Ascend Acoustics Sierra-1 Bookshelf Speaker Review

[gene]

Is the shootout Tom mentioned involves blind test? In that case, it would be really interesting to see whether the testers can identify the recessed midrange of Ascend Vs the midrange of s520. Same thing with the Bass accuracy. Tom loves s520 way too much :-) At least he admitted that the comparison was not blind.
User is getting good reviews everywhere, I'm going to audition it at a dealer in next few days.

We didn't directly compare the Ushers with the Ascends. The Ascends are in a different class all together. We put speakers of similar pricing up against each other and heard quite a dramatic increase in fidelity from the $400/pr to $800/pr price class as expected.

For now lets keep the this thread on topic and start a face off review thread once that review is posted. thanks.

[billnchristy]

These are very pretty speakers.

I am seriously contemplating building a set of bookshelfs with that tweeter and maybe a 7" hi-vi.

[silversurfer]

These are very pretty speakers.

I am seriously contemplating building a set of bookshelfs with that tweeter and maybe a 7" hi-vi.

Will you do your own crossover too? That seems to be a pretty exclusive piece to the Sierra. The tweeter is supposedly customized for Ascend. I have seen a similar tweeter on Totem's wall mount speaker.

[PatrickBateman]

These are very pretty speakers.

I am seriously contemplating building a set of bookshelfs with that tweeter and maybe a 7" hi-vi.

I am pretty sure the tweeter is custom made for Ascend.

[Matt34]

I am pretty sure the tweeter is custom made for Ascend.

Text taken from AcsendAcoustic's owner David F description of the tweeter used in the Sierra 1.

In order to realize our goal of reducing the negative acoustic effects caused by each loudspeaker component, the Sierra would require a special tweeter. In addition to my typical requirements (linear on- and off-axis response and excellent extension), I demanded an exceptionally clean spectral decay combined with very low distortion. Of course, our good friends at SEAS of Norway were once again up to the task.

SEAS engineers recommended a new tweeter currently under development that I could customize to suit Ascend’s needs. Of course, this new tweeter took a bit longer than expected, but the first samples finally arrived and the results were very impressive. This new tweeter has a few unique features. It contains an integrated slightly elliptical wave guide made of flexible and absorbent elastomer. The subtle shaping helps control the off-axis response and aids in the reduction of diffraction, while the elastomer material helps absorb stray high-frequency wavelengths. The wave guide insert also has the added benefit of covering the magnet assembly screws, thus eliminating the pesky reflections these cause.

The tweeter also contains an extremely wide integrated surround (the part of the tweeter that attaches the dome to the faceplate). This serves to better dampen the dome, thus reducing various resonances and break-up modes.

We added our own customizations to this already superb tweeter to further improve performance.




The final result is a tweeter with an extremely impressive spectral decay. Both harmonic and IM distortion are extremely low and the frequency response is smooth and linear both on- and off-axis. This tweeter is incredibly natural sounding, with a clear and detailed character that is crisp without ever being fatiguing. It literally oozes that magical “airy” sound that is so elusive yet critical to a high-end loudspeaker.

Tweeter Features:

* Fully manufactured by SEAS of Norway
* 26mm high-definition pre-coated fabric dome
* Fully integrated slightly elliptical wave guide made from elastomer to reduce diffraction and control off-axis response
* Integrated wide surround for reducing resonance and break-up modes
* Low viscosity magnetic fluid for improved power handling and damping
* Pole piece damping chamber to absorb back-wave reflections and lower the resonance frequency
* Exceptionally clean spectral decay and low distortion for greater detail and improved accuracy

[WmAx]

Will you do your own crossover too? That seems to be a pretty exclusive piece to the Sierra. The tweeter is supposedly customized for Ascend. I have seen a similar tweeter on Totem's wall mount speaker.

