Yes I understand now.
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Using dual center channel speakers - Any downside?
- Thread starter 73hadd
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There was a user here that reported success with a "tri-center.". I'm not qualified to address the +/- directly but my instinct says if this were a good solution, it would have garnered enough popularity to be integrated in modern AVRs (or at least motivate Magnepan to update this page away from the Geocities design)
I am curious, how big is the screen and how far is the listening distance that this is an issue?
I am curious, how big is the screen and how far is the listening distance that this is an issue?
I’m aware of Magnepan’s Tricenter. I’ve never fully understood the third panel as the two side panels would seem to be enough - unless it is a matter of total output? Or perhaps the third panel ameliorates any combing of the two side panels?
It is interesting and even more interesting that people prefer listening to their stereo music with the tricenter active. Although Meridian has been doing Trifield for years.
It is interesting and even more interesting that people prefer listening to their stereo music with the tricenter active. Although Meridian has been doing Trifield for years.
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- Thread Starter
- #24
Also there is this description of the two panel MC1 (on either side):
www.magnepan.com
The interesting part to me is their description of how to keep the image centered. (Is this "time intensity trading?")
I have heard this center channel mono signal to two speakers one-on-each-side setup and thought it sounded great.
I am now confused about the previous comments in this thread about two center channel speakers playing the same signal as seeming to be against "speakers 101" and "comb filtering" as isn't that exactly what all stereo imaging is based on? The same signal existing on both L and R channels?
Maybe I described the original thread wrong as the intention would be to have them at least 2-3 feet apart and not right next to each other. (my clue was the 1/4 wavelength comment)
Listening to two speakers playing the same mono signal seems to sound pretty good, but again this is speaker spacing of >4ft.
Above and below the screen? I have not tried that.
@abdo123 My issue with the R2C is that it has the "neck" in the horizontal coverage response and is not generally better horizontal coverage width than a single speaker R3 etc, even though it's wider. So, a speaker on each side of the screen, is a lot of center channel information over a large physical area.
@LTig I never got around to the pink noise test, but I assume the comb filtering is mitigated by space between the speakers?
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I have heard this center channel mono signal to two speakers one-on-each-side setup and thought it sounded great.
I am now confused about the previous comments in this thread about two center channel speakers playing the same signal as seeming to be against "speakers 101" and "comb filtering" as isn't that exactly what all stereo imaging is based on? The same signal existing on both L and R channels?
Maybe I described the original thread wrong as the intention would be to have them at least 2-3 feet apart and not right next to each other. (my clue was the 1/4 wavelength comment)
Listening to two speakers playing the same mono signal seems to sound pretty good, but again this is speaker spacing of >4ft.
Above and below the screen? I have not tried that.
@abdo123 My issue with the R2C is that it has the "neck" in the horizontal coverage response and is not generally better horizontal coverage width than a single speaker R3 etc, even though it's wider. So, a speaker on each side of the screen, is a lot of center channel information over a large physical area.
@LTig I never got around to the pink noise test, but I assume the comb filtering is mitigated by space between the speakers?
FWIW, I was looking through this Atmos document the other day...
From page 50 onwards is a description of "additional" speaker placement. They mention left and right screen speakers (between 5 and 15 degrees) and left and right centre speakers (between 10 and 30 degrees).
I'm not aware of any consumer AVRs that support these, yet, but perhaps Storm / Trinnov already can. (See edit below).
Personally I would have thought that above and below the screen would have been a better solution though (perhaps with the upper one inverted so that tweeters are always as close as possible to the tv edge).
Edit: This from the Trinnov site seems to confirm that the Altitude32 would support these additional channels...
The Altitude32 remains the only AV Processor on the market capable of decoding and rendering Dolby Atmos Home content in its full 24.x.10 channel count.
It's been capable of doing so since 2015, years before competition.
From page 50 onwards is a description of "additional" speaker placement. They mention left and right screen speakers (between 5 and 15 degrees) and left and right centre speakers (between 10 and 30 degrees).
Personally I would have thought that above and below the screen would have been a better solution though (perhaps with the upper one inverted so that tweeters are always as close as possible to the tv edge).
Edit: This from the Trinnov site seems to confirm that the Altitude32 would support these additional channels...
Unique Decoding and Rendering
Dolby AtmosThe Altitude32 remains the only AV Processor on the market capable of decoding and rendering Dolby Atmos Home content in its full 24.x.10 channel count.
It's been capable of doing so since 2015, years before competition.
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Yes.
