According to www.twice.com Dolby will unveil their 6.1 and 7.1 channel DPL IIx technology at CEDIA. Dolby expects




[This message has been edited by Will (edited September 02, 2003).]

More an extension of current PL II technology than something totally new, IIx will upsample up to 7 independent channels from stereo sources and generate up to 2 additional surround channels (yeah, stereo rears) from discrete 5.1 material. Hopefully, like any Dolby licensed technology, it will eventually become ubiquitous, appearing in even the lowest priced 7.1 gear (as PL II does now).

Pro Logic IIx press release:

http://www.dolby.com/events/CEDIA/PLIIx/

Pro Logic IIx FAQ (very thorough):

http://www.dolby.com/events/CEDIA/PLIIx/faq.html

Best,
Sanjay

sounds intriguing!

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Play it LoUd!!

Will be interesting if the 950 would get this upgrade, as DPL II with the CES mode is potentially very similar.

IIRC DPL II with the CES mode upconverts to 6.1 distinct channels with the 2 back channels being in mono, whereas I think DPL IIx upconverts to either 6.1 or 7.1 distinct channels. Incidentlaly, the twice.com link says

Kevin, How do you figure? PLIIx and CES work quite differently.

PLIIx will take the logic steering that PLII already does and expands it into the 2 surround-back channels. This means if a certain sound is meant to image in the left rear channel, that sound will also be actively supressed in the left side channel for better directionality. You already hear this sort of cancellation with PLII on the front 3 channels, where the centre channel content is supressed in the front left & right channels, keeping them free of dialogue.

Compare that to the simple electrical summing that CES does. Common sounds in the left & right surround channels are simply sent to the surround-back channel, without any active steering or cancellation. Unfortunately, that means any mono sounds in the surround channels will be heard from the sides and rears simultaneously, rather than only the rears.

Add to that the fact that PLIIx will generate stereo rears while CES sums to a mono rear, and the two modes shouldn't sound "very similar".

Best,
Sanjay

I've conceptualized a system that I call "Omnichannel." And I offer it here for free for all to pursue. (Call me the Linux of the home theatre world if you'd like.)

The system consists of an enclosure capable of radiating sound from an essentially infinite number of discrete point sources on its surface. It is also capable of holographically creating a sound point source anywhere within its enclosed volume.

Sound engineers are thus capable of taking any sound / effect and "placing" it on a three dimensional grid.

The system is fully adaptive and will sense the contents of its enclosed volume and adjust for them.

Just as it is able to create point source sound anywhere within its volume, it is also able to create point source lack-of-sound (nulls - but I call them non-audible black holes) as well. So you and your significant other could be in the same room together, you watching an explosive scene from T2 Extreme, while he/she enjoys peace and quite and the company of a good book.

Great sound and marital bliss. Gotta be a winning combo.

Until someone with deep enough pockets picks up on the concept and develops it, I'll just have to be satisfied with the entirely pleasurable sound coming from my model 950 - and not lose any sleep over how pathetically inadequate it will eventually be once Omnichannel hits the market.

Jeff Mackwood

Jeff, Except for your "non-audible black holes", everything else you described was developed 3 decades ago by Michael Gerzon. Ambisonics records and uses vector information to reproduce localization, rather than create it using pan-pot techniques.

Think of a drawing of a circle, stored as Bitmap vs vector. If you print large, the Bitmap image will suffer breakdown; you'll see the individual pixels and jagged edges of the circle. Not so with the vector drawing, which is a set of instructions on how to draw a circle, and will scale itself to any size print.

Similarly, Ambisoncis will scale itself to any size playback: 2 speaker to 5.1 speakers to 64 speakers to as many as your heart desires. The information is stored on 4 channels: main/mono, left vs right, front vs back, up vs down. If you just want stereo playback, you just need the first 2 channels. For surround sound, all the speakers locations can be extrapolated from the first 3 channels. If you want height information too, you can use all 4 encoded channels.

The Nimbus label recorded their entire catalogue of classical music in Ambisonics and Meridian processors have an Ambisonics mode for proper decoding.

Best,
Sanjay

Sanjay,

I'm sure that you noticed the tongue-in-cheek approach in my post - but yes I had some passing knowledge of past real-world attempts.

But to get back to my concept...it does not rely on "speakers" at all. Think of the enclosure as a continuous membrane that is able to produce sound at any point source. Perhaps an infinite number of pixels on a curved / complex surface would be a good analogy. As such it becomes not a 5.1, or 7.1, or even 16.1 system, but rather an infinite.infinite system - which is surely the natural culmination of adding more and more channels. My concept simply gets us there right away - and eliminates all those costly upgrades in between!

Jeff Mackwood

I'll buy that for a dollar! (as they say in Robocop)

Sanjay