KEF LS50 Meta Review (Speaker)

[digitalfrost]

What's your experience with highpassing the LS50? It makes sense in a large room but did you also notice any big improvements with a desk setup?

I had a similar experience that I liked the LS50 better at first without highpass. But the thing is, at least the original LS50 as the bass reflex tuning frequency somewhere around 60hz. That means the case is acoustically open below that, i.e. there is no air cushion that limits the woofer movement. There has been a lot of talk about the downsides of doppler distortion with coax chassis in this forum. The key for me was to move to 24db/oct crossover and put the crossover point higher, 100-120hz. That ended up making it better.

 

[juliangst]

I had a similar experience that I liked the LS50 better at first without highpass. But the thing is, at least the original LS50 as the bass reflex tuning frequency somewhere around 60hz. That means the case is acoustically open below that, i.e. there is no air cushion that limits the woofer movement. There has been a lot of talk about the downsides of doppler distortion with coax chassis in this forum. The key for me was to move to 24db/oct crossover and put the crossover point higher, 100-120hz. That ended up making it better.

I did all the testing and all my listening with the port plugs in place. The LS50 roll off at around 75Hz with this setup

 

[Burgunder]

That is a much bigger room than mine. How far away is you listening postion? At what volume level does it get to 76dB? Probably really low volume and easy to reach for any amp, like 2W maybe? Yeah iPhones have much more precise SPL apps.

I'm about 4 meters away when I'm working as this is my office, and 2 meters for more critical listening.

I'll normally have the volume at 34 sometimes 38 and at 40 a few times. I've seen that other users have noted distortion when the volume passes 44 but I've never gone that high. I'm mostly listening to classical rock with Black Sabbath and Led Zeppelin being the "hardest".

 

[Ciobi69]

guys i got a question, if you had to chose between the kef r3 and the ls50 meta for surround, what would you take? the kef r3 are more perfomant but the ls 50 are way smaller which i prefer, the cutoff will be 80hz in the crossover for the subwoofer, what would you take?

 

[Tangband]

High-pass LS50+ sub vs classic setup:

People always say that you need to highpass your mains so I tried that as well. I don't have a multichannel interface so I used 2 DACs with Voicemeeter.
I used a 80hz, 24dB/oct crossover and created flat filters from 25-400Hz using REW.

The red graph is exactly this setup. The blue graph is a 'classic setup' with the sub connected to the pre-outs of my integrated amp and crossover set to about 75Hz. The classic setup also has it's own flat filters.

Measurements were done with RTA and pink noise.

I can't really see a big improvement with the usage of highpass filters here. It's a bit flatter but that could be easily fixed with better filters.
I also prefer the sound of the 'classic setup'. It sounds more 'cohesive' and I cannot localize the sub. With the high-passed setup I actually hear where the bass is coming from.

I don't really need the headroom advantage of the high-passed setup because it's just a desk setup with a maximum SPL of 75-80dB at 1 meter.
I also prefer having a physical control like the volume knob of my integrated amp. With a highpassed setup I would need a 4 channel interface that has a master volume control. My pick would be the Focusrite Clarett +2Pre but that's another 400 bucks that don't really give my any huge advantage over my current setup.

What's your experience with highpassing the LS50? It makes sense in a large room but did you also notice any big improvements with a desk setup?



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If you like the sound without HP filtering for the main speakers thats fine..

But Im sure that a proper HP crossover and LP for subwoofer and main speaker gonna sound even better .
The problem is :

1. Most owners of gear have the wrong order of crossovers- a closed box main speaker falls theoretical with 12 dB/oct acoustically below the box resonance frequency . If you do HP with such loudspeaker electrical 24 dB then you will in real life have a 36 dB crossover for HP ( 12+24 ) . Using this with a subwoofer with 24 dB/oct LP crossover gonna be less than perfect. And then the room mess up things….

2. Below the schroeder frequency, the power response gets slightly better with an odd order HP and LP crossover , i.e. 6 dB, 18 dB , or 30 dB crossover. Many subwoofer dont have that. And the owners of the gear dont have a clue.
A good standalone dsp crossover have those options.

3. Even If the slopes of the crossovers are perfect , the crossover used might not be transparent enough in the sound quality, i.e it gonna sound best without a HP filter. One such example is the cheapest minidsp. Its not good enough in transparency, except for the bass.

4. With a transparent crossover with the correct order of slopes HP / LP, you get the ability to play much louder without distortion. Crossing at 80 Hz HP can lower the main speakers distortion even with silent music and this is audible, lowering especially IMD distortion.

 

[Daka]

guys i got a question, if you had to chose between the kef r3 and the ls50 meta for surround, what would you take? the kef r3 are more perfomant but the ls 50 are way smaller which i prefer, the cutoff will be 80hz in the crossover for the subwoofer, what would you take?

