Magnepan’s “Tri-Center” Concept: Does Stereo Sound Better with Three Channels?

Posted by: Chris Martens at 9:09 am, October 7th, 2011

The only caveat I would mention is that there was, at least during my first Tri-Center listening session, some shift in overall system tonal balance when the Tri-Center array was brought into play. I discussed this with Diller, indicating that I felt the balance shift was somewhat clouding my impressions of the benefits of the Tri-Center array. Diller replied that he had some Tri-Center tuning and set up ideas that might solve the problem and asked if I could return to Magnepan for a second listening session a day or two later. Since my flight scheduling allowed this, I quickly agreed and found that, on the second visit, Diller had successfully dialed in the system to a point where balance shifts between the pure stereo Maggie system and the Tri-Center system were very small, thus making the benefits of the Tri-Center even easier to appreciate than they had been before

 

How Does the “Tri-Center” Work?

The Tri-Center system, as shown at White Bear Lake, was powered by a very high-quality multichannel preamp/surround processor and a bank of beefy power amplifiers, all sourced from Bryston. When the system is played in conventional stereo mode, the Bryston pre/pro passes unprocessed stereo signals to the power amps and music happens. When the Tri-Center array is engaged, however, the Bryston’s surround sound processing circuits are brought into play. Incoming stereo signals are digitized (if they are not already in digital format) and routed through the Bryston’s Dolby ProLogic II processor, which uses a very specific set of Tri-Center configuration settings. The processor also manages time delay and bass management settings as necessary for the Tri-Center array (technically speaking, the Tri-Center is a “small” speaker, so the processor re-directs bass from the center channels to the left/right main speakers). The Dolby ProLogic II decoder creates the left, center, and right channels signals fed to the amplifiers and on through to the left/right 3.7 speakers and to the Tri-Center array. No rear or surround channels are used at all.

 

Conventional Wisdom is Wrong

Among audiophile purists, conventional wisdom would hold that less is more, that simpler signal paths always sound better than complex ones, and that two good channels will beat three channels plus a (gasp, choke, gag!) surround-sound processor—especially one with a comparatively humble Dolby ProLogic II decoder engaged. Now ordinarily, I would side with the purists on this point, but the simple fact is that conventional wisdom is wrong in this case. The Magnepan stereo rig as augmented with the Tri-Center array produced a sound that is arguably superior to the results achieved by traditional Magnepan 2-channel system (an extremely good system, by the way)—and without sacrificing any of the sonic qualities purists care about most. In fact, if anything, the Tri-Center array actually enhances some of those qualities, though never in an exaggerated way that would undercut musical realism.

Diller concedes that the Tri-Center concept may be too unorthodox to find widespread acceptance and that it probably won’t help Magnepan sell more loudspeakers, but his position is “it’s an idea that simply sounds so good that we just can’t keep it under wraps.” I’ll second that assessment and offer this bit of encouragement: if Magnepan ever brings the Tri-Center array to a trade show near you, do make a point of going to hear the system. At the very least, it should make one heckuva great conversation starter.

 

As It Turns Out, Great Audio Minds Sometimes Do Think Similarly

By the way, in case you are wondering, Magnepan is not the only company experimenting with something like the Tri-Center array. At the recent CEDIA 2011 show I had a chance to speak with none other than Richard Vandersteen about the idea of using three-channel systems to listen to stereo material. He explained that he, too, has done considerable research in this area, although his implementation of an appropriate audiophile-grade center-channel speaker is—as you might expect—quite different from Magnepan’s. Vandersteen told me that he often uses a three-channel configuration for his personal home music system, and that it can and does give impressive and musically satisfying results. Interesting, don't you think?

Comments

dlaloum -- Sat, 10/08/2011 - 18:44

 Nothing new there...
 
Stereo (by definition - coming from the greek word for "solid" so it is sound giving the illusion of solidity) - was originally invented in th 20's/30's as a 3 speaker system. - It is NOT contrary to popular belief and useage, related in any way to 2 channel sound. (In fact by extension, properly used multi channel surround systems are true "stereo", as they have a greater potential for achieving the illusion of solidity!)
Later developments worked on 2 chanel recording with 3 channel reproduction.
Macintosh receivers of the 50's and 60's were set up for three channel stereo.
Now that almost every home as 5.1 surround, and the most common media component is the multi-channel AVR - implementing 3 channel stereo reproduction is trivially easy... 
Finally we can start to hear stereo the way it was supposed to be heard.
Now if only we had more properly recorded Blumstein recordings....
 
bye for now

David

GEICKMEI -- Tue, 10/11/2011 - 12:40

Agreed, nothing new here. We should all be listening in surround by now, with at least a Dolby Pro Logic II decoder giving two channel recordings a center channel and the surround channels. What do they think they are doing by giving it a fancy label?

