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Elac Uni-Fi 2.0 Review (bookshelf speaker)

Rock Rabbit

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Interesting how the distortion from the port clearly shows the problem:
View attachment 104762

Seems like the cabinet is amplifying it and then comes out of the port? It does not show up as a port resonance.
But the port adds a third peak near 500 Hz.
The essential narrow double resonance seems a cone breakup mode and is even present at 86 dBSPL.
Is the effect of narrow peaks with intermediate dip to hide in the FR?
Eva Cassidy vocal range and guitar is all the time near resonance (d5 note), is a killer track for metal cone resonance!
 

tecnogadget

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I bet it must be a rattle sound of something loose as other members has pointed out. Don’t forget That even costing $600 this are still upper budget construction hifi speakers made in china, not the tightest tolerances out there. There are even +$1000 Speakers with disappointing tolerances, so please don’t take my comment as an specific attack. Lastly, even shipment could have been the cause of something becoming loose and not build quality.

IMD testing would be nice addition with concentric driver speakers, even if it turns out not to be the reason of that ugly sound. @amirm is it possible to add this kind of measurements?

I remember getting paranoid with my right surround speaker making a weird rattle with specific keyboard notes. It turned out to be rattling of the system used to attach them to the wall :p, the speakers were fine.
 

Sonny1

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Wow! Another great speaker review. I was intrigued by these speakers. They are the right size and price but it appears Andrew made an uncharacteristic mistake in the design. I hope it’s just a bad sample but it doesn’t appear to be. Thanks Amir for the excellent work you are doing.
 

awdelft

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thanks so much for reminding me why I listen to full range Mark Audio... great track
 

Prutser

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Seriously...?

Solid-state, monoblock power amplifier with proprietary "class-I" output stage. Inputs: 1 unbalanced (RCA), 1 balanced (XLR). Outputs: 2 pairs binding posts. Maximum output power (20Hz–20kHz, at <0.1% distortion): 500W into 8 ohms (27dBW); 1000W into 4 ohms (27dBW). Frequency response: 10Hz–20kHz, ±0.1dB. Input impedance: 100k ohms balanced, 50k ohms unbalanced. Voltage gain: 26.8dB. Output impedance: not specified. Input sensitivity: 2.89V input for full output. Signal/noise ratio: 85dB ref. 2.83V RMS (1W at 8 ohms).

I think perhaps it was a present from someone....

Maybe, sometimes, Amir makes a joke :) I think 52 in de name stands for 52000 dollar for stereo.
 

ctrl

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This is a case for the riddler! ;)

What is very strange is that the frequency analysis of the relevant part in the piece of music (Eva's inhaling) shows that 580Hz is not excited.
1610206309772.png
The resonance heard by @amirm should rather be at 440Hz (A4). But in this range the measurements do not show any abnormalities. Other excited frequencies are in the frequency range around 290Hz, 730Hz or 880Hz.

What happened?


Interesting how the distortion from the port clearly shows the problem:
Seems like the cabinet is amplifying it and then comes out of the port? It does not show up as a port resonance.

The 3% HD3 are most likely not caused by the port or woofer, since the crossover frequency is 200Hz. With a crossover of fourth order, the sound pressure is already damped over 30dB at 580Hz, even with second order crossover at 200Hz the damping of the woofer signal is already around 30dB.

So the only possible cause is the midrange driver (if you exclude other causes - for example uneven or loose screw connection of a chassis or the crossover board, external causes,... ).
 
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hardisj

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Resulting in this predicted in-room response:

index.php


One of my favorite things about all this science is trying to relate the prediction to what happens in the real world. I take measurements in my room via REW using the MMM and overlay those on the prediction from the SPINs.

I don't have the ability to measure these speakers myself but @joentell did in the review linked below and from this screengrab @ 13:41 you can see that his in-room measurements line up reasonably well with the predicted in-room response. So, just another set of data that goes to show how useful the SPIN data can be in providing readers a realistic idea of the response in their own room (proving the science isn't freaking voo-doo).

