First post..need some advice.

[SopRage]

I will say that a pair of CMT-340SE's with a CMT-340SEc (horizontal center) will tonally match, and will give great performance in a 40 degree wide listening area.

Agreed; that's my recommendation as well (still).

 

[GranteedEV]

http://www.audioholics.com/education/loudspeaker-basics/center-channel-speaker/position-of-the-center-channel

Look. nothing is 'wrong' with gene's article but what you neglect to mention is the ridiculous money thrown at his 'acoustically treated' room.

in 95% of rooms you hear the reflections of the different off axis response as well as the very different cieling and floor reflections of an mtm. most of how we perceive sound is not just the initial wave that a mic pics up but also the early reflections and late reflections.

So No a horizontal CMT340 will not tonally match unless you eliminate all reflections (in effect also taking away some of the ambience of a recording). Its room intoeraction will be night-and-day different because the reflections will be notably different resulting in a vastly different timbre. Off axis response is not purely what someone hears if they are sitting off axis... this is not a laser beam of sound, nor do we want it to be.

Funny gene should use an RBH MTM in that article. my EMP e5Ci designed by the exact same people doesnt even sound close to the "matching" EMP e55tis; although between tuning it out and using audessey i can "mitigate" the facts. And just because alan loft or shane rich tell you that "you cant hear comb filtering" with two or three tweeter designs does not automatically mean you can not. They chose their design tradeoffs but that does not tangibly prove a thing. If something is good in theory it's good in practice. If something is bad in theory then you can ignore it in practice but that does not make it desirable. And if other options exist at a price point WHICH THEY DO then I think it's ridiculous to settle for mediocrity.

Besides the revel C12 I mentioned, anything with a reasonably flat on/off axis response +/- ~2db should work. A few these include

-A VERTICAL CMT-340 if you can put it behind an AT screen
-Infinity PC350 (maybe use EQ to tone down the high end just a tad to match tonally)
-Emotiva ERM-6.2 (should work nicely)
-Aperion 5C

If any thing is "overstated" it's not MTM centers, but Timbre match by using the same drivers.

 

[cschang]

Are you saying a C12 will timbre match a vertical CMT-340 better than a horizontal CMT-340?

 

[GranteedEV]

Are you saying a C12 will timbre match a vertical CMT-340 better than a horizontal CMT-340?

In a blind test, I would make the wager that the former combo would sound more coherent and natural than the latter choice. Neither would be as great as a vertical CMT-340 with each three front stage speakers spaced very widely (like ~10-12 ft from left to right)

 

[cschang]

In a blind test, I would make the wager that the former combo would sound more coherent and natural than the latter choice. Neither would be as great as a vertical CMT-340 with each three front stage speakers spaced very widely (like ~10-12 ft from left to right)

So, I would take that to be a "yes"?

How do we act on that wager?

Are you familiar with these quotes?
"They didn't care that they'd seen it work in practice because they already knew it couldn't work in theory."
“the distance between theory and practice is always so much smaller in theory than in practice”
“in theory, there is no difference between theory and practice; In practice, there is”

By the way, I am not saying that your are wrong. I'm saying you are wrong by using absolute terms.

 

[GranteedEV]

So, I would take that to be a "yes"?

How do we act on that wager?

Are you familiar with these quotes?
"They didn't care that they'd seen it work in practice because they already knew it couldn't work in theory."
“the distance between theory and practice is always so much smaller in theory than in practice”
“in theory, there is no difference between theory and practice; In practice, there is”
h
By the way, I am not saying that your are wrong. I'm saying you are wrong by using absolute terms.

your implication is valid. i would take a good mtm center over a poor wtmw center. there's many factors. but im not talkimg about theory here. theory is what gene's article discusses - in a completely controlled acoustoc environmemt.

i am talking about my experiemce here and correlating that with theory. which 'absolute term' did I use which makes me wrong?

Anyways im not really interested in making a poimt. you addressed my concerns about the cmt340 horizontal as being overstated and i respectfully reiterate that they aren't. you feel that having the same line of drivers is what is most important (theory) rather than well designed speakers with more optimal polar response (theory) then it is what it is. we have both put our opinions out there for op to consider. if practice is what matters then my recommendation would be that OP gets both the revel and ascend centers for in home trial and return the one which sounds less coherent after a level-matched comparision. of course in that scenario other biases still show up (aesthethic, financial) but that is the reality of any purchase. it is what it is and perhaps my suggestion isnt even worthwhile to consider. i still stand by my position.

 

[cschang]

All the OP has to do is try and see what works better for him.

