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

# FLAC and LOW BANDWIDTH

> Lossless FLAC by default, Opus for slower connections, both inside IAMF

# FLAC and LOW BANDWIDTH

The plugin always sends IAMF (Immersive Audio Model and Formats, the open format behind Eclipsa Audio). The **LOW BANDWIDTH** button chooses the codec inside it. It is off by default, it is saved with your DAW session, and it is fixed while streaming.

| | LOW BANDWIDTH off | LOW BANDWIDTH on |
| - | - | - |
| Codec | FLAC, 24 bit | Opus |
| Quality | lossless | lossy |
| Bitrate | variable, about 0.81 Mbps a channel on music[^1] | 64 kbit/s a channel |
| Header line | **IAMF FLAC 24-BIT · LOSSLESS** | **IAMF OPUS · LOSSY · 64 KBPS/CH · N MBPS** |

Both are sent at 48 kHz. A session at another rate is resampled for the stream only, and the header says so (**44.1 kHz HOST, SENT AT 48 kHz**); your session's own audio is untouched.

## Lossless FLAC

FLAC is the default because the listener hears exactly the samples the plugin sent, at 24 bit. Its bitrate follows the material: a sparse click track or a single tone is far smaller than a dense mix, and a quiet room recording whose noise floor fills the low bits sits close to the top of its range. Plan your network for music, at about 1 Mbps a channel (see [Network](/remote/reference/network)).

## LOW BANDWIDTH (Opus)

LOW BANDWIDTH sends Opus at a fixed 64 kbit/s a channel, which is 0.77 Mbps for the twelve channels of 7.1.4 (twelve channels of FLAC at the music rate above come to about 9.7 Mbps). We provide it for listeners on mobile or congested connections, and for rehearsals and reviews of structure and timing.

The header line shows the stream's total Opus rate (**0.77 MBPS** at 7.1.4) so you can check it against a listener's connection before START.

## Switching between them

STOP, toggle LOW BANDWIDTH, and START again. Each START makes a new link, so send the new one. The listener page reads the codec from the stream itself, so listeners do nothing different for either.

## Cost

Relay is priced by channels, listeners and time for both codecs. See [Pricing](/remote/reference/pricing).

[^1]: Measured on music at 24 bit. FLAC is variable rate; tones, silence and sparse material use less.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.