> ## Documentation Index
> Fetch the complete documentation index at: https://comfytv.org/llms.txt
> Use this file to discover all available pages before exploring further.
# Muse Reverb (FDN)
> An algorithmic feedback-delay-network reverb with fine control over decay, tone, room size, and stereo spread.
## What this node does
**Muse Reverb (FDN)** adds artificial reverberation using a Feedback Delay Network — a bank of delay lines with feedback that produces a dense, natural-sounding tail without needing an impulse response. You control reverb time, room scale, pre-delay, the balance of dry/early-reflection/late energy, frequency-dependent decay, modulation, and stereo width.
It takes a `COMFYTV_AUDIO` snapshot (or a `COMFYTV_VIDEO`, whose audio track is used) and outputs processed `COMFYTV_AUDIO`. It has a ▶ **Run**. A source is required.
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
* Add hall, room, or chamber ambience to dry recordings without hunting for an IR.
* Sit a vocal or instrument in a defined space with controllable size and decay.
* Sculpt the reverb tone by making highs decay faster than lows (or vice versa).
## Parameters
### reverb\_time\_ms
Overall decay time (RT) in ms, **100–10000** (default **2200**). Longer = bigger, more sustained space.
### room\_scale
Size scaling of the delay network, **0.5–4.0** (default **0.8**). Larger values spread the reflections out for a bigger room feel.
### predelay\_ms
Gap before the reverb begins, in ms, **0–500** (default **10**). Adds a sense of distance from the walls and keeps the dry signal clear.
### Levels
* **dry\_db** — dry (unprocessed) level, **-60 to +6 dB** (default **0**).
* **late\_db** — late reverberation level, **-60 to +6 dB** (default **-14**).
* **er\_db** — early-reflections level, **-60 to +6 dB** (default **-14**).
### Frequency-dependent decay
* **time\_low** — low-band decay scaling %, **50–200** (default **100**).
* **time\_high** — high-band decay scaling %, **50–200** (default **60**). Lower = brighter highs die faster (more natural).
* **xover\_low\_mid** — low/mid crossover Hz, **50–500** (default **400**).
* **xover\_mid\_high** — mid/high crossover Hz, **1000–10000** (default **4000**).
* **feedback\_top** — top-end damping frequency Hz, **500–20000** (default **8000**).
### Modulation & width
* **mod\_freq** — tail modulation rate Hz, **0–10** (default **1.0**).
* **mod\_amp** — modulation amount, **0.0–1.0** (default **0.2**). Adds subtle movement to avoid a static, metallic tail.
* **stereo\_spread** — stereo width %, **0–150** (default **100**).
### quality
Network size: `8` or `16` delay lines (default **16**). 16 is denser and smoother; 8 is faster.
## Outputs
| Output | Type | Meaning |
| --------- | --------------- | ------------------------------- |
| **audio** | `COMFYTV_AUDIO` | The reverberated audio snapshot |
## Tips
* Keep the highs decaying faster than the lows (**time\_high** below **time\_low**) for a natural room; equal values sound artificial.
* A little **mod\_amp** (\~0.2) stops long tails from ringing metallically.
* If the reverb muddies the mix, raise **predelay\_ms** or lower **late\_db** to keep the dry signal forward.
## Related nodes
* **Audio Convolve (IR)** — reverb from a real recorded space instead of an algorithm.
* **Audio Echo** — discrete echoes rather than a dense tail.
* **Audio EQ** — carve space for the reverb, or de-mud it after the fact.