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KEF Q350 Speaker Review

73hadd

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I don't doubt for a second that wide dispersion is universally a good thing when listening to stuff in mono, but Toole's research shows quite clearly that those differences attributed to mono almost vanishes in stereo.

View attachment 64538



This graph shows the importance of not assuming too much when it comes to any one particular trait because one factor may not be that important when you introduce other factors. I agree completely with @andreasmaaan that we need to evaluate only high quality speakers with different dispersion to get any clear answer.
In order to do that with any relevancy to real-life situations, we also need to do that with a wider room and a smaller room to see if any preference between dispersion width is universal or situation-based.

We are in a situation where the absolute best "Toole-style" speakers almost by default will be coaxials and, because of that, the dispersion pattern in the theoretical "best" will be somewhat limited by the necessary size/shape of the coaxial drivers.
It makes no sense whatsoever to have the "perfect" speaker with regards to the preference score if it's nowhere near the top of the subjective listening evaluations due to limited dispersion.

I think this is REALLY interesting and I have a lot of questions and comments on this topic. Rather than extend the q350 thread, is there already a "coaxial and Toole" thread or should we start one? Questions about the "moving waveguide" in a coaxial - is it really a problem? Is that why it seems they limit the midrange excursion? I am sold on the coaxial concept as, in my unscientific guess, the point source design and time domain accuracy leads to some really interesting depth. Interesting that it can meet all the Toole design specs on paper but doesn't seem to make the top of perception?
 

QMuse

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I'm finding that hard to accept given it's for some mythical typical room

PIR's LF response is given as speaker is sitting in the middle of mythical typical room. As room gain and boundary reinforcement effects vary to a great extent between rooms it was the only choice they had to put into the CEA-2034 standard.
 

tecnogadget

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I think this is REALLY interesting and I have a lot of questions and comments on this topic. Rather than extend the q350 thread, is there already a "coaxial and Toole" thread or should we start one? Questions about the "moving waveguide" in a coaxial - is it really a problem? Is that why it seems they limit the midrange excursion? I am sold on the coaxial concept as, in my unscientific guess, the point source design and time domain accuracy leads to some really interesting depth. Interesting that it can meet all the Toole design specs on paper but doesn't seem to make the top of perception?

There's an "experience & preference" thread dedicated to coaxials but it's not very focused on its correlation with Toole's research. That would be a nice discussion topic.

As for the "moving waveguide" it has already been discussed in another review (can't find the specific link) as the effect being minimal/negligent if it is a 3-way setup as the R3 since the midrange driver does not really move much. In this particular case where the UniQ is also loaded with bass frequencies, I suppose it could yield some issues, mostly IMD, but I don't really have data to back it up.
 

Robbo99999

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It seems like a bit of a mess from 600Hz all the way up to 1500Hz, which is a critical area for voices and other instruments I believe, so I imagine that the fluctuations couldn't have really happened in a worse place in the frequency range. Not surprised to see an unenjoyable subjective listening experience.
 
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amirm

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I think KEF should have performed a formal double blind listening test to show the merits of coaxial drivers given how much they rely on it.
 

QMuse

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I think KEF should have performed a formal double blind listening test to show the merits of coaxial drivers given how much they rely on it.

And what would they do if results turn out to be less than stellar? :D
 

Haint

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It seems like a bit of a mess from 600Hz all the way up to 1500Hz, which is a critical area for voices and other instruments I believe, so I imagine that the fluctuations couldn't have really happened in a worse place in the frequency range. Not surprised to see an unenjoyable subjective listening experience.

Yea I think there's merit in that theory, seems to make a lot of sense.
 

Jon AA

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Totally fine to be skeptical about that, though I'm not sure that there's really a shifting hypothesis as much as it is just following what Toole says on the matter, and that there seems to be a trend with Amir's preferences (which for this review he specifically noted the identifiable source as potential issue).
And yet, even within Amir's subjective listening, the trend is not a rule. After EQ he quite enjoyed the Klipsch RP-600M and seemed more enthusiastic about it than some of these KEFs. That speaker is much, much more narrow dispersion than any of the KEFs. It's smooth and well controlled, but very narrow and not constant.
 

