2+2+2 Multichannel


I just bought two DVD-A discs put out by a German Audiophile recording outfit called MDGD. They use the six available channels differently.

They use the Left and Right, Front and Rear channels in the usual way. But then they call for two additional front speakers, located above and outside the regular front speakers. These are driven by the Center and Subwoofer channels. It is all supposed to produce a "3-dimensional" sound field, with no particular "sweet spot" for listener location.

I have not yet had the time to jury-rig this setup. The printed material that came with the discs does not provide much in the way of description of this 2+2+2 scheme. Does anyone out there have any info?
eldartford

Showing 5 responses by eldartford

Flex...Thankyou...I have enough amps and small but decent speakers to try this out. Alas, my room does not have a high ceiling. Someday I will build a large room with cathedral ceiling where my Magneplanar speakers can be suspended well off the floor: a setup that I have always liked.

If this kind of 6-channel speaker configuration were to become common my bigest problem would be figuring out how to switch back and forth between normal 5.1 multichannel and 2+2+2.
It seems to me that above the fronts would likely be the best place for "height" channels. However, I am all bent out of shape about loosing the center channel, which I have always considered most important, even for stereo, where it is easily derived from ther 2-channel source.

I don't know why the center channel speaker gets such criticism in audiophile circles. Examination of the signal characteristics of stereo recordings will show that common-mode modulation dominates, and this is center material. In particular, solo performers are usually recorded equally in both channels, and isolate nicely in the center channel. I know that two good speakers will image the soloist between them, but this effect depends stronly on listener position, which is not the case where a center channel speaker is used. Other advantages are a wider soundstage because the left and right speakers can be further apart, and reduced speaker power for a given room sound volume level. Of course it goes with my philosophy that the center speaker and amplification should be as good or better than the left and right. Perhaps the minimalist center channel speakers that are commonly used for movie dialog may be responsible for the bad rap for music.
Unsound...Although a discrete center channel signal is best a logic-assisted matrix center channel can be darned good. Getting four channels out of two was too much to expect, but three out of two is quite reasonable. My surround sound processor has a 3-channel mode which I use when playing 2-channel material. Of course this involves digital processing, but when I am already working with digital inputs from a CD I don't see this as a problem. Although I have not heard it there is a purely analog three-channel decoder available.
http://www.sedonaskysound.com/trinaural_processor.htm
Unsound...For matrix multichannel, very few recordings work well, and you probably never heard them. It's easy for me to understand your skepticism. Also, note my comment that it's a lot easier (and better) to get three channels out of two than four.

One of the best, IMHO, was not advertised as multichannel.
It's the LP version of Judy Collins singing "Amazing Grace". (The CD version is not so good). Judy is solidly front and center while a church congregation is around you. When it ends, as the reverberance dies away, you can hear people behind you putting hymn books back into the wooden racks. Scary! On the same record is "Farewell to Tiwathe" (a song about whaling) where the recorded sound of whales float all around the room while Judy sings. You are underwater with the whales!

You could check this out by just bridging your stereo amp with a couple a odd speakers in series (to keep the impedance up).

I don't know how well I can evaluate the 2+2+2 scheme, as my regular speakers are Magneplanars, and it just isn't possible to mount a high speaker above them exactly as specified for 2+2+2. I am going to give it a try with some box speakers, but the results may be inconclusive. Also, I am looking into the possibility of stacked MMG magneplanar speakers. (See other thread). For evaluation of the 2+2+2 scheme I think that a set of the tiny Bose cubes (yes, those)would be best. Remember we are evaluating the spatial effects, not audio quality, and the tiny size would facilitate optimum positioning and should help make the difference vs 5.1 apparent.