DVD Sound Connections
DVD Video offers superb performance and playback of digital surround sound, and a range of options for connecting the DVD player to a variety of home cinema systems. This page will guide you through the audio connection options available for most DVD players, home cinema amplifiers, and add-on surround sound decoders.
DVD INTRODUCTION  
DVD FORMAT
DVD PLAYERS
DVD BUYING
DVD SOUND CONNECTIONS
DVD VIDEO CONNECTIONS

 

INTRODUCTION

With the high storage capacity of DVD discs, much more information can be encoded when compared to Compact Disc and Laserdisc. This has been used to great effect by encoding DVD-Video discs with special features and a choice of soundtracks. One of the biggest advantages has been the inclusion of a Dolby Digital 5.1 Surround Sound track, in addition to the normal stereo or Dolby Surround track.

To take advantage of the superior Dolby Digital format, you need a Dolby Digital Decoder within your system, either included within the DVD Player itself, or in a separate Home Cinema Amplifier, Receiver or Processor. Each of the 5.1 audio channels found in a Dolby Digital track are stored as a digital data stream which is decoded (and separated) by the Decoder into six analogue audio signals that can be used by an Amplifier to drive the Speakers.

There are a number of ways to decode and amplify the Dolby Digital soundtrack depending on what equipment you are using. Below is a guide to the most commonly used hardware configurations in DVD/Dolby Digital 5.1 systems.

 
   

THE CONNECTIONS

The diagrams below may seem a little complicated at first glance, but it's not really all that difficult to understand. There are basically two types of connection in use here. The first is a single "digital cable" and the second is a "Six-Channel" analogue phono connection.

Essentially, the digital cables are used to carry the raw, undecoded digital audio data stream from the source component to the decoder. When the source component has its own built-in decoder, a digital cable is not needed. Once the data stream has been decoded, you are left with six channels of analogue audio that needs to be passed from the decoder to an Amplifier. This is done using the Six-Channel phono connection - basically, six separate phono interconnects (or three pairs), one for each decoded channel. The Six-Channel connection is only needed if the decoder is built into the source component (DVD Player) or if a separate digital decoder is attached to a home cinema amplifier. If the decoder is built-in to the amplifier, a six channel connection is not needed - digital cable is used. All this makes more sense if you look at the diagrams below:

 
   
 

DVD PLAYERS WITHOUT A
DOLBY DIGITAL DECODER

If your DVD Player has no Dolby Digital decoder built-in, you'll need to connect it to a suitable unit using a digital cable. Decoders are found as separate components, or included inside some Home Cinema Amplifiers and Receivers.

 

   
 

SYSTEM 1

System 1

  In this system, a separate Dolby Digital Decoder receives the sound data from the DVD Player through a digital cable. The DVD player itself has no Dolby Digital decoder, but can read and output a Dolby Digital data stream. Once the Decoder has separated the six audio tracks and converted then into analogue signals, they are sent to an A/V Amplifier using six phono cables - one for each decoded channel. In this case, the A/V Amplifier needs to have a 6-channel input on the back, but doesn't need a decoder.
   
 

SYSTEM 2

System 2

 

This system is suitable for listening to Dolby Digital where a Dolby Pro-Logic Processor has been added to an existing stereo Hi-Fi Amplifier. It uses a separate Dolby Digital Decoder to separate the six audio tracks and convert them to analogue signals. The separated tracks are distributed be the Processor before amplification - the two Main Front channels are amplified by the Hi-Fi Amp, while the two Rear Surround and the Centre channels are amplified by the Processor itself. A Sub-Woofer may be added, provided the Processor has the necessary phono output. Most Processors with a 6-channel Input have a Sub-Woofer output as they are designed for use with Digital 5.1 Surround.

   
 

SYSTEM 3

System 3

 

The simplest and easiest ways to listen to Dolby Digital is to base your system around a Home Cinema Amplifier or Receiver with its own Digital Decoder built-in. This is what I have done in my system and only uses a single digital cable to send the data stream to the Receiver. The amplifier/receiver also, obviously, amplifies the decoded channels, so a 6-channel connection is not needed.

   
 

DVD PLAYERS WITH A
BUILT-IN DOLBY DIGITAL DECODER

Getting a DVD Player with a built-in Digital Surround Sound Decoder is a simple way to add DVD to an existing Home Cinema Amplifier, or Processor, that has a six channel input. The quality of the actual decoders found in this type of player are generally good and perform well. It will usually be a little less expensive to follow this route to a Dolby Digital system, if you have existing A/V hardware with the required 6-channel Input.

   
 

SYSTEM 4

System 4

 

Because the Dolby Digital data is separated and turned into analogue signals inside the DVD Player, a digital cable is not needed. Instead, six phono cables carry the separate signals to an Amplifier with a 6-channel Input. A Dolby Digital decoder is not required in the Amplifier.

   
 

SYSTEM 5

System 5

 

This system shows the easiest way to add Dolby Digital from a DVD Video source to a Home Cinema using a Dolby Pro-Logic Processor and stereo Hi-Fi Amplifier. The decoding is done in the DVD Player and the separated analogue signals are passed to the Processor through six phono cables. The Processor must have a 6-channel Input in order to accept the phono signals.

   
 

ADDING ANOTHER DECODER
TO A DOLBY DIGITAL AMPLIFIER

If you have a Home Cinema Amplifier with a built-in Digital Surround Decoder, chances are that it will be for decoding Dolby Digital. This is fine as both DVD Players and DVD discs are based around the Dolby Digital technology. But what about the future formats, or adding existing sound formats such as DTS to a Dolby Digital system? There's no need to trash your existing Amplifier - simply add a separate Digital Decoder that can handle the sound format you want. To do this you need an Amplifier with a 6-channel Input. This is a feature that is well worth having and allows flexibility for future upgrading, even on Amplifiers or Processors that already contain a Digital Surround Decoder.

   
 

SYSTEM 6

System 6

 

This diagram shows how a second Digital Surround Decoder can be added to an existing Dolby Digital equipped system. In this example, a DTS Digital Surround Decoder is added and receives a data stream from a DVD Player that can read and output a DTS signal. The separated DTS channels are passed onto the Amplifier using six phono cables.

Most DVD Video Players have both types of digital output (Optical and Coaxial) so connecting two digital cables shouldn't be a problem. What may be a problem is where you already use the 6-channel Input on your Amplifier to receive signals from an existing Dolby Digital Decoder, either within a DVD Player or in a separate unit. To add another Decoder to this type of system means that you either need two sets of 6-channel Inputs on the Amp, or change the Amp to a model with both Dolby Digital and DTS Decoders included. Some Dolby Pro-Logic Processors, including the very popular Yamaha DSP-E492, have two sets of 6-channel Inputs for connecting two separate Digital Decoders.

   
 

In general, you should try and start off with hardware that contains Decoders for both DTS and Dolby Digital, such as the Sony STR-DB930 Receiver. With a DVD Player that can read and output DTS and Dolby Digital, only a single digital cable is needed, and a 6-channel input (as found on the Sony) is not likely to be needed. However, most manufacturers still include a 6-channel input on hardware with DTS and Dolby Digital. This is not intended for adding further home cinema decoders, but for adding DVD-Audio players that will contain their own type of high quality audio decoding for up to 6 channels of sound.