Robbo99999

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Yea I think there's merit in that theory, seems to make a lot of sense.
Yes, I see now that a few others have mentioned the same thing. I read the review and then posted my impressions without reading any of the comments because I didn't want to be swayed by them...but I've read all of them now!
 

napilopez

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And yet, even within Amir's subjective listening, the trend is not a rule. After EQ he quite enjoyed the Klipsch RP-600M and seemed more enthusiastic about it than some of these KEFs. That speaker is much, much more narrow dispersion than any of the KEFs. It's smooth and well controlled, but very narrow and not constant.

True thing, and it's not a constant for me either :)
 

QMuse

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And yet, even within Amir's subjective listening, the trend is not a rule. After EQ he quite enjoyed the Klipsch RP-600M and seemed more enthusiastic about it than some of these KEFs.

According to his own words @amirm 's preference is also based on his state of hunger. As we only recently learned that we cannot judge his previous listening tests.
 

Thomas savage

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I think KEF should have performed a formal double blind listening test to show the merits of coaxial drivers given how much they rely on it.
It's a technical feat but imo it's shite . It's like a boxer that dose you tube videos showing all these great skills but when they get in the ring they get knocked out.
 

Juhazi

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Harman has been focusing more on headphones, which makes sense in the current market and the existing body of knowledge.

Yes, and notice the last updates of Musings by Olive - date and topics http://seanolive.blogspot.com/

About directivity and preference. Seems to me that USA people prefer wide and smooth directivity and Europeans narrow and smooth. Asians are not systematic (in my view at least...). This might have something to do with typical room size and construction (reflectiveness)

About preference ratings based on measured data - I don't even look at those... But it takes some learning and testing to be able to do your own ratings from published measured data.
 

tecnogadget

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But then again what about the 2014 & 2018 R series, The Reference, Blade's, 201/2, etc? All proven good designs with great performance at their pricepoint/release time. And let's not forget Erin's own measurements of the raw drivers, they perform.

I think the subject of the debate should not focus on being coaxial or not, pro-UniQ or against. IMHO what seems to happen with the latest Q series reviewed is that you can only get X much of those drivers/tech when cutting corners and making budget lines.
It's like their goal for embedding them with the same tricks of higher series backfired.
 

napilopez

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On the other hand, their speakers are well-liked, they seem to universally measure well in their product categories, they cite Toole in their own whitepapers, and they sell well to boot. Seems like a pretty good combo to me.

I'd love to hear more about KEF blind tests though. And conversely, I've always found it curious that KEF speakers never seem to come up in available data on Harman blind tests, since they're such popular speakers. Might just be because most of that information seems to be pretty old and maybe KEF wasn't as popular in the US back then. But still.
 

Gatordaddy

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But then again what about the 2014 & 2018 R series, The Reference, Blade's, 201/2, etc? All proven good designs with great performance at their pricepoint/release time. And let's not forget Erin's own measurements of the raw drivers, they perform.

I think the subject of the debate should not focus on being coaxial or not, pro-UniQ or against. IMHO what seems to happen with the latest Q series reviewed is that you can only get X much of those drivers/tech when cutting corners and making budget lines.
It's like their goal for embedding them with the same tricks of higher series backfired.

In terms of preference score of speakers ASR has measured, these are only beaten by the Elac Debut References when considering speakers in the same price point. Considering the wide popularity of these speakers and their solid measured performance, it seems like KEF did a pretty good job of designing the uni-q into a lower cost speaker.
 

aarons915

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KEF do pretty well in blind testing from what I've seen. This article compares about a dozen budget bookshelf speakers and the Q150 was the overall winner and the Upgrade pick. They mention how they evaluated but it was blind with a switcher capable of instantly switching between 3 pair of speakers at a time.

https://thewirecutter.com/reviews/best-bookshelf-speakers/
 
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