> ## Documentation Index
> Fetch the complete documentation index at: https://rendobar.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
> ## Agent Instructions
> Keep the API key in an env var (RENDOBAR_API_KEY), never in chat or committed code.
> Job types change, so fetch the live catalog from GET https://api.rendobar.com/jobs/types rather than relying on memory.
> The full integration prompt for coding agents is at https://rendobar.com/prompts/integrate.md.
# Audio levels and effects
> Set levels and fades, clean up a voice recording, and draw sound onto the picture as a waveform or bars.
Sound is a clip like any other, and a `volume` on any clip that has audio sets its level. Fades sit next to it. Everything past that is an effect on the `sound` medium, and the same effect list works on a clip or on a whole track.
```json theme={null}
{
"asset": { "type": "audio", "src": "https://example.com/music.mp3", "volume": 0.35, "fadeIn": 1.5, "fadeOut": 2 },
"length": "end"
}
```
## Levels that work
`volume` is linear gain. With speech at 1.0: music under speech 0.10 to 0.12, music alone 0.35 to 0.5, sound effects 0.25 to 0.32. Fade music in over 1 to 2 seconds and out over 3 to 5, ending on the last frame. To duck music under speech, keep one music clip and put keyframes on its `volume`: 0.4 before the first word, 0.11 under the speech, back to 0.4 after it. `fadeIn` and `fadeOut` work alongside those keyframes.
## Cleaning up a recording
`loudness` brings a quiet recording to a streaming target. `voiceDenoise` removes steady background noise from under speech. `gate` closes the microphone between phrases, `highPass` cuts rumble below the voice, `eq` shapes it, and `compressor` evens out loud and quiet words.
## Shaping and colour
`reverb`, `echo`, `pitch`, `lowPass` and `limiter`. A limiter makes music louder without letting peaks clip.
## Sound drawn on the picture
`visualizer` draws the sound onto the frame for an audiogram or a podcast clip, as a waveform, bars or a level meter.
Every sound effect and its parameters are in the [effect reference](/docs/docs/jobs/compose/reference/effects).
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