We can talk theory all we want, what counts is what happens in practice.

I may be biased, but I have yet to read any problems with lobbing and the 340. In fact, the only time I have read about any problems related to off axis and a horizontal speaker was with an Axiom center.

 

[sholling]

like i said, a pair of cmt 340s with a revel C12 centre. should tonally match well and give great performance.

Sounds like a bigger compromise than a matched MTM center to me.

 

[SopRage]

David Fabrikant himself discussed why he chose the MTM design, and specifically why he did NOT choose a M-TM-M design for the CMT-340 on the Ascend forums.

Not sure if it's kosher to post a link to another forum.

As you can imagine, his response is that he chose the compromises involved in the MTM design over a M-TM-M design (and explains what the weaknesses are in each). Ultimately, it sounded like both are fine as long as you stay within the 20-degree horizontal window.

Just another perspective (from someone far more knowledgeable on speaker design than I am).

 

[roque1128]

Wow I didn't mean to spark such a big debate! Thank you everyone for your input and advice first this isn't a dedicated room unfortunately. It is a main living room that is open to the kitchen. Aesthetically I can not have a vertical center. I can see the argument both ways. Next year when my garage is re-modeled into a dedicated room it will be more of a consideration to have all three fronts and possibly rears identical. But for now I have to make trade offs and I think the 340's both mains and center will be just fine for the current application. I am not in any way opposed to high end(trust me), but just not for this set up. I just want the best possible sound for my money without breaking the bank And for those wondering, for the garage turned into the dedicated theater, I am looking at Snell acoustics for the audio with separate amplification for each channel, room treatments, basically all out. But I am still at least year to a year and half out on that project Thank you everyone for your replies so far.

Roque

 

[sholling]

Wow I didn't mean to spark such a big debate!

We're always debating how many angels can dance on the head of a pin. It's not a hobby it's an obsession.

 

[roque1128]

I would have to agree with you

 

[3db]

There has only been one mention of it previous to your post, and it was only stated as a personal preference as well. I don't know if I'd call it blown out of proportion. Well, TBQH, I personally wished I knew of the compromise with a horiz MTM before I bought my Images. At the very least I would be cognizant of the compromise I was making. I've been told that my C60, based on xover and driver spacing, would be 180 degrees out of phase at about 20 degrees off axis.

I'm trying to understand the physics behind that statement. A wave front is a wave front and I fail to see how it changes with respect to on center. If I look at a wave travelling towards the sand, I still see the crest as a straight line whether or not I'm looking at it dead center or from a 90 degree angle or from a 180 degree angle.

 

[jostenmeat]

I'm trying to understand the physics behind that statement. A wave front is a wave front and I fail to see how it changes with respect to on center. If I look at a wave travelling towards the sand, I still see the crest as a straight line whether or not I'm looking at it dead center or from a 90 degree angle or from a 180 degree angle.

The issue is that there are two crests from two points, because there are two drivers. A key part of the issue is that these two drivers are playing the exact same thing. So, when you are directly onaxis, these two drivers are equidistant from you, and everything is dandy.

Once you get off axis, these two drivers are now at different distances to you. Depending on the exact angle off axis you are, and the characteristics of the speaker itself, you will have a specific set of frequencies that will be cancelled and/or boosted.

So, one of at least the two concepts I offered in a better horiz MTM design is closer driver spacing. The reason is because when you are off-axis the "differing distances" are reduced, if that makes sense.

The second concept of lowering the xover point is so that there is so that less material being played by the two mid drivers simultaneously. If this xover point is low enough, then we won't even really discern the lobing effects. This is the main benefit of a WTMW over the MTM. See, the tweeter is above the mid (only one mid, btw), and woofers are xover'd low enough where when they are lobing, we can't tell.

The other commonly offered design for a center speaker is with coaxial drivers, that you often have seen with KEF. I have recently learned from TLS Guy, if I understood correctly, that the waveguide effect of a coaxial driver is often beneficial so that the dispersion pattern does not interfere too much with the mains, and most particularly when they are closer than they all should be together. I think it's something like that, but he can better explain.

 

[jostenmeat]

This is getting ridiculous. If we want "great" (meaning uncompromised) we're no longer looking at systems in this price-point. Everything is only "good enough" until you have the top product conceived of and produced by man.

The poster is looking at 5.0 systems around $1500, not outfitting his private screening room with a high-end flagship system.

This is turning into a theoretical exercise rather than offering real-world solutions. If there is a better system for the price (that does not feature the godless sonic abomination that is a MTM-designed center), let's simply offer it for the OP's consideration.

