Channel matrix

• Utility
• Since 0.2.0
• channels
• routing
• mix
• multichannel

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The Channel matrix routes input channels to output channels using a list of explicit routes, each with its own gain.

What it does#

The output width is declared on the node. Each route names a one-based input channel, a one-based output channel and a gain from -8 to 8. A route copies that input lane into that output lane at the gain. Several routes to one output add together, without normalization. Output channels with no route are silent, and an empty list of routes outputs silence. A route that points outside the declared bundles is rejected. Up to 256 routes are allowed. The node has no parameters; its width and routes are edited in the Channels section of its Properties.

When to use it#

Use it to downmix, swap or duplicate channels, or to mix a bundle down to a smaller one. For simple extraction use Select channels; for simple joining use Combine channels.

Ports#

Parameters#

This node has no numeric parameters.

This node has no parameters. Its routes are configuration on the node.

Tips#

• Negative gains invert polarity.
• A mono to stereo spread is a matrix with two routes from channel 1, one to each output.
• Routes are not normalized, so downmixing several loud channels can raise the level; use a gain below 1 on each route.

See also#

Select channels, Combine channels, Mixer, Multichannel audio.

Help patches

Each help patch is an ordinary Toy that teaches one idea. The diagram shows the Patch; the preview shows its Frame. Open it in TuneToys to play and edit it.

1. Route channels with a matrix

beginner Teaches: multichannel

Two channels routed into one output with explicit gains.

Connections as text

• Oscillator “left” audio output connected to Combine channels a input
• Oscillator “right” audio output connected to Combine channels b input
• Combine channels audio output connected to Channel matrix audio input
• Channel matrix audio output connected to Patch outputs audio input

• Each route copies one input channel to one output channel with a gain. Routes to the same output add.
• Channel 2 is routed at half gain, so it sits under channel 1.

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2. Swap channels and split to two outputs

intermediate Teaches: multichannel

A two-by-two matrix that swaps channels and shares one input.

Connections as text

• Oscillator “left” audio output connected to Combine channels a input
• Oscillator “right” audio output connected to Combine channels b input
• Combine channels audio output connected to Channel matrix audio input
• Channel matrix audio output connected to Patch outputs audio input

• Routes 1 to 2 and 2 to 1 swap the channels. The extra 1 to 1 route leaks some of channel 1 back.
• Destinations with no route are silent. An empty route list outputs silence.

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Related nodes

• Select channels Extract a contiguous channel range. Use several selectors to split a bundle.
• Combine channels Concatenate two audio buses, preserving every channel without mixing.
• Mixer Sum up to 32 channels, each with gain, pan, mute and solo, into one mix with a master level. Plug a cable in to add a channel.