available per each multi-instance of Kontakt.

Yep, what SC said.

Basically, you can think of it like each audio instrument track has an internal independent MIDI "port", as the MIDI (up to 16 channels) will be sent to that audio instrument exclusively, and independently from any other audio (or MIDI) instrument tracks.

Normally, for mono-timbral instruments, it doesn't matter what MIDI channel events are on, they will all be sent to the synth and the synth will play the notes. You can re-channelise on the instrument object if necessary, but for the most part it's not necessary.

For multi-timbral audio instruments, you again have 16 MIDI channels per instrument, and in this case, the MIDI does matter, as it's the MIDI channel will determines which parts the instrument plays.

So, basically, you can think of it like each audio instrument object has it's own internal independent MIDI port of up to 16 channels. MIDI data on a track assigned to audio instrument 1 does not go anywhere near MIDI data assigned to audio instrument 2 - they are independent.

Does that help?

Well the Midichannels for Audio tracks become relevant when you use an external Controller/Mixer to control them. E.g. I have my Tascam DM24 Mixer setup to control the Volume faders in Logic. Fader 1 is transmitting on Midi Channel 1 - fader 2 on Channel 2 and so on.
So if I want to write more than one volume curve at once Logic detects the different incoming Midi Channels and assigns them to the Audio tracks with the corresponding Midi Channels.

Yes - an audio object is an environment object like any other environment object, and can therefore have MIDI sent to it.

In this instance, the audio object itself responds to MIDI commands, notably controllers for pan and volume - this was the old way of MIDI remote controlling the mixer (before the whole control surface side of Logic was developed).