by Marshal Rosenthal

Lost in this resolution shuffle is an underrated aspect of HD: audio. HD DVD and Blu-ray discs feature the new “flavors” of Dolby Digital Plus, Dolby TrueHD and DTS-HD. Craig Eggers, Dolby’s senior manager for consumer electronics marketing, says Dolby Digital Plus delivers up to 7.1 discrete channels of audio at a higher quality, and even “plain vanilla” Dolby Digital now runs at a data rate higher than that found on DVDs.

Eggers says the best audio performance comes from an HDMI connection, but this requires an A/V receiver that can handle HDMI. If that’s not an option, analog connections can be used. In this case the high-resolution pulse-code modulation (PCM) signal in the high-def DVD player undergoes digital-to-audio conversion inside the player and is exported to your connected A/V receiver. This process lets you take advantage of the newer high resolution audio streams.

The final choice is to use a traditional digital (optical or coaxial) output, but this method limits you to Dolby Digital or DTS audio. When using optical or coax, the high resolution PCM signal in the player is re-encoded as a 640kbps Dolby Digital signal for playback compatibility through any legacy digital home theater receiver or processor. “Listeners will still enjoy an increase in audio performance compared to standard-definition DVD playback,” says Eggers.