Specifications

5.1-Channel Production Guidelines Preparing the Source Delivery Master
6-3
When the Surround channel is mono, allocate it to both tracks 5 and 6 with 3 dB
attenuation applied to each signal. Use the following formula:
Track 5 = Track 6 = 0.707 * S
Follow this recommendation even when track 4 also contains the S signal, which
should always be at normal level on this track. Indicate on the tape label clearly that
tracks 5 and 6 each contain the S signal at -3 dB relative to their normal levels.
6.3 Reference Levels
The standard reference level is -20 dBFS for digital recorders (0 VU for analog
recorders). This level is typically +4 dBu from professional consoles and -10 dBV
from semi-professional consoles. When transferring from 35 mm magnetic film
(analog), attenuation and/or peak limiting may be needed to avoid digital clipping. If
used, these processes will affect what value is selected for the Dolby Digital Dialog
Normalization parameter setting during encoding and will require complementary
gain recovery in the reproduction chain.
A 30-second, 1-kHz alignment signal at -20 dBFS should appear on all channels at
the beginning of the source delivery master prior to program start. The finished
master should contain at least 30 seconds of digital black after the alignment signal
and before each subsequent program. Each title should begin with at least two
seconds of encoded digital black.