Specifications

Standards and Practices for Authoring Dolby

Digital and Dolby E Bitstreams

How can I set the DP562 decoder to emulate the most common dynamic

range control settings on consumer decoders?

The front panel of the DP562 has four buttons that deal with the dynamic range

control settings: None, Custom, Line, and RF. None is a professional set-up mode

that defeats both dynamic range control and dialnorm, and is only used for installation

and signal tests. Once a specific dynamic range profile has been selected, simply

pressing RF emulates the selection of “late night mode” in a consumer decoder, while

Line mode emulates a more moderate dynamic range control effect that a consumer

may select. Line mode within the DP562 decoder also allows limited scalability when

not downmixing.

Custom is commonly used to turn dynamic range control off while still asserting the

dialnorm parameter, which emulates the consumer choosing to listen in a full

dynamic range mode. Some high-end consumer decoders offer a scalable boost and

cut, and Custom mode can be tailored to reflect this as well.

Note: These modes are also included in the DP570 Multichannel Audio Tool.

I’m using a consumer decoder to monitor my Dolby Digital stream. How

do I set it up so that I can use it for mastering my Dolby Digital stream?

While it is preferable to use a reference decoder such as the DP562 for mastering

purposes, it is possible, albeit unwieldy, to use a consumer decoder.

Consumer decoders do not offer easy access to the many downmix and dynamic

range options that may be available to the consumer at home. In addition, not all

consumer decoders offer every feature that is available in Dolby Digital technology.

A reference decoder like the DP562 has all the necessary controls for mastering on

the front panel to facilitate changing downmixing conditions and dynamic range

profiles quickly.

If budget constraints require the use of a consumer decoder, it is suggested that the

engineer refer to the operation manual of the device for specific information.

Why is it called a Low-Frequency Effects (LFE) channel? Isn’t it just the

subwoofer?

Actually, LFE and subwoofer are two very different things.

Typically, the term “subwoofer” refers to a speaker that reproduces very low-frequency

information that the main channel speakers (however many there are) are incapable of

reproducing. Low-frequency sounds that are normally found on the main audio

channels are directed to the subwoofer speaker for added punch in the low range. In this

fashion, a subwoofer acts as a complement to extend the range of the main speakers,

which may find it difficult, if not impossible, to reproduce these low frequencies.