Elac BS U5 Slim 3-way Coaxial Speaker Review

[Dennis Murphy]

Wow, it is uncanny how close it is to mine:

Well, that pretty much makes three of us, although my measurement is full of room modes below 300 Hz, and I can't get as much resolution in the 2 kHz region with my setup. I didn't take any distortion measurements. That big hump centered at 1800 Hz blurred upper midrange, lower treble detail and ruined the speaker for me. I think this is a text book example of a designer overestimating the importance of smooth far-off axis response and underestimating the much more important early-arrival response. In my experience, this often occurs in wave guide and coaxial designs. AJ has proven that he can get it right in some of his designs, mostly the Uber Expensive ones, but it didn't work this time (or in the budget Pioneer line).

 

[pierre]

Score: 5.0

 

[daftcombo]

Very interesting where we learn that distortion measurement does matter.
So, a distortion peak ar 270 Hz elevates response at 540Hz, 810Hz, etc.
Wouldn't it be intesresting to tame thoses frequencies as well or instead?

 

[q3cpma]

For a second time we see that the magic of coaxial drivers tends to be more for the eye than the ear.

I don't see how you come to this sweeping statement. I'd say that there's simply a vast difference in R&D between coaxial as a gimmick and as a feature, as Genelec or KEF showed us.
Anyway, ELAC proved that it doesn't belong to the second kind and should content itself with making good/better traditional speakers.

 

[edechamps]

I have added the Elac Uni-Fi Slim BS U5 to Loudspeaker Explorer where it can be compared to other speakers.

Good consistency within the listening window:

And I'll take the opportunity to mention that Olive Preference Rating calculation is now available in Loudspeaker Explorer:

 

[MZKM]

Preference Rating
SCORE: 5.0
SCORE w/ sub: 7.0

Sensitivity: 84.7dB
FR: +/-4.6dB 46Hz-20kHz ; +/-4.3dB 80Hz-20kHz

All graphs/data

 

[MZKM]

The horizontal performance becomes much better at 30°, so I would suggest no toe-in.

If this is the same performance as the UB5 which is 1/2 the price, this is a rip off and I have no clue why ELAC sells this for so much more (EDIT: I see others mentioning this is painted while the UB5 is a vinyl wrap). They even state it’s the same drivers and crossover components, they don’t even have a manual for the Slim line, it links to the regular models.

 

[tecnogadget]

I don't see how you come to this sweeping statement. I'd say that there's simply a vast difference in R&D between coaxial as a gimmick and as a feature, as Genelec or KEF showed us.
Anyway, ELAC proved that it doesn't belong to the second kind and should content itself with making good/better traditional speakers.

Exactly, this is a budget product, considering that the original Unifi UB5 was released at $500 msrp as an affordable coaxial design for those interested in LS50 and R300 who didn’t want to spend that much.
At the end you get what you paid, there is a limit in optimization and cutting corners.
Just looking to the exploded driver’s pictures shows that UniQ and this UniFi are not in same engineering level.

Note that Andrew Jones did work for KEF and even designed the TAD’s Reference with good coaxials.
Is not that he does not know about the subject, this time its obvious he has been limited by Elac budget or management.

 

[Gatordaddy]

Which base model?

The B6 or B6.2.

 

[Ron Texas]

Thanks for the great review. When the original UB-5 came out it was the most written about speaker that year. They are a much better deal than the slim version, although not as nice looking.

 

[AVKS]

I owned a pair of the regular (non-slim) UB5s that sounded very good in my room but caused ear fatigue and even pain that I couldn't attribute since I didn't listen loudly. Having never experienced that with any other speaker in my space (Studio530s, M16s, F35s, and others) I wonder if perhaps that distortion played a part and, if so, if other people have had the same experience.

Unfortunate really as I enjoyed them for the start of each session, before the fatigue and ache set in.

 

[QMuse]

Well, that pretty much makes three of us, although my measurement is full of room modes below 300 Hz, and I can't get as much resolution in the 2 kHz region with my setup. I didn't take any distortion measurements. That big hump centered at 1800 Hz blurred upper midrange, lower treble detail and ruined the speaker for me. I think this is a text book example of a designer overestimating the importance of smooth far-off axis response and underestimating the much more important early-arrival response.

IMHO, as both directivity curves are relatively smooth I don't see that as much of a problem as it can be easilly EQ-ed and the SQ would improve, but those distortion humps indicate a more serious problem with drivers which cannot be fixed.

 

[gr-e]

I wonder if distortion is caused by the crossover itself. A 300Hz crossover requires high value components, which means electrolytic caps and metal core inductors

 

[Ty55555]

Just curious. Do you listen before or after you perform the measurements?

 

[napilopez]

I don't see how you come to this sweeping statement. I'd say that there's simply a vast difference in R&D between coaxial as a gimmick and as a feature, as Genelec or KEF showed us.
Anyway, ELAC proved that it doesn't belong to the second kind and should content itself with making good/better traditional speakers.

Hence "tends to be" and "for a second time," referring to the previous elac tested, I assume.

The results so far prove that good coaxials are really hard to make, and only a few really get it right, as you say.

Budding audiophiles often do ascribe a type of magic to coaxials (I was one of them) because sound emanating from one point in space has to be better than spatially separated drivers. But as one learns more about speakers, the illusions break down, and one sees they have their compromises like any other design.

 

[Ty55555]

Preference Rating
SCORE: 5.0
SCORE w/ sub: 7.0

Sensitivity: 84.7dB
FR: +/-4.6dB 46Hz-20kHz ; +/-4.3dB 80Hz-20kHz
View attachment 66584View attachment 66585View attachment 66586View attachment 66587View attachment 66588View attachment 66589

Do you think it's a good idea to cross them over at 100

 

[q3cpma]

Budding audiophiles often do ascribe a type of magic to coaxials (I was one of them) because sound emanating from one point in space has to be better than spatially separated drivers. But as one learns more about speakers, the illusions break down, and one sees they have their compromises like any other design.

Except lower SPL due to the arrangement itself, I don't see any inherent minus to coaxials, personally. Even if I know you don't use it like this, the "every design is a compromise" mantra is very often used by those same audiophiles to justify regressive designs like 1st order crossovers, ignoring that all compromises aren't equal.

 

[MZKM]

Do you think it's a good idea to cross them over at 100

That could cause localization problems. The frequency response could go a bit lower, but distortion starts rising <60Hz, and since bass management crossovers aren’t instant, the standard 80Hz crossover would do nicely.

 

[Ty55555]

That could cause localization problems. The frequency response could go a bit lower, but distortion starts rising <60Hz, and since bass management crossovers aren’t instant, the standard 80Hz crossover would do nicely.

Thanks. Room correction had it at 100 and I changed it to 80

 

[Billy Budapest]

I wonder if distortion is caused by the crossover itself. A 300Hz crossover requires high value components, which means electrolytic caps and metal core inductors

The picture of the crossover posted in this thread revealed that two of the inductors appear to be iron core.