> ## Documentation Index
> Fetch the complete documentation index at: https://comfytv.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Audio Stereo

> Reshape the stereo field — widen, narrow, cross-feed, Haas-delay, balance, collapse to mono, or swap channels.

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  <img src="https://mintcdn.com/comfytv/dMkMxJDZdIo4YzAU/images/nodes/_placeholder.svg?fit=max&auto=format&n=dMkMxJDZdIo4YzAU&q=85&s=b54171099e5b02d4313fe581171ebbcc" alt="Audio Stereo" width="800" height="450" data-path="images/nodes/_placeholder.svg" />
</Frame>

## What this node does

**Audio Stereo** applies one of seven stereo-field operations to a track, using the matching FFmpeg filters (`stereowiden`, `extrastereo`, `crossfeed`, `haas`, `stereotools`, `pan`). You pick a **mode** and adjust only the parameters that belong to it.

It takes a `COMFYTV_AUDIO` snapshot (or a `COMFYTV_VIDEO`, whose audio track is used) and outputs processed `COMFYTV_AUDIO` plus an `fx_spec`. It has a ▶ **Run** (FFmpeg does the work). If no source is wired, it emits just the `fx_spec` for chaining.

To feed native ComfyUI `AUDIO` in or out, insert a **Bridge** — see [bridges.md](https://github.com/jtydhr88/ComfyTV/blob/main/docs/bridges.md).

## When to use it

* Widen a flat stereo mix so it fills the speakers.
* Tame overly-wide material with crossfeed for comfortable headphone listening.
* Collapse to mono to check phase, or swap L/R to fix a reversed recording.

## Parameters

### mode

Which operation to apply. Options: `widen` (default), `extrastereo`, `crossfeed`, `haas`, `balance`, `mono`, `swap`. `mono` and `swap` have no extra parameters.

### Widen (`sw_*`)

* **sw\_delay** — delay in ms, **1–100** (default **20**).
* **sw\_feedback** — feedback amount, **0.0–0.9** (default **0.3**).
* **sw\_crossfeed** — cross-feed amount, **0.0–0.8** (default **0.3**).
* **sw\_drymix** — dry mix, **0.0–1.0** (default **0.8**).

### Extra Stereo

* **es\_m** — stereo expansion factor, **-10.0 to 10.0** (default **2.5**). Values above 1 widen; below 0 invert.

### Crossfeed

* **cf\_strength** — crossfeed strength, **0.0–1.0** (default **0.2**).
* **cf\_range** — soundstage range, **0.0–1.0** (default **0.5**).

### Haas

* **haas\_side\_gain** — side channel gain, **0.06–12.0** (default **1.0**).
* **haas\_left\_delay** — left delay in ms, **0.0–40.0** (default **2.05**).
* **haas\_right\_delay** — right delay in ms, **0.0–40.0** (default **2.12**).

### Balance

* **balance** — L/R balance, **-1.0 to 1.0** (default **0.0**), fed to `stereotools` `balance_out`.

## Outputs

| Output       | Type             | Meaning                                             |
| ------------ | ---------------- | --------------------------------------------------- |
| **audio**    | `COMFYTV_AUDIO`  | The processed audio snapshot                        |
| **fx\_spec** | `COMFYTV_FXSPEC` | The effect as a spec, for chaining into an FX Chain |

## Tips

* Only the parameters for the selected **mode** matter — the rest are inert.
* Very wide `extrastereo` values can cause mono-compatibility problems; check in `mono` mode before committing.
* `swap` and `mono` are pure channel-math with no tunable knobs — instant fixes.

## Related nodes

* **Audio Modulation** — chorus/flanger can also add perceived width.
* **Audio Analyze** — check loudness/levels after reshaping the field.
* **FX Chain** — renders multiple `fx_spec` steps (including this one) in a single pass.