# Dual Center Channel Speakers



## dbshelton

Has anyone tried using one center channel speaker above the screen and one below the screen? Seems like it would work well to me.


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## Kal Rubinson

dbshelton said:


> Has anyone tried using one center channel speaker above the screen and one below the screen? Seems like it would work well to me.


Some have found it useful. It has been discussed many times. Search/Google should reveal a lot.


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## Sir Terrence

I have always recommended against this practice, only to have others shoot me down. I would recommend just getting a larger center speaker rather than this approach as it is just acoustically easier to tackle. Anytime you have two spaced speakers reproducing the same output(mono), you are going to have subtractive and additive interference. EQ can be deployed to handle the issue, but that means equalizing in areas that you don't want to use equalization on(midrange and high end). It is just simpler to use a single larger speaker than this approach because you can preserve the midrange and high end from equalization, but still use it where it is most useful(the bass frequencies). I would imagine there would be some image smearing having two of the same signals arrive to the ears at slightly different times(there is no delay option to correct this with two center speakers). 

I have heard this kind of set up before, and it sounded decent. However the person who owned the system had to do a lot of EQ to correct some response problems from the interaction of the two speakers. 

There are easier ways to get a bigger sound from the center channel.


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## dbshelton

I decided to play with this today and from my little experiment, it actually sounds better to me with just the one center speaker. Two identical speakers was the worst, but with vastly different speakers it really wasn't too bad at all, but I don't think it is worth the trouble to make it work. I'm sticking with my home-built with the 2-Peerless 6.5" and Dayton silk tweeter. It's really not too shabby at all!


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## pmcneil

As I'm sure Sir Terry would agree, the ultimate solution is to mimmic the 'in theater' conditions, which are used for mixing.

In theaters, the centers are behind a sound transparent screen (I assume in the midline of this screen). OK, perfect.

But if, as in most home theaters, there is no sound transparent screen (but instead a TV or sound reflecting projector screen), then one one must rely on stereo, which can work well (or have I been 'out of it' for the last 30 years). In stereo, one can get imaging in the center from two speakers arrayed (both conventional vertical, not typical centers) one above and one below (I haven't tried one on each side, as this more or less duplicates my left and right speakers, AND, given the 16:9 screen ratio, this is an important variable, in deciding between above/below vs left/right). It works, with my Revel M20s. BUT it requires ceiling mounting of a speaker, not an easy thing (required three trips to Lowes, and many more with a drill up and down a ladder). WHO IS GOING TO SELL THIS SOLUTION! 

Otherwise, one puts up with a speaker that is sonically above or below the screen. And sensing this localization does not take 'stereophile' ears.

If you want the voices in the middle of the screen, get one that is sound transparent, or place two centers above and below.


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## Gregr

From personal experience I can honestly say that anytime I've tried something new that should add to the volume of air movement in the room it always sounds more dynamic. I used to get excited about volume and clarity and I was not alone. Look around 3.1, 5.1, 7.1 where is the end. 

If your listening room is theater size you may need more speakers. However for the listening room 12-14-16 x 16', to my mind there is not much sense in investing in more then 5.1 THX quality system and instead..., well, if as you sit in the prime seat you can pinpoint the sound as coming from this or that speaker or even which driver than improving the quality of your system is a much wiser investment.

As I sit in my favorite seat watching a movie or listening to music I can't tell you exactly where the sound is produced I can hear the difference between l/r in locating the source of sound. With sound like this movies are very believable. I am never taken out of the movie by sound that sounds like its coming from "that bad speaker" 

But for me I could not understand why audiophiles complained that you needed the finest 2 channel system for music and that the needs for movies was a whole other matter. And a Home Theater system would be a marginal musical system. 

I am happy with what I have but I am not satisfied I've achieved the best possible sound

Well before I decide to write a documentary on the topic...

Happy New Year :spend:

Greg


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## pmcneil

> But for me I could not understand why audiophiles complained that you needed the finest 2 channel system for music and that the needs for movies was a whole other matter.
> 
> Yes, exactly, as regards the center channel, eminating sonically from the CENTER of the screen, and not the floor!!
> 
> Seems, they get less picky...


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## dbshelton

I'm still playing around, trying different stuff to see what difference it makes in my bedroom theater setup. It's 17' wide and 14' deep and has heavy carpet, drapes, but drywall ceiling, and solid wood walls. Now I added another pair of Boston VRS surrounds and as for the center channel, I removed the Dayton silk tweeter and replaced it with a Klipsch horn tweeter I bought off Ebay that is an exact match for the tweeters used in my inwall Klipsch front speakers. That was a great move! It really brightened up the front center sound, but didn't lose any of the deep bass response that the Peerless 6 1/2" center speakers have. I even installed an L-pad to tone the tweeter down just a hair.
I'm not sure how the 4 dipole surrounds are gonna work, but I think I am gonna like it.


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## pmcneil

dbshelton, Experimentation is a good thing, given that room acoustics account for up to 50% of sound quality. Good luck! Paul


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## Sir Terrence

pmcneil said:


> As I'm sure Sir Terry would agree, the ultimate solution is to mimmic the 'in theater' conditions, which are used for mixing.


Bloody spot on chum! (gotta get my cousin's British accent out of my head)



> In theaters, the centers are behind a sound transparent screen (I assume in the midline of this screen). OK, perfect.


In middle of the screen, at about one third height of the screen. 



