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Elac Reference UCR52 Review (Center Speaker)

amirm

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This is a review and detailed measurements of the Elac Unifi Reference UCR52 center home theater speaker. It was kindly purchased new by a member and drop shipped to me. The UCR52 costs US $700.

The UCR52 enclosure is nice looking but I don't the wisdom of having highly reflective, chrome polished rings around a speaker in a theater application:

Unifi Reference UCR52 Review Center Home Theater Speaker.jpg


Even during music listening I found the reflective edges eye catching in the wrong way. There is a magnetic grill so you can hide them.

This is a three-way speaker with dual woofer and a mid-range+tweeter coaxial/coincidental driver. 3-way is my preference for center speaker to avoid directivity dips with so called MTM 2-way speakers.

Back panel sports very nice looking and feeling binding posts:

Unifi Reference UCR52 Review back panel binding posts Center Home Theater Speaker.jpg


Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Using computational acoustics, far-field response is computed and that is what I present. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber.

I performed over 1000 measurement which resulted in error rate of about 1%.

Reference axis is approximately the center of the tweeter. Grill was not used.

Unifi Reference UCR52 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

Unifi Reference UCR52 Measurements Center Home Theater Speaker.png


Wow, I must say, I did not remotely expect to see such a rough frequency response. It has both macro and micro level variations all over the place. Near-field measurements of each sound radiating elements explains some of this:

Unifi Reference UCR52 Measurements Driver Center Home Theater Speaker.png


Notice the very uneven response of the coaxial driver. We also have a port/cabinet resonance around 1 kHz. Let me jump ahead and show you distortion response:

Unifi Reference UCR52 Measurements THD distortion Center Home Theater Speaker.png


Unifi Reference UCR52 Measurements distortion Center Home Theater Speaker.png


When I was measuring the speaker I distinctly heard a sharp sound coming part way through the sweep. Note that I wear strong hearing protection so normally don't hear problems with speakers unless they are very severe. And this was. I got close to the speaker and put my hand on the cabinet. Right when I heard the output of norm, higher pitch sound, I would also feel the cabinet resonating. This occurred with the 96 dBSPL sweep. So I looked and saw that large peak between 500 Hz and 1 kHz. So I created a sweep that only excited that range of frequencies and I could hear the tone again.

Last time I reported a resonance like this it too was an a Elac speaker, the Unifi 2.0. There was a lot of doubt then as to whether this was really there so I decided to make a recording of the sweep. I used my phone to see if it can capture it and it did. See the sample zip file. Here is the amplitude evenelop:

Unifi Reference UCR52 Resonance Sound Sample Center Home Theater Speaker.png


You can clearly see the amplification of the tone before the sweep ends. If you play the audio file in an audio workstation software, you can easily hear the zing at the end in sync with that peak.

I tested this at 86 dBSPL and it was harder to hear it there.

Anyway, back to our measurements, here is our early window reflections:


Unifi Reference UCR52 Measurements Early Window Frequency Response Center Home Theater Speaker.png


Response is thankfully smoothed out due to a number of reflections being summed but we still have a shelving of upper bass and midrange. This results in the same issue in predicted in-room frequency response:

Unifi Reference UCR52 Measurements Predicted in-room Frequency Response Center Home Theater Sp...png


Horizontal beamwidth is pretty uneven but fairly wide in mid-frequencies:

Unifi Reference UCR52 Measurements Horizontal Beam width Center Home Theater Speaker.png


Same is seen in the colored contoured version:

Unifi Reference UCR52 Measurements Horizontal Directivity Center Home Theater Speaker.png


There are sharp edges around the metal the surrounds the coaxial driver. So I wonder it is causing some diffractions here that we see at the edge of our envelop.

Strangely vertical directivity looks better even though it audibly is not as significant:

Unifi Reference UCR52 Measurements Vertical Directivity Center Home Theater Speaker.png


I guess it doesn't have two woofers flanking it like the horizontal plane does.

