KEF LSX Review (Wireless Speaker)

[thewas]

I was thinking they wouldn't experience the tweeter boost at 8K (better shown on the Drive Components Near Field graph...) In any case, it's looking rather messy above 4K, where brightness can be a problem...

Those are nearfield not SPL corrected measurements where the influence of the driver size and waveguide isn't included, of listening relevance are the other measurements where the tweeter is rather subdued above 8 kHz:

 

[Mal]

The metamaterial tweeter absorber is great as a scientific research result and proof of concept (and also for marketing) but is probably one of the least audible improvements of the latest KEF innovations/evolutions, I wouldn't really miss it thus on the LSX (I own both generations of LS50) if all other driver, electronics and usability aspects are improved (hope there will be soon some measurements and white paper). Possibly they didn't use it also for product series hierarchy reasons.

So you say, but you might have high frequency hearing loss or have got used to the non-meta sound.

So we need objective results.

Look at the graphs for the KEF LS 50 Meta, the tweeter looks *much* more well behaved on KEF LS 50 Meta that the KEF LSX from 4K onwards.

KEF LS50 Meta Review (Speaker)

This is a review and detailed measurements of the KEF LS50 Meta bookshelf coaxial speaker. It was kindly purchased new by a member and drop shipped to me and costs US $1,500 for a pair. The LS50 Meta comes in different colors and I must say, it looks stunning in white: You could sell it as...

www.audiosciencereview.com

The 1 to 2K region of the KEF LS50 Meta is ??? - but no worse than KEF LSX...

Does the LS60 fix that?

 

[Mal]

Those are nearfield not SPL corrected measurements where the influence of the driver size waveguide isn't included, of listening relevance are the other measurements where the tweeter is rather subdued above 8 kHz:

I listen near field (about 1 metre away...) to try and avoid room problems as much as possible.

"Estimated in-room response (EIRR) is a technique used to predict how a speaker will sound in a room based on its on-axis frequency response and directivity data. It's generally considered more suitable for larger rooms and farther listening distances."

https://www.researchgate.net/publication/374696033_Immersive_Personal_Sound_Using_a_Surface_Nearfield_Source

 

[thewas]

So you say, but you might have high frequency hearing loss or have got used to the non-meta sound.

So we need objective results.

What are you talking about, I am basing my analysis purely on objective data while you try to correlate your personal listening experience to some wrong understanding of such.

 

[thewas]

I listen near field (about 1 metre away...) to try and avoid room problems as much as possible.

"Estimated in-room response (EIRR) is a technique used to predict how a speaker will sound in a room based on its on-axis frequency response and directivity data. It's generally considered more suitable for larger rooms and farther listening distances."

You don't need to tell me what the PIR is and above I also plotted the listening window plotted to show you the perceived direct sound which also doesn't show any increase above 8 kHz but rather the opposite.

 

[Mal]

The audio quality is excellent. They have a strong family resemblance to the LS50, with similar strengths (coherence and soundstage) and weaknesses (frequency extremes). Because I listen to them at much lower levels than when I had the LS50s in my main system, I actually get better bass extension.

For pure sonic quality I suspect the Neumann KH80 with a Sonos Connect or Wiim are superior. But they are small (good) and ugly (bad).

Can you expand on how KEF LSX are weak at frequency extremes in your estimation?

Amir's conclusions on the Neumann KH80: "The Neumann KH 80 DSP Monitor measures quite well and seems to be competently designed.. This may make it a very good fit for pro use in recording and mixing. For hifi listening though as I noted, I still prefer the JBL LSR305P. The JBL projects a larger image, has more bass performance and detail in mid-range. It is also cheaper. So personally I would not use the KH 80 DSP but you have the data to decide for yourself."

Does KEF LSX do better in image size, bass performance, and mid-range detail than these monitors. Are there other factors that make for better hi fi listening that the KEF does well or badly?

 

[MAB]

So you say, but you might have high frequency hearing loss or have got used to the non-meta sound.

You keep mentioning this to people, are you hoping your years are somehow better, immune from aging, or are you just dumping on people? It actually sounds more like an accusation, like you are trying to win an online argument. To be honest, when I hear people saying a relatively flat speaker sounds sibilant the first thing that comes to mind is they are listening too loud for the unit. I also have to wonder about the recordings being used to judge, except you seem to associate the artifacts to particular composers which makes no sense.

In the mean time, please stop accusing people of having bad hearing, nobody with any shred of hearing are likely going to hear the same artifacts in these speakers that you are claiming.

So we need objective results.

It would be good if you provided the objective results to actually have a conversation. The data is available, you can make the plots and educate, debate, litigate, and provide at least some evidence to support your claims. You have made quite a few subjective characterizations, like 'roller coaster', 'messy', etc. and asked people to go look.

Neither speaker fits any of your descriptions or comparisons. At your age no way the 1-2dB delta above 10kHz is going to matter one iota, and neither would lead to any of the effects you are suggesting. The difference in the midrange is real, likely audible, and changes a few degrees off axis, I'll leave it to you to look through the data to figure that out, and what one might do about it since those are going to be dependent on your room and setup and preference.

Look at the graphs for the KEF LS 50 Meta, the tweeter looks *much* more well behaved on KEF LS 50 Meta that the KEF LSX from 4K onwards.

KEF LS50 Meta Review (Speaker)

This is a review and detailed measurements of the KEF LS50 Meta bookshelf coaxial speaker. It was kindly purchased new by a member and drop shipped to me and costs US $1,500 for a pair. The LS50 Meta comes in different colors and I must say, it looks stunning in white: You could sell it as...

www.audiosciencereview.com

The 1 to 2K region of the KEF LS50 Meta is ??? - but no worse than KEF LSX...

Does the LS60 fix that?

