What's the difference between standard DD5.1 and 640 Kbps Dolby 5.1? (1 Viewer)

[John Pine]

Is it just a higher resolution? Is it approaching SACD sound quality? I've read that the new Pink Floyd Pulse concert DVD has both tracks. Will my old Denon DVD-2900 play the 640 Kbps version?

 

[Philip Hamm]

Dolby Digital 5.1 can be executed at many Kbps resolutions. 640 is much higher than standard, and should result in a lower compression ratio, therefore better sound. Much like larger higher kbps MP3 files sound better than smaller lower kbps ones. It should be compatible with any DVD player, I don't understand why they would have to include another "compatability" mode. DVD-Video is capable of much higher throughput audio than this in PCM mode.

 

[ChristopherDAC]

640 kbps is the maximum bitrate allowed in the Dolby Digital specification. On the other hand, the DVD specification doesn't allow for more than 448 kbps. I can only imagine that they're packaging it as if it were a half-bitrate dts track, or something, which makes no sense, but would require a "compatibility" audio track. Anyway, I wouldn't call it an audiophile-quality option, but it should be roughly equivalent to full-bitrate dts for perceptual quality.

 

[John Pine]

Understood, good info guys!

Wonder why they just didn't go with a DTS version? Maybe they "cheaped out" and did the "640 Kbps version" instead.

 

[Philip Hamm]

DTS would require higher bandwidth to achieve the same sound quality, bandwidth that they would rather have to maximize the picture I would assume.

 

[JeremyErwin]

Technically, I suppose it is. But it's a long way off.