Every track so far went to the master at whatever level its patch happened to produce. A mixer is the layer where you decide, once, how loud each part is, where it sits, and what room it shares — and in Volta that layer is a declaration you can diff, not a saved snapshot of fader positions.
The first mixing decision comes before the mixer: you cannot balance what is not a separate channel. sound !"bd ~ sn bd, hh*8" is one track with two layers stacked by the comma — one fader for the kick and the hats together. Split it and each part gets its own strip.
mixer { kick = { level = -1.5dB }, hats = { level = -10dB, pan = -0.3, width = 1.4 } } is the desk. level takes dB or a plain linear ratio, pan is a balance in [-1, 1], width in [0, 2]. The layering rule: placement is authored in the patch (panTrack, jux), balance is mixed here.
bus hall = reverb 0.85 0.4 |> width 1.3 declares a shared aux — one reverb several channels feed, instead of four separate reverbs eating four times the CPU and smearing four different rooms over one arrangement. A strip reaches it with sends = { hall = -18dB } (or presends for pre-fader).
group drums = [kick, snare, hats] is a VCA over member strips: one number moves the whole kit. Groups never touch audio — the level folds into the members before it reaches the engine, which is why a group level seeds a macro but cannot ride one.
master = { level = -0.5dB, mono = false, refLevel = -18dB, inserts = [compress 0.12] } is the last stage: the whole-mix fader, the mono-fold check, and the delivery chain. Beware one sharp edge — a bare macro ident replaces a level rather than trimming it, so write level = (close * -6dB) when you want the knob to scale a balance you already dialled in.
The starting point#
The lesson opens with this song in the editor. Every edit recompiles and plays.
-- The mixer: four parts, one channel, no balance.
tempo = 122bpm
pad = patch {
source = saw (freq pitch) |> unison 5 20,
ampEnv = adsr 300ms 250ms 0.7 500ms,
cutoff = 1700Hz,
gain = vel * 0.35
}
kit = sound !"bd ~ sn bd, hh*8"
chord = play pad !"c3 eb3 g3"What to watch#
Split the kit and watch the spectrum separate into three moving humps instead of one; then pull the hats down 10 dB and see the top of the picture drop while the kick's low hump stays exactly where it was. That independence is the whole point of a channel.
Goals#
The workbench checks these as you work; the solution is there when you want it.
- Split the kit — four channels, not one
- Open the console and set a level
- Send two channels to one shared room
- Stretch: give the desk a master section
Make it yours#
Mix the four parts by ear with the transport running: get the kick and snare balanced first with everything else muted, then bring the hats in until they are just audible, then place them off-centre. Only after that touch the reverb sends.
Further reading#
Mixing tracks and buses in the reference.