I am still curious as to the size of the screen and the listening distance? Depending on budget, a larger speaker might be a easier/better option. Reference 4c is still on sale 
us.kef.com
Reference 4c Ultimate Center Channel Speaker | KEF
Three-way centre channel speaker For movie lovers looking for total immersion, Reference 4c is the paradigm. For clarity, detail and emotional depth, it's a revelation. Available Finishes: Luxury Gloss Rosewood All KEF REFERENCE products are considered special order and are not available to be...
us.kef.com
All still in the planning stage - including the room. Not sure how that particular larger center will do anything but improve lower bass response - which to my knowledge wouldn‘t really help get the image up to match the LR height.I am still curious as to the size of the screen and the listening distance? Depending on budget, a larger speaker might be a easier/better option. Reference 4c is still on sale
Reference 4c Ultimate Center Channel Speaker | KEF
Three-way centre channel speaker For movie lovers looking for total immersion, Reference 4c is the paradigm. For clarity, detail and emotional depth, it's a revelation. Available Finishes: Luxury Gloss Rosewood All KEF REFERENCE products are considered special order and are not available to be...
I’m using in-walls so can’t “just try it”. At least not without a lot of drywall work.
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Why would it be a disaster?
Not as good as R3
No worse than having two voices inside your head screaming at each other, 24/7 every day for the rest of your life.
I have shared several comments on why that’s the case, feel free to read them.
I found that interesting also - a left and right screen speaker? And/or a left and right center speaker? I have to assume the former is for AT screens and the latter for Non-AT (or flat panel) screens. So the issue is being addressed. Wonder if any actual processing is done other than a dual mono center signal?
Speakers 101, never have two tweeters running simultaneously unless the distances between them is in the millimeters and they're all vertically aligned like a line array.
Also never have more than one mid-range unless they're also vertically aligned.
Came across these. They would seem to satisfy? Two line arrays side by side - one L/R housed next to a dual center in the same enclosure. Although perhaps not a solution for a proper theater, it is an interesting proposition for a secondary setup.
Speakers - Savant
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I posted this on a couple of other forums, as well another ASR thread, but I also wanted to post it here for discussion. One of the new specs being touted about the channel layout for the DTS-X Pro and IMAX Enhanced soundtracks is the 'Center Front Height' channel, and this has piqued my interest..
Many, if not most, home theater enthusiasts suffer from some sort of compromise when it comes to locating their center channel either below or above their screen, so this new spec surprised me and I'm wondering about it's potential implications.
From the small amount of info I've been able to find online about the purpose and function of the Front Center Height channel, it sounds like they decided to implement a sort of 'dual center channel' approach. There are a couple of YouTube videos where the Sound United guys talk about the speaker layouts for IMAX Enhanced and DTS-X Pro (and Auro), and the IMAX theater screens were mentioned as the original motivation for their need to implement 2 center channels, because the IMAX screens were so large. That concept then got adapted for the home environment and they mentioned using this new Front Center Height channel as simply another discreet speaker in the setup, and that it used phantom imaging between it and the other speakers nearby (L / C / R / and Wide spkrs) to better lock the sound to the screen.
Historically, the dual center channel approach has been frowned upon because of the potential for comb filtering, lobing, phasing and other negative side effects. The forums and threads covering this topic mention one reason for why doing dual center channels was a bad idea, and that was 'if it was so easily done and such a reasonable approach then one of the big companies would have done this and just added a 2nd discreet center channel above the screen'. It seems to me like this may be what has happened here with the CFH channel approach by IMAX and DTS.
I may very well be wrong in my interpretation of this channel's use, but I'm curious what everyone's thoughts are about it and it's potential, considering that it would solve the center channel localization problem that so many people have.
Many, if not most, home theater enthusiasts suffer from some sort of compromise when it comes to locating their center channel either below or above their screen, so this new spec surprised me and I'm wondering about it's potential implications.
From the small amount of info I've been able to find online about the purpose and function of the Front Center Height channel, it sounds like they decided to implement a sort of 'dual center channel' approach. There are a couple of YouTube videos where the Sound United guys talk about the speaker layouts for IMAX Enhanced and DTS-X Pro (and Auro), and the IMAX theater screens were mentioned as the original motivation for their need to implement 2 center channels, because the IMAX screens were so large. That concept then got adapted for the home environment and they mentioned using this new Front Center Height channel as simply another discreet speaker in the setup, and that it used phantom imaging between it and the other speakers nearby (L / C / R / and Wide spkrs) to better lock the sound to the screen.
Historically, the dual center channel approach has been frowned upon because of the potential for comb filtering, lobing, phasing and other negative side effects. The forums and threads covering this topic mention one reason for why doing dual center channels was a bad idea, and that was 'if it was so easily done and such a reasonable approach then one of the big companies would have done this and just added a 2nd discreet center channel above the screen'. It seems to me like this may be what has happened here with the CFH channel approach by IMAX and DTS.
I may very well be wrong in my interpretation of this channel's use, but I'm curious what everyone's thoughts are about it and it's potential, considering that it would solve the center channel localization problem that so many people have.
