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Ascend CBM-170 SE Speaker Review

Stump909

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I've owned the 170s (gave them to my parents), the BS22's (sold to a friend), and JBL 305's (current nearfield). I don't know how it happened, but it's like the speakers reviews are coming straight from my collection. The 305's are obviously a personal favorite (minus the hiss I can't seem to remove), but I'm blown away at the thought of the 170s being 'bright'. I like neutral speakers and these fit the bill nicely. Even looking at the chart, the mid-range/treble only seems to fluctuate 1-3db higher, but overall the signature is still rather flat. When I think 'bright' I think the barf-worthy B&W 'house curve' or any modern Klipsch. Multiple comments of a 'shave', but ear fatigue was never something I experienced, nor can I imagine the results demonstrate that. Plus, let's not kid ourselves, they can be driven remarkably loud without any painful distortion (compared to hte BS22's). It seems the most vocal critics seem to have strong opinions on every Ascend product. This isn't Schitt Nonsense 2.0, plus they're reasonably priced. I would argue a fair valuation over the Pioneers too.
 

wwenze

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A shelf filter would make the frequency response pretty flat.

So there's some salvation for current owners.
 

JustIntonation

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It is a classic formula for a 2-way speaker. Sadly, it lacks a waveguide to better integrated the tweeter and woofer at crossover point.

The problem of a small tweeter and larger woofer without directivity control (e.g. waveguide) is seen above but magnified more when we look at directivity index:

View attachment 52611

The dashed blue line is difference between what you hear directly from the speaker and important (loudest) reflections around the room. Ideally these two match each other, sans a gradual reduction in high frequencies which makes the graph point up. Here, the blue line deviates a lot from the straight line meaning the off-axis response is colored relative to direct sound.

The integration of the woofer and tweeter at the crossover point is fairly good as far as directivity goes (of the drivers). The problems you're seeing have a different cause. And a large waveguide (and large is needed to have a substantial effect at the crossover point) would increase the center to center distance of the tweeter and woofer which would mean a worse vertical off-axis response unless crossed much lower still.
If you look at the horizontal off-axis response you'll see there isn't that much of a mis-match in directivity from the woofer and tweeter around the crossover, the mismatch seen here in the DI plots is because of the vertical crossover cancellation (a waveguide won't help here but instead would make it worse by increased CTC distance). And the decreased directivity we see a bit higher up in the tweeter is caused by baffle edge diffraction (here a waveguide would help, even a smaller one, by making the treble more directional and giving less edge diffraction, though a better solution would be a bigger roundover on the enclosure edges).
 

AdamS

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The cbm-170's were one of the first 'real' speakers I bought about 12-13 years ago. I used them in a 2 channel set up for a little while and then in a home theater room for a few years. They were decent.

The one thing they excelled at I thought was imaging and having a fairly large soundstage. How is this measured or even listened to with only 1 speaker being tested?
 

richard12511

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The cbm-170's were one of the first 'real' speakers I bought about 12-13 years ago. I used them in a 2 channel set up for a little while and then in a home theater room for a few years. They were decent.

The one thing they excelled at I thought was imaging and having a fairly large soundstage. How is this measured or even listened to with only 1 speaker being tested?

My guess is that it probably shows up best in the directivity measurements. My experience is that wide directivity will throw a larger soundstage with a wider sweet spot at the expense of sweet spot clarity. Educated guess on my part, though, as I really don't know.
 

maty

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They have less resonances than the more expensive Ascend Sierra-2 Reference Ribbon.

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laudio

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So where does one find the "formula" for the preference score?
 

617

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The cbm-170's were one of the first 'real' speakers I bought about 12-13 years ago. I used them in a 2 channel set up for a little while and then in a home theater room for a few years. They were decent.

The one thing they excelled at I thought was imaging and having a fairly large soundstage. How is this measured or even listened to with only 1 speaker being tested?

You know what also can't be discerned by listening to a single speaker? Bass response and tonal balance. Bass frequencies tend to reinforce each other more than mids and treble.

As far as what to look for in the measurements which signals good imagining - smooth off axis response is probably the most important thing. Wide or narrow dispersion can both work although wide is more room dependent, but preferable to many ears.
 

raistlin65

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That is what I did. Bass notes would reverberate strongly in the cabinet. So I tested the same on the Pioneer and was just as much. Not scientific but I expected the enclosure to be more stout.

