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Thaumic Cast

Advanced audio settings

The defaults suit most homes. This page is for when the sound cuts out, arrives late, or you simply want to know what the switches do. Settings live in two places: the extension’s Settings (how your browser captures and sends the audio) and the desktop app’s Settings (how the app hands it to the speakers).

In the extension: Audio

Section titled “In the extension: Audio”

Open the extension’s Settings, then Audio. A cast that is already playing keeps its settings; changes apply from the next cast.

Setting Default What it does When to change it
Quality Luxurious Four presets: Economical (the least network), Sensible, Luxurious (every bit; PCM, lossless) and Bespoke (every choice is yours). Settings shows what each one comes to in your browser. Choose Economical for Wi-Fi that is already doing its best. Economical also skips ahead when the connection falls behind, rather than letting the delay grow.
Codec, Bitrate, Channels, Sample rate PCM, stereo In Bespoke only: the format of the next tab cast. PCM goes out at the rate the browser captures it, usually 48 kHz. When you want a particular codec. If the browser will not encode the combination, Settings says so and a tab cast set to it will not start.
When the connection falls behind Let delay grow (up to a limit) In Bespoke, for a tab cast. If the browser cannot send audio to the companion as fast as it arrives, something has to pay. Letting delay grow keeps the audio whole and plays it later, up to a limit. Skip ahead (brief gaps) keeps the delay short and the gaps are heard. Choose Skip ahead if a short delay matters more to you than unbroken sound.

Advanced

Section titled “Advanced”

Under Advanced, shown for PCM casts.

Setting Default Choices What it does When to change it
Smoothing 200 ms Off, 100, 200, 300, 500 ms Audio is held briefly at the companion so the late pieces can catch up. Each step adds that much delay. Raise it if every speaker cuts out together. One speaker alone wants a longer speaker head start instead.
Frame size 10 ms 10, 20, 40 ms How much audio the browser puts in each message to the companion. Larger frames use a little less CPU and add that much delay; they make no difference to the speakers’ Wi-Fi. PCM tab casts only. Rarely. Try a larger frame on a computer that is short of CPU.

Under the presets, Settings also shows the Speaker head start (set in the desktop app) and the Added delay these settings come to.

In the extension: Finer points

Section titled “In the extension: Finer points”
Setting Default What it does
Start no louder than On, at 30 A cast starts at the level the room is already at, turned down to this if it is higher. Turn it up once the sound has started. See Volume and start level.
Video sync Off Plays each page’s sound early by as much as the speakers play late. PCM casts only. See Video sync.
Keep the tab awake On Plays the tab’s audio back on this computer, too quietly to hear. Your browser throttles a silent tab, and a throttled tab sends audio late.
Browser-wide capture Off Windows 11 only, with the desktop app on the same computer. Captures the whole browser instead of one tab, which avoids the gaps tab capture can produce. Every tab is then cast as one, always as PCM. See Browser-wide capture.

Each takes effect when you next start a cast.

In the desktop app: Speakers

Section titled “In the desktop app: Speakers”

Open the desktop app’s Settings, then Speakers. These take effect when a speaker next connects.

Setting Default Choices What it does When to change it
Speaker monitoring On On, off Works out every few seconds, from each speaker’s playback position, how much audio it has in reserve. It is what warns you before a speaker runs out, and what clock drift correction steers by. Leave it on. Turn it off and the speaker notices go with it.
Speaker head start 500 ms Off, 250, 500, 750, 1000, 1500, 2000 ms Audio handed to each speaker in advance, so it has something to be getting on with when the Wi-Fi stalls. It adds the same delay, which video sync allows for. PCM casts only. Raise it if one speaker cuts out.
Clock drift correction On On, off No two clocks agree, and over a long cast the disagreement is paid out of the speaker’s reserve. This stretches or squeezes the audio by at most 150 parts per million to keep the reserve level. Needs speaker monitoring. PCM casts only. Leave it on.
Show diagnostics Off On, off Puts each casting speaker’s reserve on its card, in milliseconds. Needs speaker monitoring. To work out which speaker is the trouble.
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