KEF LS50 Meta Review (Bookshelf Speaker) Video

[KMO]

Well analysed, like you say the Meta makes probably the smallest change to its acoustic output. Now about the 4c, it cannot be compared of course in terms of distortion due to being a 3-way and having also several woofers although above 200 Hz the Meta does quite well, especially considering its size.

I was certainly ignoring the bottom end, but above the 350Hz(?) woofer crossover point, it's still a big difference:

From the white paper, it seems the motor system managed to get the distortion down in the 600Hz-3kHz midrange significantly compared to the LS50 original, but we don't have comparable Amir measurements for that.

(Nice work cutting the horizontal scale off at 200Hz there )

 

[thewas]

I was certainly ignoring the bottom end, but above the 350Hz(?) woofer crossover point, it's still a big difference

Sure, it should be said though that the 4c values are really fantastic, beating almost all loudspeakers measured by Amir.

From the white paper, it seems the motor system managed to get the distortion down in the 600Hz-3kHz midrange significantly compared to the LS50 original, but we don't have comparable Amir measurements for that.

I had also done and posted some comparison measurements here, the improvement especially in the more problematic 3rd harmonic is quite impressive.

 

[BoredErica]

Sure, it should be said though that the 4c values are really fantastic, beating almost all loudspeakers measured by Amir.

I had also done and posted some comparison measurements here, the improvement especially in the more problematic 3rd harmonic is quite impressive.

A question I've always had regarding these thd measurements: If I'm using a sub w/ a steep crossover, will the relevant performance of the Metas be just everything to the right of the crossover frequency? Or will using a sub improve the thd performance of the speaker above crossover frequency because it was being held back in some way by having to produce low frequencies? I assume the former but want to know if it can't be the former.

Another point of clarification is with 96 vs 86db thd graphs side by side. In normal music higher frequencies are much lower db compared to bass. If I'm listening 85db at 1-2khz, bass thd performance will actually be like what's described in 96db thd graph because the bass will be louder. Right?

 

[thewas]

A question I've always had regarding these thd measurements: If I'm using a sub w/ a steep crossover, will the relevant performance of the Metas be just everything to the right of the crossover frequency? Or will using a sub improve the thd performance of the speaker above crossover frequency because it was being held back in some way by having to produce low frequencies? I assume the former but want to know if it can't be the former.

Another point of clarification is with 96 vs 86db thd graphs side by side. In normal music higher frequencies are much lower db compared to bass. If I'm listening 85db at 1-2khz, bass thd performance will actually be like what's described in 96db thd graph because the bass will be louder. Right?

Both times yes, your guesses are correct, for the first one though the intermodulation distortion would be reduced.

 

[Descartes]

You just need to bother spending the time going to Spinorama github, open up a tab for meta and one for ls50 and tab back and forth.

Spoiler

Meta is flatter here in that the dips and peaks are less but also the overall slope of the curve is closer to 0 vs LS50 which is going upwards.

Spoiler

LW is closer to on axis. Early reflections DI and even more so sound power DI is smoother with Meta. It is going up and down on Ls50.

Spoiler

Look at how much LS50 goes up past 4khz before coming back down. 1khz is more crushed too. Better directivity allows better EQing. This alone ends the debate.

Spoiler

Dispersion contours normalized:

Spoiler

These measurements are too different for you to start saying people who hear a difference are just suffering from placebo. Trained listeners can hear distortions many, many, many db below the average person. There are even tracks designed to tease out differences in tonality. If you think that peak of LS50 at 4-5khz is too high Q to be audible, then look at the dip on the LS50 from 400-600hz with a difference of 2db between the two.

You might not hear a difference and that doesn't mean your ears are broken. That's a perfectly reasonable statement to make. But you didn't want to stop there. All this time writing white papers and you don't know you're not supposed to compare two curves with different axises.

ok I'm done arguing with people who can't be bothered to read past the first graph in each review.

Thank you for that summary! I will definitely buy them and compare them with my own ears

 

[Crosstalk]

I then question why you made the mistake to buy unlistenable speakers in the first place. And live with unlistenable speakers 10 years.

At that time , they were what was avaialble as good speakers at the price point. Also back then a person like me never learned what is a good sound as ASR wasnt there and I never knew how to interpret the measurements . Now I know and now I lnow what is better. LS50 normal is good with eq. LS50 meta without eq is close to a monitor- Its more accurate to the input signal

 

[Kahana]

Time to update the main preference database?

 

[Descartes]

 

[Descartes]

The LS50W II are on sale 30% off on WOOT!

 

[Vacceo]

The LS50W II are on sale 30% off on WOOT!

If anyone is thinking about getting a soundbar, these speakers will tear any soundbar apart. If the price is right for you, do not hesitate on getting them!

 

[raceskier]

The LS50 Meta just went on Black Friday sale for $999.99 at all the usual KEF vendors.

 

[Digital_Thor]

Just EQ'ed my LS50 Meta. I found them to bright out the box. Now they measure like this, and seem way more enjoyable without the elevated tweeter, IMO.

In my room, it did not help at all to point them straight, rather than toe-in. I also tamed that 1800Hz bump. My EQ is as follows - if of any interest.

I feed it with a dedicated 200W amplifier and cross it at 300Hz a pair of 8" woofers that then smooth over to a set of 4 subwoofers. The little KEF has IMO zero output in the lows, and therefore strictly used as a midrange/tweeter solution. Unless maybe near-field on a desk.
Really like how it disappears in the sound stage, when the recordings allow it. Very neutral and free of pointing out "here I am" - like many non-neutral speakers tend to do.
Overall SPL is low though. So don't expect powerful dynamics - even with loads of power. But that's an ok price to pay for this little gem.

 

[Digital_Thor]

And this is what I get in a simple test cabinet with a KEF R midrange - SP1753AA:

 

[192kbps]

As explained, the preference score completely assumes far-field listening. Indeed we don't have one for near-field listing.

If you got that impression from "Near Field Scanner" that I use, I can see that but again, the reality is the opposite. The scanner uses near-field measurements to compute far-field results. Unless noted otherwise, everything I post is far-field.

For completeness, the standard stipulates "far field" to be 2 meters, reported at 1 meter. I have looked a number of speaker measurements and difference past 2 meters is negligible so it is as good as far fied. FYI I can generate results for any distance with my system. You may have noticed "10 meter" designation on directivity plots and such.

I heard that 10 meters is the default setting for NFS, but why 10 meters?