Dolby Laboratories Multichannel Audio Tool DP570 - Manual (Page 113)

Parameter Definitions
Dolby ® DP570 Multichannel Audio Tool User’s Manual 97
Audio Production Information
This parameter indicates whether the mixing level and room type values are valid. Yes
indicates that a receiver or amplifier can use these values. No indicates that these values are
invalid. In practice, only high‐end consumer equipment implements these features.
Mixing Level
The Mixing Level parameter describes the peak SPL during the final mixing session at the
studio or on the dubbing stage. The parameter allows a consumer’s amplifier to set its
volume control to match that of the mixing room. This control operates in addition to the
dialogue level control, and is best thought of as the final volume setting on the consumer’s
equipment. This value can be determined by measuring the SPL of pink noise at studio
reference level and then adding the amount of digital headroom above that level. For
example, if 85 dB equates to a reference level of –20 dBFS; the mixing level is 85 + 20, or
105 dB.
Room Type
The Room Type parameter describes the equalization used during the final mixing session
at the studio or on the dubbing stage. A large room is a dubbing stage with the industry
standard X‐curve equalization; a small room has flat equalization. This parameter allows
an amplifier to be set to the same equalization as that heard in the final mixing
environment.
Copyright Bit
This parameter indicates whether the encoded Dolby Digital bitstream is copyright
protected. It has no effect on Dolby Digital decoders and its purpose is purely to provide
information.
Table D-11 Audio Production Information Settings and Definitions
Audio Production
Information Setting Definition
Yes Mixing Level and Room Type parameters are valid.
No Mixing Level and Room Type parameters are invalid
and should be ignored.
Table D-12 Mixing Level Settings
Mixing Level
80 to 111 dB in 1 dB increments
Table D-13 Room Type Settings
Room Type
Not Indicated
Large
Small
Table D-14 Copyright Bit Settings
Copyright Bit
Yes
No