Ableton/Live/UG/17 Routing and IO/05 Internal Routings
- Tracks can feed each other in two ways:
- Track A sends to B through A's Output Type. Suits many-to-one setups such as submixes or several MIDI tracks sharing an instrument. Soloing B still plays everything feeding it.
- Track B takes from A through B's Input Type. Suits one-to-many setups such as layering, where several tracks tap one source.
- When a track's Audio From is another track, the Input Channel chooser picks where the signal is tapped:
- Pre FX — straight from the track, before its devices and mixer.
- Post FX — after the devices, before the mixer.
- Post Mixer — the track's final output after volume and pan.
- Soloing the tapping track lets you hear the tapped track at Pre FX and Post FX, but not at Post Mixer.
17.5.1.1 Routing Points in Racks
- Every chain of an Instrument or Effect Rack, and every return chain of a Drum Rack, offers the same three tap points, listed as
Rack | Chain | Pre FX, Post FX or Post Mixer. Post Mixer is the chain's output just before the chains are summed. 
- Soloing a track that taps a chain still lets you hear that point.
17.5.2.1 Post-Effects Recording
- To record a guitar already processed by a gate or amp model, put the effects on a "Guitar" track with Monitor set to In, and record on other tracks whose input is the Guitar track at Post FX (or Post Mixer to include its level and pan). Set those tracks' Monitor to Off.
17.5.2.2 Recording MIDI as Audio
- When a complex instrument turns one note into something closer to a passage, record its audio: one MIDI track hosts the instrument, and an audio track taking input from it records the result.
17.5.2.3 Creating Submixes
- Route several drum tracks to one submix audio track that goes to Main, so one fader controls the whole kit.
- A Group Track sets up the same routing automatically and can fold its tracks away.
- Or set each track's Output Type to Sends Only and use a send, so a return track acts as the submix.
17.5.2.4 Several MIDI Tracks Playing the Same Instrument
- Point a second MIDI track's Output Type at the instrument track, and choose the instrument itself (not Track In) as Output Channel. Both tracks then play one instrument, so sound changes affect both.
- To mute each part separately, move the original clips to a third track and leave the instrument alone on its track, with Input Type set to No Input so it has no Arm button.
17.5.2.5 Tapping Individual Outs From an Instrument
- Impulse offers each of its eight sample slots as a source for other tracks. An audio track whose input is the Impulse track can choose one slot, which takes that slot out of Impulse's own mix for separate effects. Most plug-ins don't remove the tapped output this way.
17.5.2.6 Using Multi-Timbral Plug-In Instruments
- A multi-timbral instrument plays a different part on each MIDI channel. Extra MIDI tracks feed its parts by pointing Output Type at the instrument's track and Output Channel at each part's channel; audio tracks tap its individual outputs.
- External Instrument devices on other MIDI tracks can do both at once: set MIDI To to the instrument's track and channel, and Audio From to one of its auxiliary outputs. Several can share one track inside a Rack. The instrument's main outputs stay on its own track.
17.5.2.7 Feeding Sidechain Inputs
- A vocoder on a strings track needs a speech signal at its sidechain input: create a "Speech" track whose Output Type is the strings track and whose Output Channel is the vocoder's sidechain. Vocoder plug-ins with their own carrier synth go on a MIDI track and are fed the same way.
- Many of Live's built-in devices have their own sidechain choosers, so they don't need this.
17.5.2.8 Layering Instruments
- To double a strings part with brass, add a MIDI track with a brass instrument whose Input Type taps the strings track at Post FX. MIDI from another track is tapped after its MIDI effects and just before its instrument, so the brass gets the same notes.
