Ascend CBM-170SE2 Speaker Review

[Billy Budapest]

Very good point. That term usually refers to a sealed box design using principles usually attributed to the work done by Acoustic Research in the 1950s.

That is my understanding and I have never encountered the term being used to signify something else.

 

[Timcognito]

WOW at this price and size this will be HT speakers of dreams when paired with sub and center channel and double down on your 2.1 music, as well, for an all in one set it and forget it system.

 

[eddantes]

Great achievement for such an accessible price!

 

[TurtlePaul]

What could be the benefit of Ascend Sierra 1V2 vs these? $998 Vs $498

1. Bass extension. 45 hz vs 54 hz -6dB extension is a huge difference. Not even just electronic music and hip hop. Rock and roll drums will sound thin on these, the Sierra-1 v2 will be passable, and the Sierra LX will be fine for rock or pop. These seems optimal for the sattelites in 2.1/5.1/7.1 systems while the Sierra line up is passible without a sub.

2. Power handling. The drivers on the Sierra lineup have larger motors, higher power voice coils, bigger baskets, etc. The good think is that the CBM-170 are sensitive so they only need a few watts. You can see some rise in wide band distortion in the 96 dB distortion test despite this being <20 watts.

3. Fit and finish. I had the original CBM-170 in college (20+ years ago). They fit right in with the dorm furniture. The new speakers have a better finish than those originals but are still vinyl wrapped MDF. The Sierra lineup is solid laminated bamboo with a variety of varnishes and paints. The finish is furniture grade. The Sierra lineup is also ~50% bigger and 5 lbs per speaker heavier. The Seas and Raal drivers used in the sierra lineup look obviously higher quality when you see them in person vs. the soft dome tweeter and polygel (thin plastic) CBM-170 drivers.

 

[tw 2022]

WOW at this price and size this will be HT speakers of dreams when paired with sub and center channel and double down on your 2.1 music, as well, for an all in one set it and forget it system.

agreed , this isn't necessarily a "starter" speaker.. to me it's a legit monitor for those that value SQ over looks ...perfect for dual use systems in a small room , and you aren't giving away performance to get "good looks"....

 

[Multicore]

Love this kind of speaker, well made/designed at a reasonable price, with objective data.

And nice people too. Attentive. Ime.

 

[Power Pop 23]

Thank you to @AscendDF, for creating this performant option.

Thank you to @amirm for devoting the time to independently confirm the performance.

 

[daniboun]

There is a port so that does not appear to be a correct statement.

A question slightly off-topic: are the ASCILAB F6BS acoustic suspension speakers ?

 

[Matt_Holland]

A question slightly off-topic: are the ASCILAB F6BS acoustic suspension speakers ?

Hard to know without analysis of the driver/box combination, but I remember there being a qualitative definition in the Loudspeaker Design Cookbook, so used ChatGPT to find it:


According to the classic reference The Loudspeaker Design Cookbook by Vance Dickason, an acoustic suspension loudspeaker is defined by the relationship between the driver’s suspension and the air trapped inside the enclosure.


In essence:


An acoustic suspension loudspeaker is a sealed-box system in which the compliance (springiness) of the enclosed air is the dominant restoring force acting on the woofer cone, rather than the mechanical compliance of the driver’s own suspension.


The key characteristics described in the book are:

• The enclosure is completely sealed (no vent or passive radiator).
• The woofer is designed with a very compliant (soft) mechanical suspension.
• The air trapped inside the cabinet acts as an air spring, controlling cone movement.
• The compliance of the enclosed air (Cab) is lower than (stiffer than) the driver’s suspension compliance (Cms), so the air spring dominates the system.
• This results in:
  
  • excellent low-frequency transient response,
  • low distortion due to good cone control,
  • a smooth 12 dB/octave low-frequency roll-off,
  • lower efficiency than comparable vented systems,
  • the ability to achieve relatively deep bass from a compact enclosure, at the expense of amplifier power.

