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View Full Version : 340c v. ELT center



curtis
01-02-2004, 01:28 AM
My thoughts are different, and I think you should give both a try. I personally know Mad Dog as a friend, and rather get into a "I said, he said" issue, I think you should hear both. I will say that the ELT center is the best piece in the ELT system.

One of the strong points of Ascend speakers, and not just the 340, is vocal reproduction.

-curtis

Bob
01-05-2004, 01:47 AM
<blockquote id="quote"><font size="1" face="Arial, Verdana, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> the 340C by contrast sounded like the vocals were coming from inside the cabinet. not something that i like in my center channels. i attributed the differences to the respective speaker driver arrangements. the ascend uses a MTM (mid tweeter mid) driver arrangement which has been criticized for lobing effects when used in a horizontal position. this lobing effect primarily detracts from the clarity in the mids and highs, most of the frequencies used to reproduce voices. the ELT center uses a tweeter over mid with 2 woofers on either side of the tweeter and mid. this driver arrangement allows for superior clarity and focus in a center channel.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I did not know this kind of arrangement problem of 340c. But it is kind of sad to know. Any comment for this, anybody?

curtis
01-05-2004, 01:55 AM
I was there and did not detect that problem. There are many center channels that utilize the MTM configuration. AV123's Reference Center channel that sells for $950 uses the same design. Lobbing also has a lot to do with how the sound radiates from the driver, not just how the drivers are positioned.

We can banter back and forth between the boards as to the merits of each speaker, you should listen them yourself and decide.

If someone has experienced the lobbing effect...please chime in.

-curtis

Bob
01-05-2004, 02:06 AM
Curtis, thanks for quick response.
Would you mind if you explain what exactly the lobbing effect is?

curtis
01-05-2004, 02:31 AM
Lobbing, I believe, is caused by certain frequecies from the woofers reaching your ears at different times. It obviously happens the farther off center you are from the speaker. This can also be addressed with crossover design as well.

You might to talk to Ascend to see how they get around the problem.

-curtis

Quinn
01-05-2004, 05:42 AM
My 340 has never sounded like the vocals were coming from inside the cabinet.

I believe the vast majority of CC are a M-T-M design.

Bob
01-06-2004, 01:44 AM
I cannot say if my 340c is under the lobbing effect but I can say that it sounds like the vocals are coming from inside the cabinet. And I thought it is very natural for center channels. But i am not sure if it is due to the speaker or receiver.

curtis
01-06-2004, 02:33 AM
Bob,

How do you have it sitting on your TV? Is it at least flush with the face of the TV?

-curtis

Bob
01-06-2004, 06:54 AM
Yes, furthermore it is more than flush about 1 inch. I am using low end receiver, Yamaha rxv-530, and I suspect it is because of the receiver.

davef
01-06-2004, 11:36 AM
Just the other night I was watching SWAT with my wife and we both commented on just how natural the *full range* of Sam' Jackson’s voice was reproduced through our CMT-340c. I am most proud of this speaker :)

I was hoping to avoid a technical discussion regarding MTM designs and “lobing” but a few public negative postings from perhaps 1 or 2 non-Ascend customers are creating quite a stir. Business as usual I guess…

In as simple as I can explain terminology, “lobing” is used to describe an acoustic effect created by two identical sound waves reaching the listener’s ear at different times. If you are to the extreme right of the speaker, the right woofer’s sound waves will reach you before the left woofer. Imagine two identical sine waves drawn on top of one another but the second one is offset a bit on the horizontal axis. Instead of lying on top of one another, these waves will now intersect at certain points. At these intersection points, the two waves will either be somewhat in phase or somewhat out of phase. When the intersection point is in phase, the second wave will support the first causing an increase in amplitude. Conversely, when they are out of phase there will be a decrease in amplitude. This can have the audible acoustic effect of diminished clarity.

Fact # 1: Unless the loudspeaker is a single point source, ALL loudspeakers will exhibit lobing.

Fact #2: The MTM design is well proven in the audio industry; it is a design choice, NOT a design flaw.

