SVS MTS Family - Page 3

Because doing it right involves a different design--a three way, a coaxial, a vertical two way (B&W 700 series) etc--and that probably involves more money.

Think about it, if you're a company like Ascend and you already make a vertical MTM, I would have to assume it is much more cost effective from a production standpoint to simply lay it on it's side, tweak it, and sell it as a center channel.

What you end up with is a design that the manufacturer decides is "good enough".

My point from the beginning was that for the same money, you can find better center channel speakers.

It also involves marketing products that consumers will buy. It doesn't matter how technically sound or how good a product is, if your target consumer will opt not to buy your products because it doesn't fit their budget, room constraints, aesthetic appeal, or placement constraints. One of the biggest reasons that you find center speakers in a horizontal MTM configuration is that consumers want to fit their center speakers in the space available, either above or below the TV or in an entertainment center. From a physical dimension standpoint, this configuration makes sense to consumers, and therefor manufacturers will make every effort possible to try to make it work. It may not be an ideal arrangement from a technical standpoint, but as long as consumers continue to demand this type of setup, the manufacturers will find ways to make the compromises work.

You're right. But going horizontal doesn't mean it has to be MTM.

Only if you like to sit outside the lobe. If you're inside the lobe, a horizontal MTM is not a problem at all. If you get the crossover low enough, and the center-to-center distance between the midwoofers small enough, then the wavelength of the highest frequency that the midwoofers reproduce is large enough that the distance between the two guarantees no audible interference within a specific listening angle. Thus, if done right (low crossover, small distance between), a horizontal MTM works just as well as an WTMW for the large majority of environments. Sure, it's a compromise, but so is an WTMW (another driver to integrate). It's not that tricky folks, it works.

I think the best thing to do is, hold judgement until the product comes out.

The center lobe issue is a huge red herring. With all of those early reflections off the floor and ceiling, response (as well as dialogue intelligibility and stability of center image) is indelibly corrupted at every listening angle. It might sound fine to people who don't know better, true. But that only proves that some people haven't heard good speakers.

Moreover, those off-axis signals matter too, because the soundfield at one's ears is not just the pure frontal lobe except in an anechoic chambers. Refections of massively different sonic character from the on-axis radiation muck everything up considerably.

Don't believe me? How about some measurements of a toppled MTM on-axis and off. I don't have such a beast - all of the speakers in my home are either coincident or Dual Concentric designs of properly controlled directivity - would never ever considering such a beast get near my ears or pollute my measurement setup, so I don't - and won't - have measurements to show you. But Stereophile does.

Here's an Infinity toppled MTM. (Yes, it uses odd drivers. But if you think a small startup like SVS has more chance of optimizing any design than the Harman of Dr. Floyd Toole and Sean Olive you're kidding yourself.)

Here's a toppled MTM center from another long-time designer and manufacturer of full-range speakers, with long experience and expertise in driver and system design on the very highest possible level, Tannoy. The drivers, spacing, and offset are similar to this forthcoming AVS system, though Tannoy doesn't bother to brag about buying an expensive tweeter as all of their drivers are specifically designed in house for their own systems. So it should be considered as well-optimized as a toppled MTM can get based on topology. Does this center have a shot in hell of sounding good?

Much as I adore Tannoy's dual concentric based speakers, this set could not be more of a turkey. And if anything, this center will perform better than the SVS one because the small tweeter allows closer center-center spacing for the midwoofers.

And sorry, bragging about overspending on the tweeter in a fundamentally flawed design at the expense of doing actual design work does not fix the issue.

Yes, we know how to alleviate or diminish the problems.

Yet, except for tweaking the crossover, most manufacturers still offer you a "toppled" MTM, with no real effort made to offset the tweeter and squeeze the drivers closer together. Many simply offer a "toppled" version of their vertical MTM.

Here's another Stereophile measurement of a hopeless and worthless (i.e. toppled MTM) center channel, this time Focal's $5k (likely more today) Utopia Be Diva.



Note mostly how well the off-axis response tracks the main response. Anyone who doesn't think that will be audible whilst prattling on about the audibility of amps or wires should be considered in the grip of some massive delusions.

Hopefully AVS members will be attentive enough to notice that the off axis response curves on those graphs are at 45 and 60 degrees off axis -- and to read the article through to it's conclusion.

Your comment that first reflections can interfere with intelligibility is correct, although in most residential rooms the path length differences are not that significant. Your implication that because significantly off axis frequency response is not as smooth with horizontal arrays, that the first reflections of this uneven response will ruin the listening experience, is easily disproved by countless owner experiences and many professional reviews. And treating first reflection points helps all systems sound better.