DavidMcRoy
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I have been using the Magnepan Tri-center technique for a few years and I remain very happy with it. I did it with a pair of old SMGs on either side of a 96” projection screen and currently a 65” LED panel, and the MGCC3 mounted in free space over the screen. Main left and right speakers were 1.6/QRs. I‘ve also done it with all JBL 305P MKIIs (see attached photo) and with all Adam Audio T5Vs across the front instead of Magnepans. In every case, each speaker was EQed and level- and delay-coordinated with DSP. The results were great in every case. I settled (most decidedly) on the 3 center speakers being time-aligned with each other and the “center center” doing about 95% of the work, using only the “side centers” to tweak vertical and horizontal phantom center image position. The added subtle sense of spaciousness from the decorrelation effects of low-level comb filtering is a pleasant side effect if you have become accustomed to it from decades of two-channel stereo like me.
If you try any of this without DSP control, you may become very quickly frustrated. With DSP and some patience and time you can dial things in pretty tightly. You get a fairly stable phantom center image wherever you want to place it.
Note that a pseudo tri-center effect can be done by feeding a tiny bit of the center-channel audio into the front main left and right speakers instead of using dedicated “center-side” speakers. Indeed, some surround presentations are already mixed that way. My background is in television broadcasting where that’s quite common, though not universal. Having dedicated ”center-side” speakers as a sort of luxury seems to yield better results. I could speculate about a handful of reasons why.
I have also experimented with the center speaker of the tri-field array below the screen, but floor interactions drove me crazy. I’m less bothered by ceiling interaction, I guess. I even tried “over and under screen” centers with no ”side center” speakers with Magnepans and with the little JBLs. In both cases, disaster ensued, again probably for a variety of reasons.
Things are a lot easier with the box speakers because of their simpler constant directivity radiation geometry. Doing “anything” with planar speakers like Magnepans is challenging because room interaction is so hard to compensate for. Notheless, once I get all 9 of my Maggies factory refurbished and we’re moved into a new house, I’ll return to that love/hate relationship. This is a Dolby Atmos system, and the height speakers will continue to be Adam Audio T5Vs. I can only take on so much.
One more insight: if you’re struggling with just a single center-channel speaker integrating with the rest of your system, try this: spend a few minutes listening to “just” the center-channel speaker, everything else muted. Is the “image” truly centered and stable? You may find that it isn’t! If it isn’t, assemetrical room acoustics are screwing things up. I can’t emphasize this enough. Try to fix the room as best you can, and be aware that going to a tri-center approach does offer the means to fudge some compensation for the problems with level and EQ adjustments to the “side-center” speakers, allowing you to “steer” the phantom center image to where you want it to be. That’s the magic behind the illusion.
If you try any of this without DSP control, you may become very quickly frustrated. With DSP and some patience and time you can dial things in pretty tightly. You get a fairly stable phantom center image wherever you want to place it.
Note that a pseudo tri-center effect can be done by feeding a tiny bit of the center-channel audio into the front main left and right speakers instead of using dedicated “center-side” speakers. Indeed, some surround presentations are already mixed that way. My background is in television broadcasting where that’s quite common, though not universal. Having dedicated ”center-side” speakers as a sort of luxury seems to yield better results. I could speculate about a handful of reasons why.
I have also experimented with the center speaker of the tri-field array below the screen, but floor interactions drove me crazy. I’m less bothered by ceiling interaction, I guess. I even tried “over and under screen” centers with no ”side center” speakers with Magnepans and with the little JBLs. In both cases, disaster ensued, again probably for a variety of reasons.
Things are a lot easier with the box speakers because of their simpler constant directivity radiation geometry. Doing “anything” with planar speakers like Magnepans is challenging because room interaction is so hard to compensate for. Notheless, once I get all 9 of my Maggies factory refurbished and we’re moved into a new house, I’ll return to that love/hate relationship. This is a Dolby Atmos system, and the height speakers will continue to be Adam Audio T5Vs. I can only take on so much.
One more insight: if you’re struggling with just a single center-channel speaker integrating with the rest of your system, try this: spend a few minutes listening to “just” the center-channel speaker, everything else muted. Is the “image” truly centered and stable? You may find that it isn’t! If it isn’t, assemetrical room acoustics are screwing things up. I can’t emphasize this enough. Try to fix the room as best you can, and be aware that going to a tri-center approach does offer the means to fudge some compensation for the problems with level and EQ adjustments to the “side-center” speakers, allowing you to “steer” the phantom center image to where you want it to be. That’s the magic behind the illusion.
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Soundmixer
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Try aiming the center channel upward so its center axis is aimed the same as the L/R speakers.
Not necessarily. I would not place my center high up on the front wall if my L/R mains were closer to the floor - that would certainly create this effect. Assuming the L/R mains are closer to the floor, I would locate my center under the screen and tilt it upwards until its center axis agreed with the L/R mains. This would ensure there is no roller coaster panning across the frontal soundstage.