Fact #3: All loudspeaker designs are a compromise; each specific design offers advantages combined with certain disadvantages over another design.

Regarding our CMT-340c:

Like all our loudspeakers, this speaker was designed to be extremely accurate. We specifically chose the woofer – tweeter – woofer configuration for several reasons that I will later address. First of all, the lobing effects of MTM configurations are only evidenced when listening off-axis, usually at extreme angles. Several design features have been incorporated to specifically minimize off-axis lobing

1. We used a high performance tweeter with a low resonance frequency. This allows for a lower crossover point which in turn allows more of the speaker’s critical midrange response to be reproduced by the tweeter. This increases the horizontal off-axis angle at which lobing first becomes evident.

2. The woofers use a steep 4th order slope in the crossover. This further reduces off-axis lobing while also increasing the off-axis listening angle by greatly reducing the directional high frequency energy reproduced by the woofers.

3. Notice how closely spaced the woofers are to each other? Spacing the woofers closer together further reduces off-axis lobing.

What are the results of these optimizations? Off-axis lobing only becomes evident by measurement at a horizontal angle of 20 degrees or greater. That is by measurement, not what is actually audible as our measurement equipment is far more sensitive then human hearing. To my experienced ear, off-axis lobing only begins to become audible at an angle of 25 degrees. So, what does that mean exactly? Quite simply, if you are 12’ back from the center channel, the accurate listening window for the speaker is approx 9’ wide. Off-axis lobing will not be audible unless you are sitting outside this listening window. Lobing effects with this speaker are simply not a factor unless you enjoy watching your TV and listening to your home theater system considerably off-center. And in this case, far greater acoustic problems will become evident (because you are most likely sitting directly across from your left or right speaker :) )

Why did we choose this specific design as a center? Our design goals are to build speakers that reproduce the source material as accurately as possible. Here are some advantages of the MTM design over a design with a woofer – midrange- tweeter atop midrange – woofer design. I will call this the M-TM-M design.

MTM design (when used horizontally) has vertical symmetry and wider vertical dispersion. M-TM-M design places a tweeter on top of a woofer which is obviously not vertically symmetrical. If you are below the speaker, the energy from the middle midrange woofer will reach your ear before the tweeter. If you are above the speaker, the tweeter energy will arrive sooner. Sound familiar? This is vertical lobing and its effects can be quite nasty if the speaker is sitting high on top of or below a TV.

The 2-way design of our 340 center uses a single crossover point. The 3-way design of an M-TM-M design must have 2 crossover points. The fewer the crossover points, the less phase problems and the better the driver integration. This equates to a more linear on and off-axis response, which closely resembles our acclaimed CBM-170s. Remember, a center MUST be tightly timbre matched to the left / right speakers. The frequency response, phase characteristics, and polar response between a 3-way speaker and a 2-way (even if they use the same drivers) will differ dramatically. No way around this.

Typical 3-way speakers are designed so that the midrange driver shares the same cabinet volume as the woofer. Big problems here…. As we all know, the inside of a speaker cabinet is subjected to tremendous pressure changes. When a small midrange woofer is sharing the same air space as a larger woofer (or worse, 2 woofers), the midrange driver will modulate with the pressure changes caused by the two bass woofers. We have all seen what happens in a dual woofer design; manually pushing one woofer inward will force the other outward etc. When the small midrange driver is trying to reproduce its signal, the larger woofers will actually cause unwanted compliance changes, thus producing high levels of intermodulation distortion. This is easily measurable and audible, regardless of where the listener is seated. It is for this very reason that in true “high end” loudspeakers, the midrange drivers in a 3-way design are almost always in their own dedicated cabinet section.

