Audio Mix
A mixer for a layer's Output: a dB fader for every connected audio input, a master, and an A/B crossfader.
Category: Composite Menu path: Composite > Audio Mix
Ports
| Port | Type | Direction | Description |
|---|---|---|---|
inputs | audio | input (multi) | Any number of audio streams: Audio Source outputs, Comp Source Audio outputs, or other Audio Mix nodes. |
out | audio | output | The mix. Wire it into the Output node's Audio input. |
Parameters
The Properties panel shows this node as a mixer rather than a list of fields. Every control below is a keyframeable param (the diamond at the left of each row adds or removes a keyframe at the playhead).
| Param | Type | Default | Description |
|---|---|---|---|
crossfade (Position) | scalar −1…+1 | 0 (Center) | The crossfader. −1 plays only side A, +1 only side B, 0 is neutral: both sides at their faders. Shown as 36% A, Center, 100% B. |
level (Master › Level) | scalar, dB | 0.0 dB | Master level over the mix. |
level:<n> (per input) | scalar, dB | 0.0 dB | The input's fader. One per connected input, in the Inputs rows. |
side:<n> (per input) | A / - / B | first two inputs A and B, then - | Which side of the crossfader the input rides, or none. The small A – B control on each row. |
How It Works
Each input passes through its own fader, then its crossfader side, then everything is summed and scaled by the master. All levels are in decibels: 0 dB leaves a signal unchanged, −6 dB is about half, +12 dB is the ceiling, and −60 dB is the floor, shown as −∞ and truly silent. Faders have a mixing taper: three quarters of the travel covers −12 to +12 dB, the last stretch falls to −∞, and a notch marks 0 dB. Double-click any fader to return it to 0 dB; type -inf or off in a value field for silence.
The crossfader blends everything on side A against everything on side B. Center is neutral, so assigning an input changes nothing until the slider moves; pushing toward A fades the B side out on a cosine curve, and the reverse. Inputs set to – ignore it. That is how it scales past two inputs: put two beds on A and B and leave the voice-over on –, or group three stems on A against two on B and move one slider. The first two inputs you connect come in as A and B, so a two-input node crossfades immediately; a third arrives unassigned.
Per-input settings follow their input: reorder the Inputs list and the faders move with the rows; disconnect an input and its settings disappear; copy or duplicate the node and they come along. Pan is not on this node: the layer's Output pans the mixed result, the same way a Merge leaves opacity to the layers above it. A source's own Level (Audio Source) still applies before it reaches the mix.
The mix is heard in live playback and RAM preview and lands in every audio-bearing export.
Usage Examples
Basic: Music under a voice-over on one layer
- Add two Audio Source nodes pointing at the two files
- Add an Audio Mix and connect both Audio Source outputs to its Inputs
- Connect Audio Mix → Output's Audio input
- Pull the music's fader to −12 dB and keyframe it lower under the voice
Crossfade between two beds
Wire two Audio Sources into an Audio Mix; they arrive as A and B. Keyframe Position from 100% A to 100% B over the transition.
Two nested comps, one layer
Two Comp Source nodes side by side (their images merged for the picture) can share one Output's audio: wire both Audio outputs into an Audio Mix and balance them with their faders.
Tips
- An Audio Mix with nothing connected is silent and does not make the layer count as audible for export.
- Audio Mix nodes can feed other Audio Mix nodes for sub-groups; each stage has its own master.
- Value fields behave like every other param: drag left/right to scrub (Shift ×10, Ctrl ×0.1, Alt ×0.01), arrow keys step 0.1 dB, type a number or an expression.
- The timeline draws no waveform for a mixed layer yet.
- Keep one sound per layer when you want separate Pan or Mute controls; use Audio Mix when several sounds should ride one layer's clip and Output.
Related Nodes
- AudioSource — the file input each stream starts from
- CompSource — a nested composition's audio as one stream
- Merge — the picture-side equivalent for stacking images