Choosing a high definition sound system

Great sound can make any home entertainment experience much more enjoyable… including sport.

This is especially going to be the case in this year’s Beijing Olympic Games. The packed stadiums, the tens of thousands of cheering fans – and let us not forget the sheer spectacular entertainment of the Opening and Closing Ceremonies!

You are simply not going to get as much out of the Olympics this year if you rely solely on your TV’s built-in speakers.

Surround sound

Over the past five decades, the two most important changes in the cinema world have both invloved sound. One of these is the introduction of high fidelity sound. If you’ve ever watched a 1940’s movie, you will have noticed how harsh the voices sound, how pinched the music. Since then, moviemakers have been increasingly seeking realistic sound, and have now largely succeeded.

The other change has been the introduction of surround sound. Moviemakers fiddled with forms of this as far back as the 1950s, but it was inconsistent and relied upon expensive new equipment fitted to very few cinemas.
It wasn’t until the late 1970s that the first viable – and widely accepted – surround sound system came into movies. It was called ‘Dolby Stereo’, but these days we know it in the home context as Dolby Pro-Logic.

This system managed to pack four separate ‘channels’ of sound into two. The two-channel sound (what we call stereo) could be recorded on the edge of the film. With a Dolby Stereo decoder, centre and rear sound could be extracted. The first big movie with Dolby Stereo established its worth in its opening moments: 1977’s Star Wars had the spaceship coming down on the screen from over the audience’s heads, and the sound did the same. It was something that had never been experienced before by audiences, and it was utterly thrilling.

Since then surround sound has been improved. In 1992, Dolby Digital 5.1 introduced five full channels – two of them surround – and a dedicated bass channel for ‘Low Frequency Effects’. Soon DTS followed. Both have since been enhanced with 6.1 and 7.1 channels.

The Olympics

The 2008 Beijing Olympic Games will not be benefiting from 5.1 surround sound. Instead it will be delivered in regular stereo.

However, we still think that TV speakers will not be enough. For one thing, full high fidelity sound is rarely delivered by TVs. For another, our experience tells us that surround sound will actually be buried within that stereo sound.
When we are watching the football with our big screen, we also switch on our sound system. Then we select Dolby Pro-Logic for listening mode, and what do we find? We find that the sound of the crowd surrounds us, envelopes us. The stereo sound is actually not very much different to the ‘Dolby Stereo’ sound used in movies from the late 1970s.
Since then, though Pro Logic processing has become a lot better. Dolby Pro-Logic II can create a fill 5.1 channel sound, and if you have a 6.1 or 7.1 channel system, Dolby Pro-Logic IIx can make use of the extra rear speakers. Similar systems are available from DTS (called Neo:6) and Circle Surround.

Alternatively, some systems can use ‘Digital Signal Processors’ (DSP) to artificially enhance the surround experience even further. Most home theatre receivers have some form of this.


Most TVs have some form of pseudo surround sound, which they create by fiddling with the sound signal – some are even called ‘Dolby Virtual’. However these are of limited effectiveness. For real surround sound you need a home theatre audio system and multiple loudspeakers.

This can be in the form of a ‘home theatre in a box’ system, single speaker surround – or ‘front surround’ – solutions, or in separately purchased components, such as a home theatre receiver and surround speakers. While the latter generally delivers better performance, all three offer a huge improvement over the surround of a TV.

The following associated articles will help guide you through the things to look for in these different kinds of systems:

AV receivers – the control centre of your high definition sound system

Speakers for high definition home theatre

All-in-one sound solutions for high definition home theatre