It is true that the M-TM-M design (if done properly) can have less off-axis horizontal lobing. This is simply due to the woofers of this design rolling off earlier and effectively offloading the midrange response to a single driver. In this case, I am assuming that the crossover point between the woofers and the middle midrange is lower and the slope is at least the same as that of the crossover point and slope between the woofers and the tweeter in the MTM design. Even still, the midrange crossover point must be quite a bit lower in the M-TM-M design because (due to the size of the middle midrange), the woofer spacing will be greater than the MTM design. All in all, we might be talking about only a few degrees difference between one design and another where lobing will become audible…

I would be happy to measure and discuss the lobing effects between our 340c and any M-TM-M center speaker provided one is sent to me :)

Please don’t assume the technical characteristics of one loudspeaker are “better” than another simply by a choice of design. Remember, I chose our design for a reason. I certainly would not assume my old 8-cylinder Mustang could even compare performance wise to one of the new highly tuned 4 cylinder pocket rockets simply because, technically speaking, with all things being equal, an 8 cylinder engine will have more horsepower than a 4 cylinder…… All things in comparison to our speakers are not equal…. Just look at the quality of our unique woofers and the tweeter we used in our 340c.

I am not surprised at how the most critical aspect of speaker design (the drivers used) is so seldom discussed by the self-proclaimed experts on the various online forums….

Thanks for your time!



Good Sound To You!

David Fabrikant
www.ascendacoustics.com

X52
01-06-2004, 11:54 AM
This is why I love this company. [;)]

JH

Bob
01-06-2004, 12:20 PM
I am so pleased to be an ascend customer.[:)]

Jonnyozero3
01-06-2004, 12:51 PM
Wow. I just learned a lot. Dave...I can't wait to give you my money...

(checks acount...not time yet...) DAMN!

Jon O.

ps: somebody send him one of *those speakers* from *that* place so he can measure! :)

azanon
01-11-2004, 09:48 PM
Dave,

First of all, excellent post. I think the speakers are wonderful, and that post helps explains why they are. I do have one comment for you though per a comment you made there as well as one you made in the "340c got a bad review": I think internet hype is you guys friends, not your enemy. As an internet company, I dont see how you guys can avoid the scrutany of the internet, even if its from audiophile wannabees. Taking an optimistic point of view, there's just too many (honest) people around that the truth, whatever that is, isnt gonna come out. I wasnt gonna spend ~1500 on speakers until i did a comprehensive online review of all the choices available to me. I did that one month ago, and from my analysis you guys came out on top for that dollar range. Sure many say you should demo speakers for yourself first, but i'm a busy man and have no problem trusting the concensuses of the masses. I like the odds of ~98 percent (or better) out of 100 ascend listeners loving their speakers. As it turned out, i love mine too.

I guess it is theoretically possible for a large number of people to attack an excellent company that makes superb and afforadle products. But lets get real: If you ask me, the only companies that have anything to fear from internet scrutany are those that make poor and/or overpriced products (*cough* **** *cough*). So I say embrase the internet - if for no other reason because you guys are winning: at lease you are from where i'm sitting.

davef
01-13-2004, 09:26 AM
Hi,

Just getting back from a succesfull CES.

Thanks so much for the nice comments in this important thread :)

Azanon- I am certainly not against unbiased Internet hype and I am ALL FOR intense product scrutiny. A fine example of this was sending our CBM-170 up to Canada for intense third party measurements in a "true" anechoic chamber. We had no idea we would end up winning a Year End Award due to this. I think we might be the only "net direct" loudspeaker manufacturer that continues to send our products to knowledgeable reviewers who have the technical background to take real world measurements. Not software simulated.

I will put our loudspeakers up against ANY out there in double blind listening tests and objective measurements.

What bothers me about Internet Hype are the hundreds or sometimes even thousands of people posting things like "best bang for the buck" or "best loudspeaker for the money ever" or simply, "my speaker is better than yours...".

Our line of loudspeakers will reproduce the source material more accurately than the majority of our competitors. This is what we believe the definition of a loudspeaker is.

Other manufacturers strive for their own "signature sound". Is one design "better" than another. It is ALL just a matter of opinion.

I heard a pair of loudspeakers at CES that literally blew me away. I loved them and for the quality they offered were surprisingly affordable. I won't give anything away but they were not net direct. I even preferred these over a $60,000 pair of loudspeakers I heard. However, I still can't say that one is "better" than another.. just different. If I even mentioned that I (as a consumer) were interested in hearing other peoples feedback on this speaker, I am convinced that all I would get would be, "Don't buy that, buy this, mine sound better"

The audio forums are a great tool for learning and resarching, but they have become so incredibly biased towards particular brands that people in the know simply can't stand reading the majority of the posts.

