There have been several rave reviews of this speaker and I recently purchased a new pair of the UB52s. I haven't been able to hear the resonance amir described. My conclusion was based on listening tests using the Eva Cassidy track and tone generator very slow sweeps from 550 to 650 Hz. The sweeps were performed at quite high SPL.This is a review and detailed measurements of the Elac Uni-Fi 2.0 bookshelf speaker. It was kindly sent to me by a member and costs US US $600 a pair on Amazon including Prime shipping.
This review will be abbreviated for reasons that will become apparent later.
Here is a shot of the speaker:
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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. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
I performed over 1000 measurement which resulted in error rate of less than 1% through majority of audible band.
Temperature was 59 degrees F. Measurement location is at sea level so you compute the pressure.
Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.
Reference axis was the tweeter center.
Elac Uni-Fi 2.0 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:
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Hmmm, seems like we keep hitting on speakers that shelf the mid to highs for some reason, this type lowering it. I checked other reviews and this matched another measurement posted so it is not instrumentation error.
Early window aggravates this some:
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Resulting in this predicted in-room response:
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Strange to see a mass market product opt for this type of high frequency output as it is opposite of conventional retail wisdom of "what sells in a showroom."
Distortion-test shows some issue around 600 Hz:
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It is a resonance that also appears in impedance graph:
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Edit: adding directivity information:
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Speaker Listening Tests
I always start my testing with select few female tracks as they quickly tell me if the speaker is too bright, lispy, etc. The first couple of tracks sounded fine but then I played the third standard track, the Eva Cassidy Ain't no Sunshine. Right at the marker something bad happened:
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She takes a breath and starts singing. On Elac Uni-Fi I heared a rather loud squeak instead of that breath! I can't it to words but the artifact actually sounded louder than her voice which came on an instant after that.
I remember during the measurement prep, I could hear a high pitched sound in the middle of the sweep. Thought maybe this was the same thing. To narrow down the frequency, I cut off everything above 1 kHz and problem remained. I inverted and cut off the lows and problem went away. I got it close to around 600 Hz but couldn't get the exact frequency. So went back to the distortion graph and found that frequency and notched it out:
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90% of the problem vanished! This speaker uses a new woofer and seems like it has a nasty resonances in this area that Eva's breath energizes. The artifact can be heard on the youtube version but not as strongly:
I stopped testing at this point. As a confirmation, I played the same track on Revel M105 and it sounded wonderful with zero issue (I have used the same track to test at least 100 speakers).
What a shock to discover what I did with this speaker. Usually resonances color the sound. They don't become instruments on their own. But that is what happened here. And in a design from the talented Andrew Jones. Given how easy it was to detect the issue in multiple measurements, it should have been caught and fixed.
As far as I am concerned, this is a show-stopper, broken design. Don't know how else to put it. FYI Eva Cassidy album is standard issue at all audio shows in multiple suites so it is not like it is some oddball track one never sees. I guess it is possible this one speaker sample has an issue in which case I encourage Elac to try to replicate this problem and let us know what is going on.
For now, I can not recommend the Elac Uni-Fi 2.0.
As always, questions, comments, recommendations, etc. are welcome.
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I really believe amir may have received a defective sample. Is Andrew Jones or EPIC following up on this? Have other members reported problems? I really hope we see some additional tests on other samples.