1610209873601.png







Link to vide where his data starts below.

 

BN1

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To be charitable to Andrew Jones I am going to guess there was a manufacturing error and parts were out of spec.
Ha, spoken like a true design engineer ! :p
 

617

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This adds more data to the growing pile that you can't rely on Brand as a proxy for quality. One speaker in the lineup performs really well and the next one is defective. Buyers will need to judge each speaker individually and make no assumptions that the quality of one model in any way translates to another. :(

Well, I wouldn't go that far. I don't think we've seen a poor performing Kali, Genelec, Neumann, JBL/Revel yet. KEF does well as well.

Also, how in the world did Andrew Jones become the only speaker designer people know by name? Not to take anything away from him, but it's very strange to me.

@amirm I'm not sure how much time you want to devote to this issue but you could stick a mic in front of the speaker when it is making this egregious noise, that might clarify the severity of the issue. Not something I'd normally suggest but it might be an interesting point for discussion.
 

617

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Ha, spoken like a true design engineer ! :p

When Kali was having some issues with their review they popped into the thread and broke down their whole QC process. One of the best all time ASR moments for me at least.

See here.
 

joentell

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When Kali was having some issues with their review they popped into the thread and broke down their whole QC process. One of the best all time ASR moments for me at least.

See here.
Charles Sprinkle is awesome. He's taught me a lot about the Moving Mic Method! He learned from Floyd Toole and Sean Olive when he was previously at Harman.
 

Rock Rabbit

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This is a case for the riddler! ;)

What is very strange is that the frequency analysis of the relevant part in the piece of music (Eve's inhaling) shows that 580Hz is not excited.
View attachment 104816
The resonance heard by @amirm should rather be at 440Hz (A4). But in this range the measurements do not show any abnormalities. Other excited frequencies are in the frequency range around 290Hz, 730Hz or 880Hz.

What happened?




The 3% HD3 are most likely not caused by the port or woofer, since the crossover frequency is 200Hz. With a crossover of fourth order, the sound pressure is already damped over 30dB at 580Hz, even with second order crossover at 200Hz the damping of the woofer signal is already around 30dB.

So the only possible cause is the midrange driver (if you exclude other causes - for example uneven or loose screw connection of a chassis or the crossover board, external causes,... ).
Inhaling notes (?), please add the guitar notes. There's D4 with harmonics D5 + inhaling (all at same time), move the window to include previous guitar notes (32768 points better resolution)
And effectively is the midrange metallic cone with a double resonance mode, typical membrane modes (modes 2.1 and 0.2 probably, 2.135f and 2.295f).
Obs.: your FFT shows d4 and a4...but instruments play harmonics ;-)
 
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Ron Texas

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Ha, spoken like a true design engineer ! :p
Funny, because my background is far from engineering. Maybe we will hear from the manufacturer about this.
 

JIW

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This is a case for the riddler! ;)

What is very strange is that the frequency analysis of the relevant part in the piece of music (Eva's inhaling) shows that 580Hz is not excited.
View attachment 104816
The resonance heard by @amirm should rather be at 440Hz (A4). But in this range the measurements do not show any abnormalities. Other excited frequencies are in the frequency range around 290Hz, 730Hz or 880Hz.

What happened?




The 3% HD3 are most likely not caused by the port or woofer, since the crossover frequency is 200Hz. With a crossover of fourth order, the sound pressure is already damped over 30dB at 580Hz, even with second order crossover at 200Hz the damping of the woofer signal is already around 30dB.

So the only possible cause is the midrange driver (if you exclude other causes - for example uneven or loose screw connection of a chassis or the crossover board, external causes,... ).

The -20 dB peak between 100 Hz and 200 Hz maybe contains the 5th subharmonic, i.e. 1/5 of the frequency, of the resonance, so it may be sympathetic resonance that is not masked by musical content.
 

Morpheus

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Are you still refusing to evaluate speakers in pairs? I continue to maintain those sort of subjective evaluations are meaningless and not useful to the consumer.

