LC Audio Channel 🎚️

Sometimes you just want one side of a stereo track. A voice panned hard left, a drum part sitting in the right channel, a backing element you'd rather drop entirely. LC Audio Channel is the two-second fix for that: it takes one AUDIO wire and hands you left and right as two separate AUDIO outputs, so you can keep one, mute the other, or process each side differently and recombine later.

It looks unglamorous next to the AI stem splitters, and that's the point. The author's own description flags that it's the "old channel-split backend" that LC Audio Separate deliberately kept around - so when you only need L/R, you grab this instead of loading a Hybrid Demucs model to separate an entire mix. L/R splitting is a pure arithmetic cut; stem separation is an inference job. They are not the same tool, and you should not pay the second one's cost for the first one's result.

How it works

Comfy audio arrives as {"waveform": tensor, "sample_rate": int} with the waveform shaped channels × samples. This node splits on the channel axis: channel 0 becomes left, channel 1 becomes right. What it does with mono is the detail worth knowing - a mono file gets duplicated to both outputs, so whatever you wire downstream always has two channels to work with and your graph doesn't silently collapse to silence on one side.

The inputs and outputs that matter

There's exactly one input: audio. Everything else is the three outputs:

• left (AUDIO) - first channel, or the whole mono file duplicated.
• right (AUDIO) - second channel, or the mono file again.
• note (STRING) - a little status string telling you what actually happened: stereo L/R, mono duplicated, or no audio for an empty input. Handy as a canary if you're not sure what your upstream loader produced.

Wire the side you want onward - into a VAE-less audio path like LC Save Video's audio input, or into more LC audio nodes if you're chain-processing.

How to install it

LC Audio Channel ships in the ComfyUI_LC_AV_nodes pack (a small AV toolkit by lonecatone23, MIT licensed, companion to the image-side ComfyUI_LC123_nodes - keep the two folders separate, they share nothing). Install once for the whole family:

• ComfyUI Manager: search "LC Audio_Video" (or the repo title ComfyUI_LC_AV_nodes) and install.
• Manual: cd ComfyUI/custom_nodes && git clone https://github.com/lonecatone23/ComfyUI_LC_AV_nodes then restart.

Restart ComfyUI and the console should print [LC AV] total 16 nodes. No extra Python packages, no model downloads - this one only needs the torch/numpy that ComfyUI already runs on.

Where people get tripped up

The most common surprise is feeding this a file that looks stereo but is actually dual-mono - you get the same sound on both outputs and assume the split failed. That's correct behavior, and the note output will confirm it. If you're separating channels so you can build an instrumental or acapella, this node is not that: it separates sides, not sources. For actual stems (bass, drums, vocals), that's what LC Audio Separate in this same pack is for.