The Basics - B&K p/n 12698 Owner's Manual

The following is intended to familiarize users with common terms and applications of Home Theater equipment.
Sources -
your A/V System Controller can directly provide audio from its built-in AM/FM tuner. It can also provide
limited video from its on-screen menu system. Typically you will want to connect a number of additional sources
(VCR, DVD player, etc.) to your A/V System Controller. Your A/V System Controller is designed to accomodate a
wide range of audio and video signals.
The following table lists the most popular home theater media and how the audio information is stored.
Source Media
Audio Cassette
Video Cassette
Laserdisc (LD)
Compact Disc (CD)
Digital Versatile Disc (DVD)
Satellite Broadcast
Digital Audio Tape (DAT)
Digital Compact Cassette (DCC)
Minidisc (MD)
Analog vs. Digital Audio -
how they are delivered to your A/V System Controller from the source. Analog signals exactly represent the sound
you will hear through a continuously varying voltage. Audio and video cassettes are analog recordings and are
normally delivered to your A/V System Controller over a pair of coaxial audio cables.
Digital signals closely approximate the original audio signals with a set of numbers referred to as a bitstream. CDs
and DVDs are sources of digital audio and are normally connected to your A/V System Controller through a
coaxial or optical digital cable. There are several different bitstream formats available. The simplest format is
called Pulse Code Modulation (PCM). In PCM, the bitstream directly represents the original 2-channel audio. In
Dolby Digital and DTS (see "Surround Formats" below) bitstreams are modified using a process called
compression to squeeze more information into limited space. DTS squeezes 5.1 channels into the space normally
required for two uncompressed channels, while Dolby Digital squeezes 5.1 channels into about ¼ the space
required for two channels. Your A/V System Controller automatically detects the bitstream currently being provided
from the source and performs the required decompression and surround processing. If no digital signal is present
your A/V System Controller will automatically switch to analog processing.
All sounds that you hear from your speakers are analog. Digital signals are automatically converted to analog by
your A/V System Controller before being output to your speakers.
If analog signals exactly represent the audio, while digital signals only approximate it, why would I want to
use digital?
All analog sources add some amount of noise and distortion to the audio signal. Additional noise can be
picked up through the cables from the source to your A/V System Controller. It is impossible for the A/V
System Controller to tell the difference between the desired signal and the added noise and distortion, so
it reproduces both of them. The result is increased background noise and decreased dynamic range and
fidelity. Digital signals are virtually immune to noise and distortion. The A/V System Controller can,
therefore, reproduce the signal with the greatest possible fidelity. We recommend you use digital signals
wherever possible. Also Dolby Digital and DTS (see "Surround Formats" below) work only with digital
signals.
Surround Formats - Your source material will be in one of five possible formats described below.
Monaural (Mono)
Modern recordings are seldom made in this format, but most older movies and music are available only in
this format. You may get mono from any source - digital or analog. Sound will normally come only from
your center channel speaker, but your A/V System Controller can produce mono in two or four channels

THE BASICS

Analog
X
X
X
X
This refers to the method used to place audio information on the source material and
- This is the oldest format available. It contains a single, full range audio channel.
PCM Dolby Digital
X
X
X
X
X
X (compressed)
X (compressed)
5
DTS
X X
X X
X X
X
X X
p/n 12698 Rev. 9808B