Video Asylum

Posted by Brad G. on May 14, 2001 at 01:09:57

I just downloaded the Dolby 2 pdf. file from Dolby.

http://www.dolby.com/tech/l.wh.0007.PLIIops.pdf

It displays some of the advantages but most seem to be aimed at music.

For Video, it offers faster logic steering, no 7Khz surround channel limits, and stereo surround channels. Oh yeh, better bass management. This is most likely no big deal as most good receivers have implented their own good bass management.

Since all prologic encoded material only includes "4" channels(front left and right, center, and the surround channel), how are they converting the 'original' mono surround channel to stereo? How can they create something that was never there to begin with?

I originally had high hopes for this. After reading this information sheet, my optimism for DPL 2 has shrunk. It's main strengths seem to be for music, which would still be degraded by the matrix processing. If you like DSPs that alter music from it's original form, than Yamaha's DSPs and many other maker's DSPs should do just fine.

If DPL 2 derived stereo surround outputs from an original encoded source, that would be great. Unfortunately, all DPL encoded material is only in a "mono", single surround channel so "making up" stereo surround channels is altering the original signal from accuracy. It sounds as it could do more harm than good, which is true of most DSPs. Hope I'm wrong.