> But if, as in most home theaters, there is no sound transparent screen (but instead a TV or sound reflecting projector screen), then one one must rely on stereo, which can work well (or have I been 'out of it' for the last 30 years). In stereo, one can get imaging in the center from two speakers arrayed (both conventional vertical, not typical centers) one above and one below (I haven't tried one on each side, as this more or less duplicates my left and right speakers, AND, given the 16:9 screen ratio, this is an important variable, in deciding between above/below vs left/right). It works, with my Revel M20s. BUT it requires ceiling mounting of a speaker, not an easy thing (required three trips to Lowes, and many more with a drill up and down a ladder). WHO IS GOING TO SELL THIS SOLUTION!


Not only is it more difficult to set up, but there are acoustical problems with it as well. If you have a none transparent screen, then getting a matching center speaker under the screen is much better. Raising the screen so the bottom is at eye level will allow a vertically mounted center speaker under it. I did that with one of my setups, and a center speaker that stands 40" tall. It works great for a single row of seats, and when I need it to cover a second row(that is 6" higher than the first), I tilt it back just a little bit using a black rubber door holder. 



> Otherwise, one puts up with a speaker that is sonically above or below the screen. And sensing this localization does not take 'stereophile' ears.


I found that putting a speaker above the screen raises the height of the dialog to the point that I notice it being there. 



> If you want the voices in the middle of the screen, get one that is sound transparent, or place two centers above and below.


I would definitely recommend the former long before the latter. The latter requires far too much effort in physically setting it up, and far too much effort in measuring and correcting the response of the two separate arriving signal hitting the ears. It requires time delay for the two speakers, and two amps as well. Too expensive a troublesome when there is an easier solution.


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## pmcneil

I agree, Sir Terrance, that the best solution is a sound transparent screen (though what you put behind it is another question!). 

But how feasible, presently, is that, given the cost of these screens, and their limited format (I want one for less than $500, that I can mount on the ceiling and pull down by hand!).

Meanwhile, stereo (which as a previous correspondent indicated, was once nirvana) works with a vertical array, e.g. two conventional vertical speakers, one over and one under the viewing area.

Yes, this vertical array is difficult to set up, but that does not detract from its usefulness: it can fill in a space (center of the screen) while leaving the listener unaware of the location of the sources (above and below, rather than left and right). 

But, I am waiting for that affordable sound transparent screen...any suggestions, anyone?


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## GranteedEV

IMO if you're restricted to a TV or non AT screen then one great, dynamic centre is enough, but you must go with a controlled dispersion characteristic. 

Never have the center _well_ below you. The lowest I would go would be about 25 inches off the ground - this usually means the center must be as high as the top shelf of a TV stand with the TV raised up... the TV then is actually a bit higher just as Sir Terrence described. I have mine tiled down by about 10-12 degrees and it looks great. Initially I felt it may have been too high but after a short adjustment period it feels great. 

You don't want a horizontal MTM at all, and even a vertical MTM will probably interfere with your mains unless they're VERY widely spread apart (like 15 feet or so left to right). Unfortunately I'm actually stuck with a horizontal MTM as the TV is not mounted high enough for a vertical and I really chose it for aesthetic reasons (matcing the mains which I bought due to budget) knowing full well the consequences. 

My option, then would be something like the Gedlee, JTR, Seaton and JBL pro audio type stuff or perhaps the sort of layout seen with the Salk V3 Monster Center (although I question the success of a ribbon tweeter in this scenario)

If the center is underneath the TV, what you want to do is take away floor reflections as they will pull the image further down. I would go as far as to make a "first reflection point OC703 panel with a rug on top". As you may know, absorption will narrow the soundstage of a pair of speakers, so of course you're "narrowing" it in one direction here and pulling the image away from below you.

Next while on paper you may want to pull the image up with a quick first reflection off the ceiling, I don't quite know if I would go thier route. I would experiment with diffusion on the ceiling and see what sounds best.

Also angle the center up towards ear level (note this may pull the reflection points forward a bit.. adjust accordingly).


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## dbshelton

The way my bedroom is setup, I am looking up at the screen and the center speaker is below the TV but is also above me, to minimize the angles. My left and right front speakers are right at 12' apart. Works pretty well at this point. With this setup, it seems that the center speaker quality is more important than it is in my other setup in my living room with the front speakers closer to the screen. I have one pair of dipole surround speakers directly beside me on the side walls and another pair on the rear wall behind me. It really seems to "fill" the room when watching a movie with a lot of surround content.


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## dbshelton

I have always thought that the center channel speaker should be as good or even better than the front channel speakers but should all be compatible. 
In my Living room setup, at this time I have a Polk center channel speaker above the screen and a Bose center channel speaker below the screen. Tried a Yamaha that I had laying around, but didn't like the results. I know the Bose is not a match to the Polk, but they really sound very good together. I may even try another matching Polk, or maybe even the next larger sized Polk that is the same series as the front speakers to replace the Bose.


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## MikeBiker

I prefer one center speaker because it cost 1/2 as much as two.


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## dbshelton

MikeBiker said:


> I prefer one center speaker because it cost 1/2 as much as two.


Excellent point, but we always need an outlet to throw away more money. LOL!


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## rab-byte

If you are dead set on using two maybe instead think about getting a supper tweeter placed above the tv with the center at the bottom. That may bring your sound a little further up without needing to mess with too much EQ. 

Just a thought.


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## blatz

I just set up two different center speakers, stacked on top of one another, both being played from an Integra ADM 2.1 100x2 chan amplifier and it sounds great. Using my Denon AVR-X4300 as processor. Give it a try and see how it sounds. I have the smaller JBL center sitting directly on top of my huge infinity center speaker, both are directly below the TV on an entertainment center.


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