Not that I disagree with your theory -- a point source is the best solution. Your physiology seems to be especially sensitive to 'time smearing' -- I happen to be especially sensitive to intermodulation distortion. Why don't you redesign the Altec 604G using modern materials and techniques?

ggunnell...thanks for pointing that out.

To put things in perspective, at 10 feet from the speakers, and 45 degrees left and right, it would put you 5 feet off axis at the listening position. 60 degrees, about 7.5 feet off axis(someone correct my geometry....it has been a while.) Also take note at how far apart your mains would be.

These articles, like everything in the audio press, don't have anything put purple prose in the text section. The measurements are the only thing of value in any audio rag.


Then we're in agreement that the critical listener will perceive a wildly awful frequency response from these things due to early reflections?


Not "not as smooth as the on-axis response," mind. Wildly different.

And the assumptions that the response everywhere except for dead center are more like the immediate on-axis response than any angular variation of it are, frankly, stupid.

And the only thing your last sentence proves is that many reviewers are tin-ears and countless owners haven't bothered to seek out better solutions.


IM distortion in coaxes is a bit of a red herring. It is trivially addressed to the point of irrelevance by using larger drivers (I employ a nearfield setup with 12" dual concentrics, for instance) that have to move less, and by steep highpass crossovers to limit excursion.
But I'm not advocating coaxes as the only way here, just one potential option that works reasonably well and has aesthetic benefits over some of the others at possible sonic costs. From a technical perspective, I'm not at all convinced that a coax is a better solution than an separate MT with a waveguide-loaded tweeter to even out the polar/power response in the midrange.

All I'm saying is that any speaker that has poor polar or "power" response is not worth of consideration. Toppled MTM centers are the absolute worst, but any speaker that puts the tweeter on a 180deg horn - i.e. a flat baffle - pays no attention to the directivity mismatch between the midwoofer at the top of its passband and the tweeter at the bottom of its passband is in my view unacceptable as well. In all honesty, attention to this kind of issue is what separates those who are capable of critical listening from those who may as well buy Bose.

And there already is a kind of modern take on the Altec 604G, the BMS 15M682. Also, the driver used in the Avantgarde Solo may be thought of as such a thing.

No -- we're in agreement that you do in your room Seriously, you are making a great case for folks to try to reduce first reflections -- in any system. Most tweeters have poor off-axis response -- what makes it even tougher is that untreated room surfaces have various reflectivity vs. frequency, so even if you could radiate a perfect polar pattern at all frequencies, in a typical room you are going to end up with uneven FR in the reflected sound.

One consequence of this is the design theory that you are better off using "controlled dispersion" (narrow pattern drivers) to reduce nearfield reflections to a minimum. This works well until someone who has a real Home Theater, and needs a wider coverage angle, comes along. If you are in this category, check the off-axis frequency response before you buy.

Most of the rest of your subjective comments boil down to the fact that you need more radiation pattern control at the driver than most of us do. For most folks, the basic set of room treatments is enough to solve the uneven reflected FR problem and the reflected arrival time problem.

When Tymphany makes a 6 1/2" coax that can be used in popularly priced fit-into-existing-furniture centers, we'll see what happens

Moving on (hopefully) -- has anyone heard this new ScanSpeak D-3004 tweeter?
Has anyone reviewed a system using it?

The original one around here (that's why I was asking - tongue in cheek of course)

I'm kinda curious if anyone knows any more reviews about the d3004-6600, I'm currently just mesing around thinking about updating speakers etc, this looks rather interesting although I've had my eye on some onix strata minis. Doh.

Absolutely not. I've never had such a poor speaker design in any "my" room, nor will I ever. I am speaking in the general case, applicable to your room much more than mine, as you are apparently more willing to be an apologist for fatal sonic flaws than I am.


