Specifications

2.29

Applications Manual

Revision 1.11Prism Sound dScope Series III

4 Dolby Digital 2-channel

The dScope can perform conformance testing of Dolby Digital 2-channel replay devices such as DVD

players (in conjunction with the

Dolby DVD Test DVD

), or set-top-boxes (in conjunction with the

equivalent .ac3 test files).

An easy-to-use script and accompanying Configurations are provided which provides a menu of all

available tests, and guides you through each test. This script and the accompanying Configurations

are installed automatically from the dScope's installation CD; updates may be obtained from

www.prismsound.com

, or by contacting Prism Sound or your local distributor. Contact details are

provided in the

General information

section.

Details of how to get started with Dolby Digital 2-channel testing are in the

Overview

section.

4.1 Overview

This document describes how to perform the two-channel tests required by Dolby Laboratories for

DVD players and broadcast consumer products, as specified in the

Dolby Test Procedure document

using a Prism Sound 'dScope Series III' audio analyzer. For details of the individual tests, refer to the

Dolby Digital 2-channel tests reference

section of this manual.

Running the tests

The dScope's Dolby Digital 2-channel tests are accessed from the Default User Bar of the dScope,

under "Applications:Dolby Digital 2-channel" if that User Bar is configured, or alternatively by running

the "Dolby Digital 2Ch.dss" launcher script by selecting "Run Script" from the Automation menu. The

launcher script presents a tests menu, from which each test may be automatically performed, with

prompting for the required tracks from the

Dolby Digital Test DVD

Additional help during testing

When starting the launcher script, the operator is prompted to select whether additional help is

required in either (or both) of the following areas:

Test methods;

Test specifications (pass/fail limits);

If either of these is selected, then additional message boxes are generated during running of each

test which describe the selected parameter(s) for that test.

Note about Reference Level

The first test listed in the tests menu is the 'Reference Level' test. This test establishes an ideal 'full-

scale' amplitude reading for the Dolby Digital device under test. This level is used as a reference in

most of the other tests, and so it is important that the Reference Level test is performed first. Failure

to do so will result in an error message when other tests are attempted.