Distance - if closer go with LS50 meta they have wider dispersion if further than R3 (9-10 feet at least)

 

[juliangst]

Agreed. For 3 meters or more I'd go with the R3 for more headroom and more SPL in general. But for anything below that LS50 should be fine. They're smaller, look better, have better dispersion and are less expensive.

 

[Ciobi69]

Distance - if closer go with LS50 meta they have wider dispersion if further than R3 (9-10 feet at least)

I think they will be used to a maximums of 1.5 meters

 

[Alexium]

R3 is objectively better on all metrics, but Amir didn't like it while he did like LS50 Meta. That is very odd and confusing.

 

[juliangst]

R3 is objectively better on all metrics, but Amir didn't like it while he did like LS50 Meta. That is very odd and confusing.

Well, at the end your ears decide and not artificial Klippel measurements. Depending on your room and preference I can totally see the LS50 winning over the R3

 

[Alexium]

Very interesting notes on R3 at the end of this review which I have just randomly read: https://www.audiosciencereview.com/forum/index.php?threads/revel-f35-speaker-review.12053/
@amirm Would you perhaps consider adding this info to the R3 review? To let people know that speaker is not as bad as your initial impression, but requires tuning.

 

[pablolie]

I think speakers deserve a special position in the "measurement wars". With stuff like DACs and Amps the measuring criteria stay within a very easily definable interface aka reference point with all-electrical equipment. With speakers the measurements get way more complicated given all the spatial variables.

The fact that KEF offers all these speakers clearly shows they are not really in competition to each other - they simply target different use cases. All measure great enough that it's simply your own fault if you can't get them to sound great in your listening environment.

I have lived with many of these KEF speakers, so my short takeaway is...

1. The R3 are a great do it all. They provide enough everything to be an enormously versatile tool, but perhaps not the sharpest one for every use case.

2. The Reference 1 are superb speakers. In many cases they can act as full-range, seriously. They need a slightly larger room to shine, they are not small bookshelves.

3. The LS50 remain mind-blowing value. In the right room and with the right attention to detail, they also may be the most versatile in allowing for audiophile sound. Their size makes their optimal positioning easy, their design offers itself to optimize bass response for the use case.

Unlike the other 2, the LS50 will sound at its best if offloaded from stuff below 80Hz. The other two were designed to have solid bass response, so if you offload it from them, you end up paying for special design considerations you're not fully using.

 

[thewas]

R3 is objectively better on all metrics, but Amir didn't like it while he did like LS50 Meta. That is very odd and confusing.

I know quite few people and reviews who don't fully like the tonality of the R3 without EQ (same with the old LS50), the R3 has a bit of V-shaped estimated room response which is a bit recessed in the mid region:

Source: https://pierreaubert.github.io/spin...LS50+Meta&origin1=Vendors-QSC&speaker1=KEF+R3

Nothing that EQ cannot change, but often such small but wideband deviations can make a quite audible difference.

 

[truwarrior22]

Anyone able to compare the sound stage difference between the Revel M106 and LS50 Meta, I’ve heard both and like both, but listen to each in different rooms. Is the LS50 Meta the best if using a sub? While both sound great I feel the Meta comes away sounding more natural…? Just not sure regarding the overall sound stage difference between the two, ie does the Meta sound like a much smaller speaker, less scale?

 

[thewas]

Often loudspeakers with higher directivity (like for example the LS50 Meta compared to the M106) give the audible impression of a smaller but more precise sound stage, everything is a compromise and people should choose according to their personal needs and preferences.

 

[truwarrior22]

Often loudspeakers with higher directivity (like for example the LS50 Meta compared to the M106) give the audible impression of a smaller but more precise sound stage, everything is a compromise and people should choose according to their personal needs and preferences.

Thank you. Maybe LS50 Meta now then wait and see what the next gen M106 brings (whenever that maybe)….maybe they’ll use a similar woofer in the M126… LS50 Meta is a little cheaper too.

 

[Daka]

I think they will be used to a maximums of 1.5 meters

Then ls50 meta definitely. But as mentioned they need help and sound a class or two better with sun crossed at 80Hz

 

[Ciobi69]

Then ls50 meta definitely. But as mentioned they need help and sound a class or two better with sun crossed at 80Hz

Yes they will be crossed at 80hz and my surround amp is 200w at 8ohm Soo 0 problem in giving them power, i hope to find them used, i like the design a lot

 

[Burgunder]

Some even recommend crossing at 100 or 120Hz.

 

[pjn]

Absolutely incredible soundstage and dynamic range (particularly noticeable with a symphony orchestra) compared to an aging (and in need of a crossover rebuild) pair of Kef 104/2s. I am seriously astonished by the LS50meta crossed over at 80Hz to subs. To the extent that my center channel speaker (Focal Chora) is being replaced by an LS50meta also. Medium size room (15*15*8 with openings on 3 corners).