An important distinction made in the Loudspeaker Design Cookbook is that not every sealed loudspeaker is an acoustic suspension design. A sealed enclosure only qualifies as acoustic suspension if the air spring is the primary restoring force. If the driver’s mechanical suspension is stiffer than the enclosed air, then the system is simply a sealed (closed-box) loudspeaker, not an acoustic suspension system.


This distinction is often overlooked in marketing literature, where “sealed” and “acoustic suspension” are sometimes used interchangeably, even though Dickason (following the original work of Edgar Villchur) treats them as technically different concepts.

 

[phoenixdogfan]

Just serves to illustrate that great design doesn't cost any more than bad design. And we obviously have the former here. These are absolutely amazing little speakers for $468 pr. Add in the Wiim unit and you have something perfect for a dorm room or a small apartment or bedroom. Dave Fabricant deserves all the love this forum can give him. He's really one of the unsung heroes in audio today offering well engineered, high quality, high value speakers, and doing it in the American market. His speakers definitely need to be on the short list for anyone looking to upgrade in just about any price bracket. He's just making stuff that's every bit that good. And these speakers break new ground for value at their price point. Great job, Dave.

Thank you for the always excellent review, Amir. The Chat GPT add in was very interesting as well.

 

[capslock]

These look just like a throwback to the 90s. Quite decent radiation pattern for no waveguide. And while the midbass looks simple, both it and the tweeter show surprisingly low distortion.

 

[JimWeir]

This is a review, listening tests and detailed measurements of the Ascend Acoustics CBM-170SE2. It was sent to me by the company and costs USD $248 each. $468 a pair.
View attachment 549277
There is a grill which I removed, making the speaker look utilitarian. Pick it up though and you realize it weighs more than you expect.

Love the mention of NFS Optimized text on the label:
View attachment 549278

Ascend CBM-170SE2 Speaker Measurement
As noted, I stripped the speaker off its grill and measured it with Klippel NFS using the tweeter center as the reference:
View attachment 549279

As noted, the general on-axis response is flat as we like. There are however some variations including a resonance around 900 to 1000 Hz and some slight shortfalls in treble region. The listening window though (dashed green) is smooth. Early window reflections sum well, indicating optimization in this regard:
View attachment 549280

All of this sums to a surprisingly good predicted in room response:
View attachment 549281

I know this is a major focus area for Dave (the designer).

Near-field response shows some of the unevennes of the tweeter:
View attachment 549282

I expected to have to baby the speaker during my power sweep but that was not so as it easily played even the 96 dBSPL signal without complaining:
View attachment 549283

View attachment 549284

Notice how much lower the distortion is at 86 dBSPL across the full frequency range! It wasn't until I got to 101 dBSPL that I heard some distortion at the start of the sweep:
View attachment 549285

There is no waveguide so we have natural beaming from the tweeter:
View attachment 549286
The benefit is wider dispersion at lower treble.
View attachment 549287

Vertical response is as we expect from 2-way speaker so best to stay at tweeter axis:
View attachment 549288

Impedance is about average around 3.5 ohm:
View attachment 549289

We have the usual resonances:
View attachment 549290

But clean step response:
View attachment 549291

Ascend CBM-170SE2 Speaker Listening Tests
As Dr. Toole is fond of saying, sometimes graphs bother the eyes more than the ears. Such is the case here if you look at the on-axis response. I was fully ready to have to add some small touches with EQ but none was needed whatsoever. The speaker played clean and loud with a level of fidelity that belied its looks and certainly its price. Indeed, the price has nothing to do with it. My reference tracks, one by one, impressed with no excuses needed to be made. Closing my eyes, I perceived a very large spatial image that helped in that regard. I am talking about a bubble that was 6 feet or more around and above the speaker! With a pair, the CBM-170SE2 will fill a large stage with delightful tonality and accuracy.

My sub-bass heavy track didn't bother the speaker one bit as it simply rolled it off instead of playing and getting distorted.

