Dolby TrueHD Surround Sound - dummies

By Danny Briere, Pat Hurley

The Dolby TrueHD surround sound format supports up to 13.1 channels of surround-sound goodness, like Dolby Digital Plus. However, Dolby TrueHD is a lossless format. That means that the sound being encoded into the Dolby TrueHD data stream will come out the far end (at the decoder in your home theater) exactly the same as it went in.

For the first time ever, the home consumer can experience multichannel movie soundtracks exactly as they were heard in the mixing studio during content production. Most other surround-sound formats are lossy. (DTS-HD Master Audio is also a lossless format.) With Dolby TrueHD, the audio track is bit-for-bit identical to the studio master.

Dolby TrueHD uses the same MLP (Meridian Lossless Packing) encoding as DVD-Audio, but with an even higher bit rate, which allows for more channels of high-resolution audio.

A lossy encoding system throws away bits of the audio (using sophisticated acoustic modeling that determines what your ears actually do and don’t hear) to achieve greater compression of the audio. Greater compression is a good thing if you have a limited amount of storage space on a disc or a limited amount of bandwidth (or data throughput) on your video transmission system (like cable or satellite). But if you have the space (or the bandwidth) — like Blu-ray does — you can compress your audio less and get better sound quality.

Dolby TrueHD support is included in Blu-ray disc players and many Blu-ray discs. So you’ll be able to enjoy some awesome lossless surround sound when you watch a movie in this new format.

Like Dolby Digital Plus, to listen to Dolby TrueHD, you need a receiver capable of decoding Dolby Digital Plus with an HDMI 1.3 connection. If you don’t have Dolby TrueHD decoding and HDMI 1.3 in your receiver, you use the Dolby TrueHD decoder in your DVD player and connect it to your receiver using either an HDMI 1.1 connection or a set of analog audio cables.