Well, putting aside the imprecise nature of the hand as a measuring tool and the potential for expectation bias, they have a different bass response. A Bose cube would likely have little or no bass resonance using the same measuring method simply because it has no bass. To be more accurate it would seem you'd have to SPL match the speakers for bass frequencies.
 

bigjacko

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You know what also can't be discerned by listening to a single speaker? Bass response and tonal balance. Bass frequencies tend to reinforce each other more than mids and treble.

As far as what to look for in the measurements which signals good imagining - smooth off axis response is probably the most important thing. Wide or narrow dispersion can both work although wide is more room dependent, but preferable to many ears.
Why does the bass frequencies reinforce each other? Does it show on measurement?
 
OP
amirm

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Well, putting aside the imprecise nature of the hand as a measuring tool and the potential for expectation bias, they have a different bass response. A Bose cube would likely have little or no bass resonance using the same measuring method simply because it has no bass. To be more accurate it would seem you'd have to SPL match the speakers for bass frequencies.
No I don't. A speaker enclosure should be made rigid with respect to bass it produces. If it doesn't, and I happen to check for it, I report on it. These are two differently priced speakers. By that logic maybe I should shave half the enclosure from the Ascend to make the test valid....
 

Prana Ferox

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Amir, do you know why those resonances don't seem to show on the impedance plot? I see dips on the phase but any variation on the magnitude is hard to spot (other than maybe the 400hz one.)
 

jhaider

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Seems okay for the price, lots of good stuff now in this range but nearly all of it is made in China. Nothing against China but having a USA made product at this price point that performs alright is pretty legit.
There is no chance I am buying these but maybe some folks will appreciate the sound signature, some folks like bright.

The disappointment is, a waveguide would not add much to the cost, yet could transform the performance from its current "meh, whatever" to "giant killer." I felt the same way about the Monitor Audio Silver 1, which is to be sure a better speaker than this one in every aspect - considerably flatter on axis performance, finer materials, better fit and finish - but more expensive.

Princeton's 3D3A lab also measured this Ascend, in their anechoic chamber.
https://www.princeton.edu/3D3A/Directivity/Ascend Acoustics CBM-170 SE/index_DI.html

I'm not good at eyeballing different scales, but on first impression the one Princeton tested was a better performing speaker. I wonder if sample variation in drivers or crossover parts is at issue.
 

laudio

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aarons915

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The disappointment is, a waveguide would not add much to the cost, yet could transform the performance from its current "meh, whatever" to "giant killer." I felt the same way about the Monitor Audio Silver 1, which is to be sure a better speaker than this one in every aspect - considerably flatter on axis performance, finer materials, better fit and finish - but more expensive.

Princeton's 3D3A lab also measured this Ascend, in their anechoic chamber.
https://www.princeton.edu/3D3A/Directivity/Ascend Acoustics CBM-170 SE/index_DI.html

I'm not good at eyeballing different scales, but on first impression the one Princeton tested was a better performing speaker. I wonder if sample variation in drivers or crossover parts is at issue.

The princeton graphs only show 500Hz and up, so from that range they do appear neutral but you can still see the off-axis is too strong. Some people like that sound signature though and for home theater I could see people liking this speaker quite a bit. It also has very low distortion so it should be able to play loud cleanly, another plus for home theater.
 

ROOSKIE

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The disappointment is, a waveguide would not add much to the cost, yet could transform the performance from its current "meh, whatever" to "giant killer." I felt the same way about the Monitor Audio Silver 1, which is to be sure a better speaker than this one in every aspect - considerably flatter on axis performance, finer materials, better fit and finish - but more expensive.

Princeton's 3D3A lab also measured this Ascend, in their anechoic chamber.
https://www.princeton.edu/3D3A/Directivity/Ascend Acoustics CBM-170 SE/index_DI.html

I'm not good at eyeballing different scales, but on first impression the one Princeton tested was a better performing speaker. I wonder if sample variation in drivers or crossover parts is at issue.

Yah, I mentioned earlier maybe Ascend will become inspired to update. A quality waveguide was more rare back in 2006, now yes indeed the engineering in speakers is beyond another level in this price point. Hopefully they will throw down. Doesn't really matter though as there are numerous speakers to chose from in this price range and certainly we don't actually need more. I'd bet most of them have some issues as well.
I'd love to see how the ELAC budget gear stacks and as well the Q acoustics stuff. Another $300 retail or less speaker is the Emotiva B1+.
 

AdamS

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I agree that Ascend needs to update or revise their legacy speakers. I'm also surprised they haven't updated their website. I know he was talking about it being almost ready at least two years ago. I wonder what happened...
 
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