Conclusions
For less than $500 you get a speaker built in US that brings tears to your eyes as far as fidelity and enjoyment. This is what we get when we put the right tool, Klippel NFS, in the hands of the a skilled designer. "Measure it and will get better" and better it did. The only compromise is not playing very low which you wouldn't expect it to. Power handling is excellent as a result. Nothing like going into a review and expecting one thing, and getting handed something far better. Ascend breaks new ground here with this level of performance for so little money.

The Ascend Acoustics CBM-170SE2 is an easy strong recommendation from me.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

I was teaching a course on sound measurement and analysis representing Bruel & Kjaer for the local AES (Agricultural Engineering Society) meeting at John Deere HQ back in 1984. For my effort ai received a plaque with scales and a ruler on it that stated “Test engineers axiom: To Measure is to Improve”.
Definitely applies here.

 

[hutt132]

I had the original version of this speaker for many years and it sounded great. If this new version improves upon the already great sound, it should be a home run! Plus the new cabinet with a flat top and bottom is much more sleek and modern than the old design that had a rounded top and bottom.

 

[Matt_Holland]

I was teaching a course on sound measurement and analysis representing Bruel & Kjaer for the local AES (Agricultural Engineering Society) meeting at John Deere HQ back in 1984. For my effort ai received a plaque with scales and a ruler on it that stated “Test engineers axiom: To Measure is to Improve”.
Definitely applies here.

I see what you did there

 

[AscendDF]

Why does it say acoustic suspension speaker after NFS Optimized?

LOL - ooops... And just when I thought this was one of the easier product releases

We had our label company (here in the US) use the same label as our HTM-200SE2 with some changes, I'm not good at this stuff so typically I just send them the changes to the text. Looks like the change from using Acoustic Suspension to Bass Reflex did not get implemented.

Honestly not sure how this got past not only me, but my small crew here as well. 4K new labels just ordered!

Thanks for pointing that out, I wonder how long it would have before I noticed (getting older is NOT fun)...

 

[AscendDF]

Ah, Dave must have just changed it. I will update later.

Hi Amir,

We haven't made any changes. I believe you pulled pricing and specs from the "single" CBM-170SE2 page here:

CBM-170SE2 SINGLE SPEAKER

The Rebirth Of A Legend New Klippel NFS optimized version! The new CBM-170SE2 is a complete reinvention of our legendary speaker. Using today’s most advanced R&D tools, including our Klippel NFS, we improved every performance aspect while staying true to the original purpose: exceptional...

www.ascendacoustics.com

Rather than the pair page here:

CBM-170SE2 BOOKSHELF MONITOR PAIR

The Rebirth Of A Legend New Klippel NFS optimized version! The new CBM-170SE2 is a complete reinvention of our legendary speaker. Using today’s most advanced R&D tools, including our Klippel NFS, we improved every performance aspect while staying true to the original purpose: exceptional...

www.ascendacoustics.com

Thank you for the thorough and detailed review. Very happy you enjoyed listening to the speaker! That spaciousness you mentioned was a primary goal for this design, and was missing from the previous version.

 

[yofi]

Great performer.

This line has been around a long time. I remember seeing recommendations for them 15+ years ago. Glad to see them in good standing, and continuing to get better!

 

[AscendDF]

Great performer.

This line has been around a long time. I remember seeing recommendations for them 15+ years ago. Glad to see them in good standing, and continuing to get better!

Just shy of 30-years for our CBM-170.

 

[Chrispy]

What could be the benefit of Ascend Sierra 1V2 vs these? $998 Vs $498

Can only provide my own experience. I bought a set of v.1, with center already converted to NrT tweeter option, then later converted L/R as well myself. Have 170SEs (as well as 200SEs). The Sierra is a superior speaker and it's fairly obvious IMO.

ps the cabinets are quite different, and that I think is significant.

 

[dfuller]

Excellent performance for the price.

Anybody know what the woofer is? It looks like a SEAS custom design of some sort...