ProAudio — Lip Sync Delay Setup

Modified on Tue, 28 Apr at 11:29 PM

The ProAudio range includes a per-zone lip sync delay of up to 170ms. This is used to compensate for situations where audio arrives at the speakers before the corresponding video is displayed — most commonly when the video path introduces processing delay (such as through a display's image processing, a projector, or a scaler), causing the audio and video to become noticeably out of sync.

When Lip Sync Delay Is Needed

Lip sync delay is typically needed when:

A display with significant image processing delay (common on large TVs in Cinema or Game mode, or on projectors with keystone correction enabled) is used while audio is routed through the ProAudio to a separate speaker system
Audio is output from the ProAudio to speakers in a room where the display signal passes through a scaler or processor that introduces delay
A particular zone sounds ahead of the picture and adjusting the display's own audio delay setting has no effect or is unavailable

If the audio is behind the picture (audio arrives late), the delay is in the audio path rather than the video path and lip sync delay in the ProAudio will not help — adding more delay to audio that is already late will make it worse. In this case, investigate what is introducing delay in the audio chain, or use the display's own audio delay setting to delay the video output.

Setting Lip Sync Delay in the Config Tool

Open the ProAudio Config Tool and connect to the unitLaunch the Config Tool on your Windows PC and connect to the ProAudio. See ProAudio Config Tool Overview if you have not used it before.

Select the zone to adjustIn the Config Tool, navigate to the output zone where the lip sync issue is occurring. Lip sync delay is set independently per zone — adjusting one zone does not affect others.

Open the zone's levels menuExpand the zone settings to reveal the delay control. The lip sync delay parameter is adjustable from 0ms to 170ms in 1ms steps.

Set the delay valueWith a video source playing dialogue or a test clip where mouth movement is clearly visible, increase the delay incrementally until the audio aligns with the video. Increase in steps of 10–20ms until you are close, then fine-tune in 1ms increments.

Save the configurationOnce the correct delay value is set, save the configuration to the unit and to disk. See ProAudio Config Tool — Backup and Restore.

Finding the Right Delay Value

Most displays introduce between 20ms and 100ms of video processing delay. Projectors can introduce more. If you do not know the display's processing delay, start at 40ms and adjust from there.

Display type	Typical processing delay	Starting point
TV in Game mode (low latency)	5–20ms	Start at 10ms
TV in Standard/Cinema mode	40–100ms	Start at 40ms
Large format display (commercial)	30–80ms	Start at 40ms
Projector (no keystone)	20–60ms	Start at 30ms
Projector (with keystone/warp)	60–150ms	Start at 80ms

The delay values above are approximate starting points — actual display latency varies significantly between manufacturers and models. The correct value can only be determined by ear with a suitable test source playing.

Maximum Delay and Stacking

The ProAudio provides up to 170ms of lip sync delay per zone. This covers the vast majority of display processing delays. If you find you need more than 170ms, the display in question has an exceptionally high processing delay — check whether the display has a Game mode or low-latency mode that reduces its processing delay, which would in turn reduce the delay you need to compensate for.

Lip sync delay in the ProAudio applies to the audio output of that zone only. If the video is also passing through other equipment (a scaler, a matrix, a HDBaseT receiver) that introduces its own delay, that is already accounted for on the video side and does not affect the delay figure you need in the ProAudio.

Need help with a specific lip sync issue?
Contact Pulse-Eight support with your display model and a description of the sync offset you are seeing.

UK: 01202 413 610 | US: (858) 748-8250 | support@pulse-eight.com

ProAudio — Lip Sync Delay Setup

When Lip Sync Delay Is Needed

Setting Lip Sync Delay in the Config Tool

Finding the Right Delay Value

Maximum Delay and Stacking

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