Actually, the truth is exactly the opposite, that controlled (narrow) directivity speakers offer the second widest possible listening area, after controlled (omnidirectional) directivity speakers. Let's take the following setup as an example: three speakers of 90deg controlled directivity with a smooth but marked treble rolloff beyond that point, placed with the acoustic centers of the L and R speakers 12' apart with the acoustic center of the C exactly in the middle of them. with the listening area starting at 9' away. The ideal coverage area is defined as where all listeners are in the 90deg optimal radiation triangle presented by all three speakers concurrently. From the center, our listening area has a minimum width of 10.2 feet. Toeing in the right and left speakers, that entire area can be covered by their 90deg radiation, too, though the optimal listening area for anyone seated in a second or third row will also be only about 10 or 11 feet wide. (The way I set up my speakers, with dramatically "overtoed" mains, the optimal listening area actually starts just ~6' in front of the speakers, and covers the center's entire pattern at that distance. A less toed-in setup will give more of a seventh-row-center perspective at the listening position than the mid-hall perspective I prefer.) Outside that range, the system will sound equally good in the midrange, with simply attenuated treble the more one moves off axis and obviously the impact of varying bass modes.

Moreover, the early reflections will be of the same fundamental sonic character as the direct signal, except "warmer" due to the lack of treble from the original radiation and losses from reflections off of bookcases and the like. That will make the whole system sound more spacious and open.

The bottom line is, no other type of system will allow that wide a listening area except for an omnidirectional approach, and in that case you sacrifice the image specificity of direct sound. Still, an omni approach is consistent, and if that is one's sonic preference a perfectly reasonable way to go. The only approach that's indisputably wrong in terms of high fidelity is to employ speakers with poor power response. Especially in the midrange!


I've made absolutely no "subjective comments." I have only pointed out what is objectively required for maximally high-fidelity (that is to say "accurate") in room reproduction.


Why wait for Tymphany? Seas already does offer such a driver and has for at least 15 years, even though the tweeter isn't stout enough to provide truly constant directivity through the midrange. That is the stock version of the driver used by Gradient and I believe Vandersteen for their products. Their 5.25" version is better in that regard, and the fact that the woofer cone on that one is a pure midrange also is more a virtue than a vice.

Not quite as good as the Seas Millenium in reaching down low with low distortion, but still one of the top in the market in that respect. Overall, it has one of the lowest distortions of all DIY tweeters. I'm a little concerned that it's modified to reduce cost, but if it's truly a 6600, I'm impressed by SVS's offering.


Yes, if you stay inside the center lobe. As another poster mentioned, the off-axis responses are 45 degrees and 60 degrees. This is well outside the center lobe. A well designed MTM horizontal center works just fine +/- 20 degrees, which is a 40 degree listening window and quite suitable for most environments. I would say that your omission of the angle of measurement was deceiving, at best.

Yeah...the specs look great, but I wonder how that translates into real world performance. Is it really modified to reduced costs? I must of missed that.

DS, I agree with many of the points you make -- in larger venues.
This thread is (or should be) about typical cost effective residential setups, which generally can't fit vertical centers -- until you get to the perforated screen level, in which case you should be using three mains across the front -- and more specifically about the SVS MTS speakers. Restricting yourself to a $500-$600 retail price for a center that has to fit into existing furniture, your recommendations would be to use the Seas driver you mention, or use less expensive drivers and x-o components in a WTMW arrangement, trading off near axis SQ for a wider dispersion pattern -- and I humbly would rather spend the same money on better drivers and better x-o components.

Lets curb that rumor... it was speculation on my part. It's just that I have a hard time believing they can manage to put a $200 tweeter into an $900 speaker, and actually use it to it's full potential (with performance-matching midwoofers and crossover).

http://www.zaphaudio.com/tweetermishmash (make sure you follow the embedded link to "tidbits")

Thanks for the link. Spectral decay looks good down to 2k, so should be possible to cleanly blend with 6 1/2" woofers.


Thanks, Lindahl. I wasn't going to quote a specific number, but that's the same number I use: +/- 20 degrees, suitable for most residential applications.

[quote=Yes, if you stay inside the center lobe. As another poster mentioned, the off-axis responses are 45 degrees and 60 degrees. This is well outside the center lobe. A well designed MTM horizontal center works just fine +/- 20 degrees, which is a 40 degree listening window and quite suitable for most environments. I would say that your omission of the angle of measurement was deceiving, at best.[/QUOTE]

Here is a quote from Kevin Voecks, Director of Technology, Harman Specialty Group (Revel Loudspeakers, Mark Levinson, Lexicon):

"Other areas like off-axis response are very critical and we've learned that very far off-axis response like 60-75 degrees is very critical. Almost no one even measures it, let alone designs loudspeakers that are optimized at that sort of angle. But we've looked at real world situations and found that the all-important side-wall first reflection is a function of the speaker's output at that kind of angle in the vast majority of listening rooms. So it means that you're going to be hearing that kind of sound. You will hear it with a slight delay, and in many rooms without very much attenuation. So optimizing the response at that kind of extreme angle is very, very important. And then the power response, the reverberant field that we hear a little later in time is also important. So we literally design for all of those areas: the direct sound, the first reflection sound, and the reverberant field, because we know that all those three things are huge contributors to the timbre, to our perception of the speaker's timbre."