The three snapshots I take land in the sweet spot of the speaker so show good response:

Unifi Reference UCR52 Measurements 3-d Horizontal Directivity Center Home Theater Speaker.png


Impedance dips to 5 ohm so make sure you have a decent amplifier to drive this speaker:

Unifi Reference UCR52 Measurements Impedance and phase Center Home Theater Speaker.png


Note that our resonance shows up clearly here as well in both phase and amplitude response.

Elac Uni-fi Reference UCR52 Listening Tests and EQ
Having seen the measurements in advance, I expected poor sound but did not get it. What was there was quite pleasant with very good dynamic ability. Wondering if I had lost all ability to subjectively assess speakers, I went ahead and put in a couple of filters to deal with that step up response between 200 and 1000 Hz:

Unifi Reference UCR52 Review Coaxial Center EQ Home Theater Speaker.png


At first, the difference was subtle but then I listened for 15 minutes and then turned off the EQ. Wow, so much muddier and a bit tubbier without EQ. Vocals came forward now which is what you want in a center speaker.

Conclusions
I know the word "reference" has been bastardized in audio to almost mean nothing but still, I expected more, far more from Elac and Andrew Jones. What were they thinking? How could they produce such a technically flawed speaker? When I can hear a resonance with hearing protection in a simple log sweep, surely they could too. Do they only play at low and modest levels and don't hear such things? If so, what is up with the uneven frequency response? Is this all tuned by ear? Why is it so uneven anyway? Was this pushed out the door before being finished? Lot of questions.

Thankfully or not, in a battle of subjectivity vs objectivity, with a bit of EQ it performs a lot better than it should. Dual woofers give it high SPL playback ability which is an effective way to get on my good side. :) This is super important in home theater applications were the center speaker carries most of the burden as it has to show all that is seen on screen.

On the resonance, I could not get a clear case of it showing up. Either I was not playing loud enough or that the tone was getting added to other parts of the music and it was not as obvious as it was in Uni-fi 2.0.

Anyway, I think technically the ELAC Uni-fi Reference UCR52 is a failure and I can't recommend it. Subjectively, with some EQ it can be made to sound good. You get to decide which side of me you want to believe. :)

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

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

Attachments

  • Unifi Reference Center.zip
    59.9 KB · Views: 24
  • Unifi Reference UCR52 Resonance Sound Sample.zip
    33.4 KB · Views: 19

Alice of Old Vincennes

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Hmm You're Infinity RC263 review was simply placid in comparison. Could be that Harman has it nailed. Maybe this is why Harman does not utilize concentric? 263 is simply best center I have experienced. I am not including Revel 3 way. Too expensive for me.
 

Vovgan

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Back panel sports very nice looking and feeling binding posts

One important question in the minds of many audio lovers that has not been assessed here yet is whether bi-amping makes any difference.

Center speakers like this are mostly used with AVRs that have too many amps for most users and thus give the option to bi-amp.

Bi-amping can potentially be assessed for the impact on:

1. Distortion levels
2. SPL at the same AVR volume
3. Frequency response

If there is time and interest to perform such analysis on this or any other speaker supporting bi-amping this would be super appreciated!
 

alex-z

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Hold up, are the distortion graphs correct? How is the 1300-2000Hz region improved at 96dB vs 86dB? Also, the 5000Hz peak got smaller?

Either way, pretty sad performance. Looks like KEF still has the coaxial market cornered, and with better cabinetry too.
 

Tks

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Are resonanaces really that hard to rectify?
 

Sancus

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Ouch. That doesn't look great. I'm honestly surprised at how poor it looks. The other "Reference" model measured way better.