A good product certainly deserves hype, as does a very bad product. However, when the hype becomes so jaded that someone is frowned upon because they liked brand X better, this damages our entire industry.

I say bring on the hype, but let us all be open minded, RESPECT someone else's opinion, and, develop our own opinion's instead of falling into and being swallowed up by other people's opinion's.


Good Sound To You!

David Fabrikant
www.ascendacoustics.com

Quinn
01-13-2004, 11:52 AM
DaveF- My money is on these- http://www.adnm.com/cesclarity.htm

davef
01-13-2004, 12:51 PM
Nope... but I wish I had heard these!


Good Sound To You!

David Fabrikant
www.ascendacoustics.com

azanon
01-13-2004, 10:13 PM
Thanks for that follow-up Dave. I can't argue that the best way to go about evaluating speakers on a personal level is to listen to them for yourself and go with your preferences. And when doing so, its possible you could end preferring a set of speakers that is not one of the popular hyped-up brands at the time. With infinite time, money, and patience (ie: shipping heavy speakers back to a company), that's what i would have done.

I guess just due to limited time, i went with a mathematics/probability approach. Let me use an analogy: I have a new baby boy, and lets pretend he never got to drink a softdrink of any kind until he was eight. Then i could set a Coca-cola, Dr. Pepper, Sprite, and Orange Crush on the counter. My son could ask me, which one will taste best? What would my answer be? There is no correct answer, because it is a subjective matter of opinion... but that being said, i'd tell him you'll probably like the Coke Best, which would be a mathematically correct statement. Why? Cause more people prefer the flavor "cola" over all other softdrink flavors. Its a statistical fact, regardless of how much that might piss one off if Coke is not one's favorite.*

My second choice was Rockets in my personal decision. Wanna know one of the main reasons i didnt choose them? That catchy name of theirs. "Onix Rockets" Damn that sounds cool. Cool enough to win several hundred customers on phonetics alone. In fact, i cant decide which sounds cooler, **** or "Rockets". They seemed to have roughly the same spirited following (ok maybe a tad more, :-) ) that you guys have, but you guys dont have that, hit you in the chest name. So why are you guys so popular then? Was it the name? Ehh - its ok but its not "****". How bout the finish on the speaker? Nah, nothing fancy there though a very well built speaker. How bout the logo? nope. What the hell is it then? Was it a big price tag? Nope. The only thing i could come up with was that its the sound.

Dont get me wrong though. I put a lot of stock into those third-party reviews as well (ie: the Canadian one).

Bradley

* Admittingly, the chances of him liking either Dr. Pepper, Sprite, or Orange over just Coke "might" be greater, but you get my point.

davef
01-14-2004, 09:08 AM
Terrific point and very well explained!


Good Sound To You!

David Fabrikant
www.ascendacoustics.com

Ben_Wood
01-14-2004, 05:41 PM
I remember when "MTM" meant "Mary Tyler Moore"! [:D]

curtis
01-14-2004, 11:26 PM
LOL...

You know Ben, I bet there are some members young enough not to understand that one.

-curtis

Bighitter
01-14-2004, 11:48 PM
Technically I am young enough but thanks to the wonder that is Nick at Nite when I was a kid I know of her show.

mattepntr
01-15-2004, 02:45 AM
To quote the immortal Chuckles the Clown...

"A little song,
A little dance,
A little seltzer,
down your pants."

G'night, Chuckles.

Ben_Wood
01-15-2004, 09:42 PM
Bighitter, because of Nick@nite and TV Land, my kids (ages 9 and 11) have been exposed to some timeless classic T.V. My youngest one didn't really understand for a while that "The Beaver" is actually middle-aged now! [:D]

Larry.H
02-17-2004, 01:51 AM
and dont forget I Love Lucy, first time we heard are daughter laugh was when she was watching the candy factory episode