Appendix 1

3 Initial Audio Workfl ow,
Importing Production
Audio, and Syncing
The Production Audio Recorder
There are several decisions made in production that determine workfl ow in postproduction. The use
of time code recorders and slates, analog or digital recorders, optical disc recorders, and fl ash
memory recorders dramatically alter the postproduction workfl ow. You may have little or no input
on the choice of the recorder, but if you understand their operation, you will be better able to plan
your workfl ow.
Audio recorders, used in motion picture production, must be able to play back at the exact speed
they recorded. Nagra (and some other) analog recorders achieve this by recording a pilot signal in
the audio and then comparing it to a known reference in playback. Several Nagra models, such as
the one shown in Figure 3.1, can record time code, but most do not. For years, this was the standard
for motion picture production and is still widely used by analog purists and low-budget, independent
productions. It’s an excellent system and outperforms many digital alternatives. Analog
recorders usually record to one-quarter-inch reel-to-reel tape; however, some record to audio cassette
tape.
Digital recorders are much more widely used. They achieve sync by sampling the sound at a very
accurate rate and playing those samples back at the exact same rate. While 48 KHz and 96 KHz are
most often used, several sample rates are used and new ones come along now and then. But the key
to sync is accuracy: playing at the exact same sample rate as the recording.
In production, sync is achieved by locking each device to its own internal clock. In postproduction,
all playback machines and recorders need to be locked to the same clock. While sync can be held
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