Well, this is the coaxial line(Uni-Fi), and all the Elac coaxials have been disappointing, so I expected this one to be bad as well. As we've seen, getting a coaxial right is not easy. Considering the pricing on this "reference" version($600-700/channel) you should just dig a bit deeper in the piggy bank and go Kef IMO.
 

pavuol

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I know the word "reference" has been bastardized in audio to almost mean nothing...
Although a product category I have little interest in, due to Amir's humor many such reviews worth reading.. :)
Anyway, I think technically the ELAC Uni-fi Reference UCR52 is a failure and I can't recommend it. Subjectively, with some E it can be made to sound good. You get to decide which side of me you want to believe. :)
reminded me this old movie haha..
 

pierre

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Score 4.0 and 5.3 with an EQ.

filters_eq.png


The EQ will change the PIR and SPIN:
filters_pir.png
filters_spin.png


Here is the EQ in APO format:
Code:
EQ for Elac Uni-Fi Reference UCR52 computed from ASR data
Preference Score 4.0 with EQ 5.3
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.13
Dated: 2021-10-09-07:02:00

Preamp: -4.5 dB

Filter  1: ON PK Fc   509 Hz Gain -2.47 dB Q 1.10
Filter  2: ON PK Fc   169 Hz Gain +1.95 dB Q 3.87
Filter  3: ON PK Fc   280 Hz Gain -1.95 dB Q 5.16
Filter  4: ON PK Fc  1671 Hz Gain +2.10 dB Q 2.87
Filter  5: ON PK Fc   200 Hz Gain +0.68 dB Q 6.00
Filter  6: ON PK Fc  5178 Hz Gain -1.02 dB Q 3.87
Filter  7: ON PK Fc  1004 Hz Gain -1.18 dB Q 6.00
Filter  8: ON PK Fc 14143 Hz Gain +4.34 dB Q 2.57
Filter  9: ON PK Fc  3087 Hz Gain +1.28 dB Q 4.47

If you want other EQs:
Score 5.2 with max Q == 4
Code:
EQ for Elac Uni-Fi Reference UCR52 computed from ASR data
Preference Score 4.0 with EQ 5.2
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.13
Dated: 2021-10-09-07:06:06

Preamp: -4.5 dB

Filter  1: ON PK Fc   509 Hz Gain -2.47 dB Q 1.10
Filter  2: ON PK Fc   169 Hz Gain +1.96 dB Q 3.87
Filter  3: ON PK Fc   280 Hz Gain -1.70 dB Q 4.00
Filter  4: ON PK Fc  1671 Hz Gain +2.10 dB Q 2.85
Filter  5: ON PK Fc   200 Hz Gain +0.59 dB Q 4.00
Filter  6: ON PK Fc  5178 Hz Gain -1.02 dB Q 3.87
Filter  7: ON PK Fc   997 Hz Gain -0.90 dB Q 4.00
Filter  8: ON PK Fc 14143 Hz Gain +4.34 dB Q 2.57
Filter  9: ON PK Fc  3089 Hz Gain +1.21 dB Q 4.00

Score 4.8 with max Q == 3
Code:
EQ for Elac Uni-Fi Reference UCR52 computed from ASR data
Preference Score 4.0 with EQ 4.8
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.13
Dated: 2021-10-09-07:08:47

Preamp: -1.8 dB

Filter  1: ON PK Fc   509 Hz Gain -2.47 dB Q 1.10
Filter  2: ON PK Fc   168 Hz Gain +1.71 dB Q 3.00
Filter  3: ON PK Fc   280 Hz Gain -1.46 dB Q 3.00
Filter  4: ON PK Fc  1018 Hz Gain +0.50 dB Q 0.31
Filter  5: ON PK Fc   726 Hz Gain -1.18 dB Q 3.00
Filter  6: ON PK Fc   192 Hz Gain +0.50 dB Q 3.00
Filter  7: ON PK Fc  1664 Hz Gain +1.49 dB Q 3.00
Filter  8: ON PK Fc  5178 Hz Gain -1.12 dB Q 3.00
Filter  9: ON PK Fc  1021 Hz Gain -0.79 dB Q 3.00
 
Last edited:

GWolfman

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Missing something so obvious as that resonance makes me feel like there are other corners cut that they're hoping we won't discover. How can you let something like that out your door with your name & reputation on it? :eek:
 
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