What is wrong with a theoretical exercise, especially when it's already been implemented hundreds of times by enthusiasts?

There are crazy expensive systems that use a horiz MTM, and there are affordable systems that use three identical vertically arrayed speakers.

If we didn't care about improving our systems, why would we be wasting so much time on these boards?

I have often recommended 5x identical speakers to people on low budgets, and often for speakers that cost less than any Ascend (perhaps outside of the HTM200, but even then). Such a configuration would work well when the room is small or that the viewing distance is small, and that offaxis listening angles might be great. Very often a "matching horiz center speaker" costs more, proportionately with many brands. I could overreact and say, why would you want to pay so much more money for a horiz center speaker?

Shoot, my newly implemented vertical tower center speaker cost me about the same as the matching horiz center it replaced. You could in fact say it was less money, since there is a second speaker in the pair that I could use for back up parts I suppose.

I would happily take a horiz MTM from Ascend over many TM speakers from many other brands. However, there is nothing wrong at all in stating that a vertically oriented speaker is ideal. Or, I would happily take a vertically arrayed Ascend over a horiz MTM Ascend over many other brands of vertically arrayed speakers.

Anyways, combining the idea of the goal of having vertically arrayed speakers with only having the top product conceived and produced by man is a just a bit much of an overreaction.

 

[jostenmeat]

All you need for the IDEAL setup of three vertically arrayed identical speakers on the same plane, all at ear level, all unencumbered by resonating and diffracting furniture . . .

A $20 Monoprice wall mount for your flat panel.
A $25 very long HDMI cable from Monoprice (that'll get you at least 40').
A $75 URC RF remote system.

Now, put your components anywhere else in the room, closet, place, wherever. Ta da.

I don't think $200 is considered OVER THE TOP. Oh, so you don't like how it looks? Well, I hope you don't mind offending Bose owners in the future with any statements as to what is ideal.

 

[cschang]

All you need for the IDEAL setup of three vertically arrayed identical speakers on the same plane, all at ear level, all unencumbered by resonating and diffracting furniture . . .

A $20 Monoprice wall mount for your flat panel.
A $25 very long HDMI cable from Monoprice (that'll get you at least 40').
A $75 URC RF remote system.

Now, put your components anywhere else in the room, closet, place, wherever. Ta da.

I don't think $200 is considered OVER THE TOP. Oh, so you don't like how it looks? Well, I hope you don't mind offending Bose owners in the future with any statements as to what is ideal.

But then this introduces the issue of proper height for the flat panel.

If you put all the speakers at ear level, this will force the bottom of the flat panel to be above ear/eye level. Proper ergonomics is to have eye level fall in the bottom half(some say bottom third is better) of the panel.

Yet, another decision for compromise.

 

[jostenmeat]

But then this introduces the issue of proper height for the flat panel.

If you put all the speakers at ear level, this will force the bottom of the flat panel to be above ear/eye level. Proper ergonomics is to have eye level fall in the bottom half(some say bottom third is better) of the panel.

Yes, this will depend on viewer distance, and height of viewers eyes. The display size is key. I should have said for "many common systems". A 65" plasma could be too big or too high if you sit say only 8' away, and you want to put it above a tower. However, a 50" from 15' away, I do not think the video compromise would be significant, at all.

edit: my main point is that equating the idea of having a vertically arrayed speaker to only having a flagship system is a great overreaction IMO. My example build with $120 in material will cost less than most AV furniture. The identical vertical center will often be less money than the horiz version. So, it is not forcibly about spending more money, and in many cases, it can easily be less money.

 

[cschang]

Yes, this will depend on viewer distance, and height of viewers eyes. The display size is key. I should have said for "many common systems". A 65" plasma could be too big or too high if you sit say only 8' away, and you want to put it above a tower. However, a 50" from 15' away, I do not think the video compromise would be significant, at all.

edit: my main point is that equating the idea of having a vertically arrayed speaker to only having a flagship system is a great overreaction IMO. My example build with $120 in material will cost less than most AV furniture. The identical vertical center will often be less money than the horiz version. So, it is not forcibly about spending more money, and in many cases, it can easily be less money.

Have you seen the screen sizes vs viewing distances the "video" guys advocate?

BTW..the same goes with the speakers. The farther you are, the angle in relation to ear height decreases.

Your point is well taken. There are economical ways to get around issues, but you have to pick your battles.

 

[jostenmeat]

Have you seen the screen sizes vs viewing distances the "video" guys advocate?

I'm one of them!