As for good tweeters with typical monopole off axis response, very flat response, superb CSD and very low distortion, get a BG NEO 3 PDR. In addition to all of these traits you seem to want, it is an almost perfect resistive load (it's a planar), and can be used down to 2000Hz with appropriate crossover, making it extremely easy to integrate with a wide selection of mid-bass drivers.

The only notable thing about that tweeter, compared to what you can typically get DIY, is the waveguide. A waveguide (used on pro monitors for many years now) removes the edge diffraction disturbances that occur when the tweeter's sound pressure waves meet a sudden pressure change at the cabinet edges. The waveguide focuses the energy to be distributed more on axis, to remove the stray off axis energy. Of course, this further limited off axis response may not be desired, depending on the objective/end use of the speaker. But that's another topic. You can achieve the same diffraction reducing effect, with wider dispersion(a desirable thing in normal circumstances), by using very large radius on the cabinet edges (2"-3" for example). However, this can often lead to large increases in cabinet production cost, and as such, is a fairly rare feature in low and moderate cost production speakers. You can also make a waveguide if you have a lathe, and copy the profile of a known working unit. Or you can buy some plastic shallow horn waveguides, which are appropriate, if you shave the back off and mount the tweeter to the back at the appropriate depth. Zaph Audio DIY blog site has such an example thoroughly documented along with part numbers and sources. [Note: I do not endrose the Zaph site, I only refer to it in the specific citation of the DIY waveguide]

The Seas tweeter used by Ascend may be a nice integrated package. But I don't believe it's available to DIYers yet, and I am not sure of the cost. Will it be cost effective for DIY, as compared to the alternate methods to achieve the same effect it offers?

Another issue here is the cabinet. Due to the inherent increased stiffness of the bamboo, it would be substantially less resonant than a MDF cabinet of equal construction dimensions/bracing. While still not likely to be non-resonant, it would likely be a large improvement. This needs to be considered in the DIY cabinets. Typical MDF box construction methods/bracing, IMO, is worthless, for a supposed high-fidelity loudspeaker. The reviewer also commented that the speaker used what looks like fiberglass board cut up and placed in bags in the speaker. Could this be rigid fiberglass board? Like OC705 or equivalent? If so, it would be rare that a speaker manufacture bothers to use extremely high quality acoustic damping material. Normally, a low density fiberglass, low quality thin foam, or low density Dacron/poly fill is used. Usually sub-optimal. This should also be considered in the DIY design.

The Sierra, according to the manufacturer, uses a very low distortion mid-bass with long linear excursion/incursion. The surround of the mid-bass certainly appears to be unusually capable, though this is only superficial evidence. But let's assume this speaker really does have the non-linear distortion vs. excursion performance of say for example, a premium Seas Excel driver.

Overall, it would appear the Sierra is one hell of a well engineered speaker for it's retail price class.

-Chris

[billnchristy]

Here is the link for the tweet:

http://www.madisound.com/catalog/pro...oducts_id=1591

As for the X-over I was thinking about letting madisound design it with LEAP.

[silversurfer]

Here is the link for the tweet:

http://www.madisound.com/catalog/pro...oducts_id=1591

As for the X-over I was thinking about letting madisound design it with LEAP.

Yeah, externally it looks the same, but my understanding is that there are modifications internally. According to a post on the AVS forum, the one you linked to is not chambered(also the Seas site does not list it as chambered), but the one Ascend uses is. My guess Ascend combined some aspects to get a custom version of this tweeter.

To my knowledge, I don't think LEAP can create a variable slope crossover with the phase aspects of the Ascend crossover.

What other speakers have you built and why do you want to build a Sierra clone?

[Tex-amp]

Here is the link for the tweet:

http://www.madisound.com/catalog/pro...oducts_id=1591

As for the X-over I was thinking about letting madisound design it with LEAP.

Silversurfer is correct the tweeter in your link isn't a chambered tweeter and the Ascend version in the Sierra is.

[billnchristy]

Im sorry dude, but there is no voodoo in this: