Routing and Buses
Routing is the path a signal follows through your session. A bus combines signals or carries them to another destination. Knowing that path helps you control several tracks together, share effects and find the point where a signal stops reaching the output.
- Trace the path
- distinguish insert from send
- check the destination
Where you run into this
- Mixing
- Recording
- Monitor mixes
What is the simplest signal path?
For an audio track, a simple route is source, track processing, track level and pan, then the main output. A software instrument first turns note data into audio before that audio continues through the route.
A group bus adds another stage. Kick, snare and hi-hat can each feed a drum bus, which then feeds the main output. The exact position of processing and send tap points depends on the DAW and its settings.
Insert, send and group: what is the difference?
- Insert
Processing placed in the track's path. The signal passes through it before continuing. EQ on a vocal track is a common example.
- Send and return
A branch sends some signal to another path, often an effect return. The original can continue separately, allowing a dry source and reverb to be mixed together.
- Group bus
Several track outputs feed a shared audio channel. Moving that bus's fader changes the combined signal, and processing there hears the combined input.
Trace a vocal with shared reverb
| Path | Route | What reaches the main output? |
|---|---|---|
| Direct vocal | Vocal track to main output | The vocal, including any processing already on its track |
| Reverb branch | Vocal send to reverb return to main output | The reverb signal |
| Another source | Guitar send to the same reverb return | Reverb generated from that guitar too |
For this conventional parallel setup, set the reverb plugin's output to wet only. Otherwise, the return may add another copy of the direct signal, changing the balance. Depending on processing and latency, parallel copies can also change tone.
Should the send be pre-fader or post-fader?
A post-fader send follows the source track's fader. Lowering the vocal also reduces the signal feeding its reverb, which is useful when you want them to move together.
A pre-fader send takes its signal before that fader. It can support an independent monitor mix or an effect that remains when the direct track is lowered. Mute and solo behavior varies by routing design, so test it in your DAW. Mixing: Space shows what a reverb or delay on a send does to the mix.
What does a group bus let me do?
After balancing kick, snare and hi-hat against each other, route them to a drum bus. You can then lower the whole kit without readjusting three separate faders.
A compressor on that bus responds to the summed drums. That is a different operation from applying a compressor to each track. A loud kick can influence the gain reduction applied to the whole group, so listen to the other drums too.
Why did the track become louder after routing?
Check for an unintended second path. A signal may be going directly to the main output and also reaching it through a send or parallel track.
Parallel paths can be intentional, but label them clearly. To diagnose an unexpected change, mute one destination at a time and follow the meters. Restore the intended paths before judging the mix balance.
Build a drum group
- Name the source tracksUse separate kick, snare and hi-hat tracks in your DAW.
- Create the group destinationRoute their main outputs to a drum bus that feeds the main output.
- Check the shared faderLower the bus and confirm that all three drum parts become quieter together.
- Test one effect branchSend the snare to a wet reverb return. Compare the dry snare, the return and both together.
- Trace the metersConfirm where each signal appears, including whether the return feeds the drum bus or goes directly to the main output.
What should I check when I hear nothing?
Start at the source and follow the meters toward the output. If the track meter moves but its bus meter does not, check that output assignment. If the bus moves but the main output does not, inspect the bus destination and mute state.
For MIDI, first confirm that note data reaches an instrument. A MIDI meter indicates instructions, not necessarily an audio signal. DAW Basics covers that distinction.
Is every folder a bus?
No. A folder may only organize tracks, or it may also sum their audio. A VCA-style control typically changes other channel levels without carrying their audio itself.
Check the signal route rather than relying on the name or visual grouping. If no audio passes through a control, placing audio processing there is a different question from controlling the channels it represents.