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High-definition surround sound explained

Blu-ray and HD DVD don’t just offer awesome pictures – thay can also offer substantially better sound quality too. We’ve written a great deal about compression formats, usually when discussing the pros and cons of MP3. But it’s equally an issue in home cinema: in order to maximise disc space (especially with the rather more memory-starved traditional DVD), some form of compression of the soundtrack is usually necessary.

But things are changing. It’s now possible to store an uncompressed PCM soundtrack on a Blu-ray or HD DVD disc, while the new compressed formats include two ‘lossless’ formats – Dolby True HD and DTS Master Audio. This means exactly what it says: a lossless signal, when decoded, should replicate exactly the original uncompressed signal.

As you can see in the diagram above, the bitrates of these lossless formats are much bigger than traditional data rates: at a maximum bitrate of 24.5 mbps, DTS Master Audio delivers roughly 50 times as much information, per second, to your receiver as a standard Dolby Digital soundtrack on DVD.

Data rates tell their own story: the more information you have, the better it can sound. We’ve listed the tech specs of all the current high-definition players in the panel below. So with Blu-ray and HD DVD, you’re in for a sonic treat as well as great pictures.

Technorati Tags: Blu-ray, Dolby Digital, Dolby True HD, DTS, DTS HD, DTS Master Audio, HD DVD, home cinema

Andy Clough

Andy is Global Brand Director of What Hi-Fi? and has been a technology journalist for 30 years. During that time he has covered everything from VHS and Betamax, MiniDisc and DCC to CDi, Laserdisc and 3D TV, and any number of other formats that have come and gone. He loves nothing better than a good old format war. Andy edited several hi-fi and home cinema magazines before relaunching whathifi.com in 2008 and helping turn it into the global success it is today. When not listening to music or watching TV, he spends far too much of his time reading about cars he can't afford to buy.