Playback audio tempo synced precisely to camera framerate — any mismatch causes visible lip-sync drift. Essential control for music videos and live-performance scenes.
Working with playback on set means: you play the music or dialogue through speakers while the actors or musicians perform in sync. The playback speed is not arbitrary – it must be precisely matched to the camera's frame rate. If the music runs even minimally faster or slower than the camera is recording, lip-sync errors will occur that cannot be fixed in post-production. At 24fps (cinema) or 25fps (PAL), picture and sound will noticeably drift apart within seconds, even with tiny deviations.
In practice, this means: before playback starts, the audio file must be normalized to the exact project frame rate. A piece of music originally recorded at 48kHz/tempo 120 BPM requires a different playback speed than the same piece at 44.1kHz. Many productions use dedicated playback players for this, such as Sennheiser IEM systems or digital playback controllers, which guarantee this synchronization. You set the frame rate in the system – the player then automatically adjusts the speed. No manual fiddling with audio controls.
It becomes particularly critical in music videos and live performance recordings. Here, the viewer sees the singers' mouths directly – any temporal shift is immediately noticeable. Therefore, multiple monitors run during the take: one for the performers (so they can hear they are in sync), one for the director/AD, and usually a visual sync check in the video village. Some crews work with timecode generators to keep picture and sound technically coupled.
A common practical error occurs during project conversions: a scene was shot in 23.976fps, but the editing suite is internally running at 25fps. The playback file then needs to be pitched accordingly – not simply stretched, but with tempo preservation. Otherwise, your singer will suddenly sound like a chipmunk or a baritone. Modern DAWs and players handle this, but it requires attention in the workflow. Best practice: always have the playback file prepared by the sound department and cross-check with the DIT before going to set.