Sound inside the center lobe is NOT the only issue. Off-axis response is very important. And that goes without mentioning the MTM's wide open dispersion towards the ceiling and floor as mentioned earlier.

OK...got it. $200 retail.....it would not be anywhere near that to SVS with OEM pricing and quantities.

I would say it's much less important for a center speaker, which is generally far enough away from sidewalls in a typical environment to be a serious issue. Understandably, this is a problem if a wall is close enough to it, yes. As for anecdotal evidence, I've done measurements on a horizontal center before and after gobs of treatment have been applied to the sidewalls, and there was no appreciable difference in it's frequency response (which was relatively flat for an in-room response). I'll see if I can dig them up.


A WTMW doesn't improve on this, so I'm not sure why it was even mentioned.

Not sure which mention of the WTMW you're referring to. But a properly designed one, like the Revel Concerta for instance, will be much better off-axis than any MTM speaker out there. And off-axis response is important because you will be hearing a combination of direct and reflected sound, even from the center speaker.

I was referring to the MTM's wide open dispersion towards the ceiling and floor as a negative attribute for that design.

As I said, from testing, the off-axis anomalies from an MTM center don't have the same importance (in fact, no audible importance in a typical room), when considering reflected sound, as the off-axis response and reflected sound talked about in the article you quoted. When I have time this weekend, I'll try to dig up some graphs to illustrate my point.


Yes, but it's a negative attribute for anything but a vertically constrained speaker (which a WTMW isn't), so it's a strawman in the context of limitations of an MTM horizontal center. It shouldn't even be brought up in this discussion!

What the hell do you think I'm talking about? I don't know anything about larger venues and am not particularly interested in them. My interest is in "normal" residential audio.


Who said anything about needing a vertical center? That's funny. My HT center is only 9.5" high and meets all of the conditions described above.

And for the record a WMTW is manifestly superior to a toppled MTM. Here are the measurements for a competently designed one, from Revel.

And note that a competently-designed WMTW also doesn't have major issues in the vertical response, unlike the toppled MTM:



Illustrating why a specific design is fatally flawed by the design choices made in it certainly falls within the scope of discussing that design. And the SVS MTS speakers. Perhaps not more or less fatally flawed than many of the speakers out there. But if people are going to breathlessly hype a speaker that's not even out yet because it trades good fundamental design for being able to advertise the use of expensive tweeter and looks like something KEF did a decade ago but with inferior acoustic design, then they should expect that people who actually know a little something might speak up.


I get the distinct impression that most people here would be more than happy with Bose-like speakers that used expensive name brand parts, and a corner stack of Jello Fathom or Velodyne subs to shake the place. Not exactly a crowd of critical listeners here...

Good design is always going to beat expensive parts used stupidly. And a toppled MTM is a textbook example of "used stupidly."

Just because you can poorly design an MTM center, doesn't mean all of them are bad. Anecdotal measurements only work to support the other side of the argument - which I plan to show as soon as I get some free time at home.


Neither have major issues in vertical response. Only vertical MTMs and controlled-directivity speakers have major issues in vertical response, once outside the main listening angle. It's time you gave up on this strawman.


EDIT:

Here, look at the vertical off-axis response of the 1266-SE floorstander. As you can see, if you stay within a reasonable listening angle (+/- 15 degrees), there is no problem with the off-axis response of a well-designed MTM along it's longer axis. If you want to argue about off-axis responses interfering with the on-axis frequency response, due to the reflections off the side walls, you'll have to wait until I can do some measurements at home. I can assure you that the reflected off-axis frequency response does not appreciably change the on-axis frequency response for a typical positioning of a center speaker. The only appreciable differences are in impulse response and decay times, which aren't a real problem in a typical room at frequencies in which the mid-woofers interfere. If they are problems, then you have much bigger problems with your listening space than a horizontal MTM center (live in a small glass house, perhaps?).

No. As already pointed out you are just trading horizontal lobing for vertical lobing.
Vertical lobing is going to be more noticeable with the speaker above or below the set and much more likely set-up than sitting outside the 10' wide horizontal lobing free spot at 10'. Then you add the issue of another crossover and the phases changes of a 3 way.