I think there is nothing subjective in measuring and listening just one speaker, and is logistically obvious. However, two reasons why you may have a point about measuring a pair... Firstly, two samples double the chance of catching something wrong in QC, even if they are presumably from the same batch, and we have seen QC issues aplenty surfacing here, certainly too much for comfort from consumer perspective.
Secondly, there is already discordance of some speakers with the subjective experience in mono vs what Amir expected drom the data. Even someone so bent on objectivity like Amir has aknowledged when he takes a listen afterwards and finds something he wasn't really expecting... So, those measurements tell us most, but not everything that is relevant to the way we perceive sound reproduced by transducers (not even taking in account room and psycoacoustics aspects wich are major influences). But the crux here, is that it always amazes me the trick our brain pulls when I hear a mono speaker or earphone, and then put the other on: the sudden illusion of a sonic scene is crazy, even more striking than going from 2D to quality 3D images for me ( I am familiar with those in medical imagery). That illusion is fundamental to me when I listen, almost so as a balanced frequency response and only happens when another transducer is in play. I would rather have a pair of speakers with minor issues in frequency response but that creates soundstage, or should I say, lays down the foundation from my wich my ear apparattus/brain processing creates such, than the reverse. So, if we see some speakers/headphones that from the measurements should sound the same in mono, and in mono already shows subjective discordance with data for even an objectivist to remark on, what can we expect when some of the tecnhical aspects we already know are relevant to the creation of that illusion (individual sensitivity and frequency response matching, phase response absolute and relative between both units for example), are neither taken in account in measurements, nor subjectively tested at the end..? Not so much as a tottaly wrecked FR, but a lot anyway..
Yes, mono is nice, but stereo is what it is all about for me, and I believe most. One of the most important aspects of that sepaker enjoyement gets left out, it seems.
However, all in all, I understand Amir position in this.
You and I are not managing schedulling, contacting, pick up and deliveries, hauling gear up and down and in and out , measuring the whole thing twice, fronting and managing this show, so Amir's decision is an obvious one. Gets the most relevant techical aspects in far more reliable, in-depth and breadth done than any other site I am aware of (no boot licking here intended, just tell it like I see it, ok? ) in what should be logistically already rather troublesome, but would be so much more if it had go double the trouble for every speaker and slow things down...At least headphones don't suffer from this. :)
 
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joentell

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This reminds me of an issue I had with the original UB5. The concentric tweeter was slightly off-center inside the midrange driver and at just the right frequency, the aluminum cone would touch the tweeter housing and make a nasty sound. If I hadn't done some sweep test with a generator, I wouldn't have easily discovered it since it was only activated in a narrow frequency range that was rarely touched in most songs.

I reseated the tweeter and the problem went away. I'm wondering if the tweeter was dislodged in shipping maybe?
 

DualTriode

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Interesting how the distortion from the port clearly shows the problem:
View attachment 104762

Seems like the cabinet is amplifying it and then comes out of the port? It does not show up as a port resonance.

This is the the type of malfunction that brings the engineer out in me.

What is making this noise, is the question in me? What to do to change the character of the noise?

Is it velocity noise as in air rushing past some physician feature of the port or box?

Try stuffing a wee bit of polyester pillow stuffing back into the sharp edges of the port to change the velocity flow . Be sure to tie a piece of string on the stuffing so you can pull it back out. This is Robert Pease style of trouble shooting.

I can spell amirm correctly.

Thanks DT
 
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YSC

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This reminds me of an issue I had with the original UB5. The concentric tweeter was slightly off-center inside the midrange driver and at just the right frequency, the aluminum cone would touch the tweeter housing and make a nasty sound. If I hadn't done some sweep test with a generator, I wouldn't have easily discovered it since it was only activated in a narrow frequency range that was rarely touched in most songs.

I reseated the tweeter and the problem went away. I'm wondering if the tweeter was dislodged in shipping maybe?
if that's the case then it's kind of sad for concentric designs.. we all know how fedex and UPS handle packages..
 
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