Ascend Acoustics CBM-170 Review

[Nicholas Mosher]

While I haven't listened to the 340m or 340c, I'm sure they sound excellent given the performance of the 170, and the fact that they share the same drivers.

I personally notice the difference when placing a speaker down below or up above a TV. I gave this issue a higher level of importance over other Home Theater factors (display options, room decor). While I haven't tested the 340c with 170s, I did notice a difference when I auditioned similar setups from Paradigm, B&W, and Thiel (4 Bookshelves w/an M-T-M or horizontally styled center). My personal preference was 5 identical monitors at equal height, and as Ben mentioned, is recommended for many sound formats such as DD, 5.1 DVD-A, and 5.1 SACD. I believe DTS and THX also recommend this speaker arrangement with the exception of the surrounds.

The best thing to do if you're interested is to try it out at a local hifi store, or order both a 170 and a 340 for the center, and choose which one you like best. Then you can either ship one back, or save it if you ever want to upgrade to 6.1 audio such as DTS-ES discreet.

One thing I didn't mention above is that when first getting into this I was nervous that 120W wouldn't be enough power for drawn-out action sequences. After auditioning other speakers with similar sensitivity ratings to the 170, I found that 100W was plenty. My 120W amplifier powers them with spades. In my room (18' x 10' once again) 85dB reference levels are acheived easily with 120W and no audible distortion, maybe some slight congestion in the upper range during complex action scenes compared with speakers at 10x the price (like the Thiels I love). This is when effects are peaking at SPLs that make my ears ring. At normal volumes they sound near-perfect.

Anyways, I don't think you can go wrong with the 170s, and I'm sure the 340s are also impressive.

[bikeman]

[QUOTE=Nicholas Mosher]While I haven't listened to the 340m or 340c, I'm sure they sound excellent given the performance of the 170, and the fact that they share the same drivers.

I personally notice the difference when placing a speaker down below or up above a TV. I gave this issue a higher level of importance over other Home Theater factors (display options, room decor). While I haven't tested the 340c with 170s, I did notice a difference when I auditioned similar setups from Paradigm, B&W, and Thiel (4 Bookshelves w/an M-T-M or horizontally styled center).


If one of the folks from Ascend dosen't answer this, I'll repost Dave F's detailed explanation of the 340C and why it's different from some of the other centers you've listened to and why it's a sonic match for the 170's. It was designed for the 170's, not the 340M's.

My personal preference was 5 identical monitors at equal height, and as Ben mentioned, is recommended for many sound formats such as DD, 5.1 DVD-A, and 5.1 SACD. I believe DTS and THX also recommend this speaker arrangement with the exception of the surrounds.

Nothing wrong with using identical speakers in identical setups but you're one of the few who has that option. The 340C gives us the same result without having to place the a speaker stand and speaker below the display. How it looks is really, really important to SWMBO.

David

[Nicholas Mosher]

I hear you on the Wife Acceptance Factor Dave. My father is in Mortal Kombat with my Step Mother over a big-screen TV. I like those shirts that say...

My wife said it was her or fishing... boy I'll miss her.

They should make one for Home Theater!

I haven't A/B'd the 340c vs 170 so I can't give an official comparison review, so anything I'm about to say should be taken with a grain of salt. I would have to say (just from what I've read here, and my experiences auditioning various center channel speakers), that the special crossover used in the 340c is a well engineered band-aid to combat the problems of off-axis response and diffraction. How well it works, I don't know, but I'd say to those that do have the option to go with five monitors (whether 340 Mains or 170s) that you should try both ways to see which you like best.

[bikeman]

"that the special crossover used in the 340c is a well engineered band-aid to combat the problems of off-axis response and diffraction."

This should bring Dave F. out of the woodwork. Good job, Nic.

David

[davef]

This is a great discussion and since Bikeman called me out, I thought I better respond

Nicholas made some great points and I would have to agree with most of them. If you are after the most seamless and timbre matched multi-channel soundstage possible --- and (I must stress this) you won't be placing your center channel on top of or below a TV and you do not require the lower profile typical of a center channel... ideally, 5 of the exact same speakers are the best way to go, provided they are all mounted and positioned at the same height and with the exact same method (all on stands for example).

That being said, there are also some advantages even in Nicholas' setup to using the 340 center. As most of you know, the center channel is the most critical speaker in the home theater system and our 340 offers improved dynamics, lower distortion, deeper bass and the ability to play really loud if need be. Factors that I feel are just as important as a seamless soundstage.

In Nicholas' setup, it really comes down to personal preference and what your performance goals are; enhanced dynamics and improved clarity vs. a truly seamless soundstage with perfect timbre matching. There is no right or wrong here...

Now.... if you do intend to place the center on top of or below a TV (subjecting the speaker to all sorts of nasty boundary effects), the obvious choice should be the 340 center.

that the special crossover used in the 340c is a well engineered band-aid to combat the problems of off-axis response and diffraction

Well I don't like to think of it as a band-aid (hey, it was hundreds and hundreds of hours of work) it is the only way to compensate for the boundary effects caused by placing a loudspeaker on top of or below a television. There simply is no other way to do it, other than physically placing the speaker in another location (which can hurt the localization of dialogue, so dialogue sounds like it is coming from the TV and not somewhere else).

In this regard, I will say that our “band-aid” works quite well

[davef]

Hey Nicholas,

BTW, I LOVE the look of the CBM-170s on those SP-30 speaker stands!

[Nicholas Mosher]

Definetly not trying to knock any other speakers Dave has designed. By what I've experienced with the 170s, I'm sure the other offerings are just as great for their intended application.

I am curious about what you said about the 340 having greater clarity and improved dynamics with less distortion. Would I be right in guessing this is only when playing at high SPLs while pushing the lower end frequencies? I noticed the 340s have a slightly higher sensitivity in the specifications listing, while the 170 frequency response graph shows a flatter plot. Am I seeing two different tweeters between the 170 and 340 as well?

I was also hoping to get an opinion from you about the HSU subs you deal. How do they sound with 2ch music in your experience. I'm also curious about what equipment you use for your own personal HT & 2ch listening.

Thanks,
~Nick

EDIT: Thanks for the comment on the SP-30 stands. I thought they matched the CBM-170s quite nicely. They can't be adjusted like the OMNIMOUNT stands you deal, but you can fill them with sand or lead-shot which is cool. Apparently this is supposed to isolate the speaker in space. I'm going to experiment to see if there is any truth behind it.

[DavidD]

Now.... if you do intend to place the center on top of or below a TV (subjecting the speaker to all sorts of nasty boundary effects), the obvious choice should be the 340 center.

Well I don't like to think of it as a band-aid (hey, it was hundreds and hundreds of hours of work) it is the only way to compensate for the boundary effects caused by placing a loudspeaker on top of or below a television. There simply is no other way to do it, other than physically placing the speaker in another location (which can hurt the localization of dialogue, so dialogue sounds like it is coming from the TV and not somewhere else).

In this regard, I will say that our “band-aid” works quite well

So...if I plan to put the center on a stand in front of the TV, then you would not recommend the 340 center? Would you recommend getting a 340M or 170 in that case?