The insight to be had about using a center channel speaker is this: In setting up your two outside speakers, left and right, it is easy to get the center imaging screwed up. If you place the speakers too close to the front or side walls, you can get a clustering of reflections at each side that causes a perception of stretched soloists, a hole in the middle, imprecise center imaging. This is especially true with dipolar or omni speakers, but if you use directional speakers you will get even worse off-center effects. The center channel speaker covers up a lot of those errors and lets you sit off to the side without furrowing your brow. The beauty of it all is that you use the same system for both music and home theater. Set it up for home theater and you are good to go for music as well.

And David, make that Blumlein, not Bumpstead.

Josh Hill -- Wed, 10/12/2011 - 09:50

"What do they think they are doing by giving it a fancy label?"

Well, this is a different implementation of the center channel, which involves using both three speakers with specific dispersion patterns and processing which is apparently critical to the effect. The overall sonic effect is apparently quite different from that of a single speaker.

Matt Harris FB -- Wed, 10/12/2011 - 02:42

Hi David,

I'm always open to hearing new musical performers. Who is "Blumstein" and where can I hear him/her? I Couldn't find anything relevant to music on Google.

Thanks,

Matt
www.Liquiphonics.co.uk

dlaloum -- Wed, 10/12/2011 - 06:41

Heheh thank you guys .... a slip of the keyboard (and the memory)....

Josh Hill -- Sat, 10/08/2011 - 21:36

There's apparently more to the tri-center than just conventional 3 channel stereo, which Magnepan has long offered. Why that is, it seems no one knows, including Magnepan.
Amen to Blumlein! 
 
 

Jyoti Banerjee -- Tue, 10/11/2011 - 06:45

 In what way is Magnepan's Tri-Centre different from Trifield, say as implemented by Meridian?

Josh Hill -- Tue, 10/11/2011 - 07:28

Trifield is a method of deriving a center channel from a two channel source. Tri-center depends on the physical arrangement of three speakers to reproduce a derived center channel. They've been using a Bryston SP-2 pre-pro to derive the center, with very specific settings. Apparently, the effect doesn't work as well with other processors they've tried, for reasons that aren't entirely clear. According to Bryston, it doesn't work as well with conventonal monopole speakers, either. Not sure if anyone's tried it with a Trifield processor rather than a Dolby one.

Norman Varney -- Tue, 10/11/2011 - 13:11

Three front channels is especially nice with the new Living Stereo three channel SACDs!  A word of caution for three channel, unless conditions are just right, 2 channels will prevail over 3. Three channels require very accurate time alignment, matching of amplifiers and cables (not to mention speakers), encode/decode processing, and acoustic room treatments for first order reflections.
As in home theater playback, the CC can help solidifiy the stereo image for those off axis, but the money seat does not require it. Two channel, when produced well, reproduces superior to three, and does so without the added cost and complexity.
If I had my way, home surround sound would consist of R&L front, R&L rear and R&L front sub channels.

Norman Varney
A/V RoomService, Ltd.

Josh Hill -- Wed, 10/12/2011 - 09:45

I agree completely if we're talking about conventional three-channel stereo. But I gather from the reviews I've read, and from discussions with someone who's currently trying it, that the tri center is a real improvement.

Here's part of what he said in an email. Referring to conventional three channel with the Magnepan CCR alone: "The problem was that it was very easy to localize the CCR both from side to side and top to bottom. If there was a single voice (i.e. singer) in the music, the voice would be frozen on where the CCR was, nice but not very realistic." And referring to the tri-center setup, with the flanking dipoles balanced and with some delay: "At that setting, a vocalist floats very clearly in space in front of an orchestra, but the individual instruments in the orchestra are highly localized side to side and with a feeling of significant depth. The feeling is that the soundstage moved back away from the listener but added depth."

So I think we should keep an open mind as to what it can do until more people have had a chance to try it. The question I think being whether it's gotten three-channel stereo right and overcome the limitations which better suited the center channel to a role as an anchor for off-axis listening than to "sweet spot" music listening.

Monaco2000 -- Sat, 10/15/2011 - 10:12

I still love the old-fashioned "Hafler Hookup"---two Maggies in front of me, two Maggies behind me. The sense of realism is greatly enhanced. The rear speakers voice the difference signal off the recording---heard by the mics but never reprduced in conventional stereo. For those unfamilar with the Hafler Hookup, just Google it for lots of great info.

 Larry Forbes
Klee Acoustics

wessokolosky@ya... -- Tue, 12/20/2011 - 18:49

If I'm not mistaken, Bell Labs did a lot of research into 3 channel "stereo" music reproduction in the late 30s, perhaps the 40s, concluding that 3 was better than 2. That led Paul Klipsch to advocate 3 channels across the front as early as the 50s. (Dates may be a bit off as this goes back a ways.) Klipsch designed his LaScala/Belle Klipsch to serve as a center channel, way before the idea was widely adopted. The Bell Labs papers on the concept were available through Klipsch at one point.
 
Wes

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