Focus Room Playlist Renderer

What it is for

You want one audio file that runs through several calm backgrounds — brown noise, then a rainy room, then soft rain — without abrupt cuts, and with a sound that suits your headphones or a small speaker. This tool builds that file. It takes a list of generated scenes, plays them one after another with crossfades, and runs the whole mix through a master chain: low cut, high cut, an eight-band equalizer, room reverb, stereo width, volume and a gentle limiter.

It is the server version of the Render playlist to WAV feature of the Focus Room app. For the same room and the same scene lengths both give the identical file. It only renders generated scenes: Soundscape Atlas worlds with real Wikimedia Commons recordings are refused, because those recordings are streamed in your browser, not on the server.

Worked example

Enter three lines in Scenes:

surf-like-swell 30
fireside 30
night-wind 30

Set Crossfade to 10 seconds, Master effects preset to Far away and Sample rate to 48 kHz. The tool answers: 3 scenes mixed into 70 seconds of stereo audio: peak -18.97 dBFS, RMS -36.54 dBFS.

Why 70 seconds and not 90? Each scene starts ten seconds before the previous one ends, so the timeline reads: Surf-like swell 0–30 s, Fireside 20–50 s, Night wind 40–70 s. The last scene also fades out over ten seconds instead of stopping dead. Limited samples is 0, so the limiter never touched the signal.

The Far away preset explains the low level: it cuts below 180 Hz and above 3.5 kHz, adds a concert hall at 120 %, narrows the stereo image to 70 % and lowers the volume by 3 dB. With the default example (brown noise, rainy study room and pink rain, 20 s each, 6 s crossfade, Warm) the file is 48 seconds long with a peak of -14 dBFS.

How to read the result

• File length is the real duration: the sum of the scenes minus the overlaps.
• Peak level and RMS level are measured after the master chain. Ambiences are meant to sit in the background, so an RMS around -30 dBFS is normal; raise it with a louder preset or by normalising the file elsewhere.
• Limited samples counts samples the soft limiter changed. Anything above zero means the mix was pushed hard.
• The Timeline table lists every scene with its start, end and fade lengths, and whether it is generated.
• The chart shows the combined frequency response of the cut filters and the eight EQ bands.

Tips and common mistakes

• A crossfade never takes more than half of a scene. With 8-second scenes and a 10-second crossfade you get 4-second fades.
• Paste a whole room into Focus Room to use its shuffle order, crossfade and master effects. Seconds per scene then shortens each scene, because rooms usually hold 25-minute scenes.
• The total is limited to 300 seconds on the server. The app renders up to 10 minutes on your own device.
• Write lengths as fireside 2 min if seconds feel awkward.
• Surf-like, coffee-shop-like and similar names describe filtered noise that imitates a sound. They are not recordings of those places.

FAQ

Is the crossfade really equal power?

Yes. The outgoing scene follows a cosine curve and the incoming one a sine curve, so the sum of their powers stays constant. Two unrelated ambiences therefore neither dip nor swell during the change.

Will the file loop seamlessly?

No. It is a playlist with a fade-out at the end. For a seamless single loop use the Soundscape ambience or noise generators.

Why was my room refused?

It contains a scene with Wikimedia Commons recordings, for example Night forest or Alpine brook. Render it in the Focus Room app, which loads the recordings in your browser.

Can I use the WAV commercially?

The scenes are synthesized from seeds by the usefulweb audio engine and contain no third-party recordings, so the file is yours to use.