Perhaps look at speaker response to address your personal concerns? LS60 data is available as well.
Even better, you should measure your own setup, find out what is causing you to perceive these artifacts, and address the issues.

 

[Mal]

I also have to wonder about the recordings being used to judge, except you seem to associate the artifacts to particular composers which makes no sense.

In the mean time, please stop accusing people of having bad hearing, nobody with any shred of hearing are likely going to hear the same artifacts in these speakers that you are claiming.

It would be good if you provided the objective results to actually have a conversation. The data is available, you can make the plots and educate, debate, litigate, and provide at least some evidence to support your claims. You have made quite a few subjective characterizations, like 'roller coaster', 'messy', etc. and asked people to go look.
View attachment 412861


Perhaps look at speaker response to address your personal concerns? LS60 data is available as well.
Even better, you should measure your own setup, find out what is causing you to perceive these artifacts, and address the issues.

I'm not associating brightness with particular composers! I said some of my classical music CDs sound bright with the LSXs that don't sound bright with my Senn HD 650s.

I can't hear a 10KHz test tone (I just found that out...) But your graph shows a roller coaster between 4 and 6K... that's the area I was most worried about, and I can certainly hear test tones over this area.

OK "roller coaster" is maybe hyperbole, but 4db down and then 4dB up between 4 and 6K... couldn't that be audible and explain some recording being perceived as brighter, or rougher, than a totally flat speaker/headphones?

Note, it's not just me saying some classical music recordings come across as bright on the lsx - check out John Atkinson's Stereophile links.

Measure my own setup? Using REW? Life's too short! I think I'll go and listen to more music instead, about 80% of my CDs sound fine on the LSX, I can listen to the other 20% on my Senns...

 

[MAB]

I'm not associating brightness with particular composers! I said some of my classical music CDs sound bright with the LSXs that don't sound bright with my Senn HD 650s.

I can't hear a 10KHz test tone (I just found that out...) But your graph shows a roller coaster between 4 and 6K... that's the area I was most worried about, and I can certainly hear test tones over this area.

OK "roller coaster" is maybe hyperbole, but 4db down and then 4dB up between 4 and 6K... couldn't that be audible and explain some recording being perceived as brighter, or rougher, than a totally flat speaker/headphones?

Note, it's not just me saying some classical music recordings come across as bright on the lsx - check out John Atkinson's Stereophile links.

Measure my own setup? Using REW? Life's too short! I think I'll go and listen to more music instead, about 80% of my CDs sound fine on the LSX, I can listen to the other 20% on my Senns...

You could have actually measured in less time than all of the posting you did, and the odd responses to a bunch of comments from 3 years ago. And you would have learned about what your speakers are actually doing in your room, and could have avoided the hyperbole. Same thing for your hearing, seems like you had it measured recently. A $30 measuring mic would tell you what is actually happening in your room. And why the HD650 with the 4dB dip at 7.6kHz might actually sound good to you. Note that headphone to speaker comparisons are fraught, but the HD650 do have a significant dip at 7.6kHz, please read the review and see the proposed EQ:

Do you use EQ on your headphones to try to get them to sound relatively flat? My guess is 'no'.

Roller coaster, as you say, is completely hyperbolic. Please avoid hyperbole, especially if you are unwilling to actually quantify. Perhaps go and look at many other speakers' midrange performance and get back to us on what 'roller-coaster' measurements really look like. These KEF models are good to great in the midrange. I would EQ your phones to flat, see if the 20% of your collection sounds more like your speaker. TBH, 20% of a classical collection with less than ideal recording quality is what most of us have to deal with. Recordings are often not good, the biggest variable in my setup, and most of my favorite music is less than ideal reproduction. I don't want to speculate too much, but my guess is your headphones are masking bad recordings. And perhaps you could learn about setup of your speakers.

 

[Mal]

Perhaps go and look at many other speakers' midrange performance and get back to us on what 'roller-coaster' measurements really look like. These KEF models are good to great in the midrange...

I find the mid-range to be very good, but worry about that dip at 5K. Erin reviewed the KEF LSX II LT, which measures very like the original KEFs. He also worries about that dip!

 

[Xyrium]

Hi, I still have them, and still love them. They've allowed me to appreciate music from 80Hz up, without feeling as if I need a sub, because my room is a train wreck even with REW and a PEQ. I've knocked one over from it's 1M perch, and it's got back on its feet and operated flawlessly. They are outstanding for the price, IMHO.

 

[Deleted member 85077]

Eerie how similar some reviews for the LT are.

 

[Ciccioilmoro]

Plus I think Amir tested that as a regular speaker and this as a desktop/computer speaker. Besides the resonances of the Q350, it seems Amir didn't like the narrow horizontal soundstage of the Q350; may be worthwhile to test the LSX as a regular speaker and see if he feels the same.

That said, the LSX has noticeably wider horizontal dispersion than the Q350, maybe due to using a 0.75" tweeter,

It's still using my old scaling, but here is the Q350:

And the LSX:

The LSX doesn't even go past -20dB. Plus it becomes more omni higher in frequency (~200Hz vs ~120Hz), so that likely helps as well.

 

[D700]

FWIW, I got the LT version at Costco for $500 and I’m kinda gobsmacked. These are pretty much perfect computer speakers…especially at the LT price. I’m debating a 2nd pair for small TV to replace Beam 2, which is fine for TV but the LT blows it away in stereo music.

 

[D700]

FWIW, I got the LT version at Costco for $500 and I’m kinda gobsmacked. These are pretty much perfect computer speakers…especially at the LT price. I’m debating a 2nd pair for small TV to replace Beam 2, which is fine for TV but the LT blows it away in stereo music.

and for anyone passing by using as desktop speakers on Mac, definitely set the Kefs for unity gain. Makes an audible difference. What a delight these are