Audio
Turning audio on host-side, the four states of the speaker button, the free ten-second sample, Low Latency versus Lip Sync, and mute behavior.
Audio is a separate Mercury Transmit stream from the video. It has to be enabled on the host, and the phone plays it through whatever output the device is currently using.
Enable it on the host
In Premiere Pro: Preferences → Playback → Video Device, and tick PreviewMonitor's Audio Stream. Leave Video Stream ticked too. Audio Stream is a column in that device table beside Video Stream — there is no separate "Audio Device" section to find. (Adobe renamed this menu to Settings in the 2025 releases; same item.)
This page is Premiere Pro only. After Effects has no audio path whatsoever — no push, no clock source, nothing to enable in Preferences → Video Preview. Everything below, including the speaker button's four states and the free sample, applies only to a Premiere Pro host.
The phone cannot tell the difference. The app assumes a host has audio until the plugin reports otherwise, and the After Effects side never reports otherwise — so the speaker button never reaches its orange warning state there. It looks like a working mute toggle and delivers permanent silence. See No audio.
The plugin works out whether audio is switched on by watching whether audio samples actually flow during playback, and it holds that verdict across pauses — so the phone stays correct while the timeline is parked.
If the phone reports audio is off, tapping the speaker button opens a Turn on audio walkthrough with the same three steps and a zoomable reference shot of the Playback preferences panel.
Tap the reference image to zoom it — the checkbox under Video Device is small.
The four states of the speaker button
The button is the second control in the HUD row and means four different things:
| State | Appearance | Tap does |
|---|---|---|
| Audio off in Premiere Pro | Orange speaker-slash, orange ring, small orange exclamation badge | Opens the Turn on audio guide |
| Free tier, idle | Speaker-slash with a blue lock badge | Starts a 10-second sample immediately |
| Free tier, sampling | Speaker with waves, plus a countdown pill (7s) | Ends the sample early and returns to muted |
| Pro | Speaker with waves when audible; speaker-slash with an accent ring when muted | Toggles mute |
The lock is a badge, not a different glyph — a substituted icon reads as a malfunction rather than a locked feature.
The badges are drawn on top of the HUD's glass layer rather than on the button itself, which is why they sit clearly in front.
The free ten-second sample
Continuous audio is Pro. The free tier gets on-demand ten-second samples instead, with no limit on how many you can take.
Tapping the speaker on the free tier starts a sample straight away — there is no explanatory sheet in the way. The demo is the pitch; the upgrade offer comes afterward.
The contract, exactly:
- The countdown starts on the first audible frame, not on your tap. "Audible" means a peak magnitude of at least 0.001, about −60 dBFS. A paused timeline, an empty region, or a faded-out tail would otherwise burn the sample on silence.
- Once it starts, it runs on a plain wall clock for 10 seconds — even if playback stops. You were promised ten seconds, not ten seconds of playback.
- If nothing audible arrives within 60 seconds of the tap, the sample is abandoned silently. Nothing plays, no countdown ever appeared, and no upgrade prompt is shown — nobody heard anything, and you may not even be holding the phone.
- The last 0.3 seconds fade out linearly, so the end reads as deliberate rather than as a dropout. The fade is applied per audio sample, so it survives a format change mid-taste.
- A completed sample ends muted and then offers the upgrade, while the ten seconds you just heard are still the most recent thing that happened.
- Tapping the speaker mid-sample ends it early and returns to the ordinary muted state. The button never goes inert for ten seconds.
The pill counts down in whole seconds and disappears when the sample ends.
Buying Pro during a sample ends it cleanly — no countdown, no fade — and audio simply continues.
Sync modes
Settings → Audio → Sync picks between two jitter-buffer profiles. Both are entirely client-side: the plugin streams identical PCM either way, so switching costs nothing on the host.
| Mode | Buffer cap | Prime |
|---|---|---|
| Low Latency (default) | 150 ms | 40 ms |
| Lip Sync | 500 ms | 200 ms |
The buffer cap bounds how much audio can queue before the oldest is dropped, which is what keeps latency near the target. The prime is the cushion the playback callback builds before it starts draining, and rebuilds after an underrun — it deliberately delays audio so it lands nearer the video's own decode and display delay.
Use Low Latency when you are cutting to a beat and want the sound tight. Use Lip Sync when you are checking dialogue against picture and want audio and video to line up, at the cost of a steadier but later feed.
Changing the mode rebuilds the cushion at the new depth, so expect a brief resettle.
Mute
Mute sets the mixer's output gain to zero. The stream keeps draining underneath, so un-muting resumes at the live point rather than replaying a backlog — the toggle is instant in both directions.
Mute is not persisted. Every session starts un-muted on Pro, so a mute you forgot about last week cannot silently kill your audio today. The free tier starts silent, because that is the only state it can honestly be in.
Interruptions and route changes
Audio survives the things that normally kill a long session:
- Interruptions — a phone call, Siri, or an alarm. The engine pauses when the interruption begins and re-activates the audio session and restarts when it ends.
- Route changes — AirPods or headphones connecting or disconnecting. Either direction re-activates the session and restarts the engine.
Without this handling, one phone call would leave a multi-hour monitoring session silent for the rest of the day.
Nothing is required from you: recovery is automatic. If audio does stay silent, see No audio.
Preview from Photos or Files
A locally-imported clip plays its own audio through the device — it does not go through any of the above. That screen has no speaker button, because there is no host stream to mute. See Preview from Photos or Files.
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Layouts and safe zones
All twelve layout modes, the Universal Safe Zone with its opacity and color controls, the caption editor, and when the picture fills versus letterboxes.
Encoding settings
The settings panel — encoder engine, codec, GOP mode — plus the Resolution Limit chip on the HUD, and exactly what Reset to Defaults restores.