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KEF LS50W II measurements

Nuyes

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This is a KEF LS50W II.


Very surprising speaker with near zero hiss noise despite being an active speaker.





00.jpg














FR/SPL





01.png









The bass extension is 44.9hz(-6dB).





Overall, the balance is excellent, except for 1k to 2k.

















Directivity





02.png
03.png
04.png
05.png















As expected of a coaxial speaker... It's really smooth, horizontal or vertical.





It's amazing that there's nothing that stands out, and it's pretty much the same orientation from about 2khz to the next.

















Beamwidth





06.png
07.png









Likewise, it's a beautiful figure that doesn't deviate much from about 50 degrees and stays uniform.

















Polar plot



08.png
09.png









Horizontal and vertical data almost overlap for most angles on the front.





It's also a great directional control.




















THD





10.png
11.png
12.png
13.png









The approximately 100hz is due to the measured space and dip, so you should ignore it.











In 95dB SPL, over 200hz, well over 1.5%. It's a bit disappointing.





It clearly shows that the device is not suitable for playback at a high volume.

















Multitone test





14.png
15.png









A distortion has appeared that remains at a maximum level of -20 dB.





This is about 10% when converted to %.














If it is a well-made speaker, I think it should be maintained at a level that does not exceed -30 to 35 dB in all bands.























Also, considering the use of the subwoofer, I put restrictions on the signal below 80hz and measured it again.(This measurement is inspired by Erin.)








16.png






It's a little bit less, but it's the same tendency.




















And I overlapped these two data.





17.png









Given the constant decrease in distortion overall, it is expected that the displacement of the woofer for low regeneration will be the most significant.











And a reduction in distortion between 100 and 200 Hz is noticeable.




















18.png
19.png









I measured it by increasing the output by 10 dB SPL.











Given that distortion increases in proportion to the output, this is thought to be a characteristic of this speaker, not a other factor.














Compression test











20.png









When the output was increased to 96 dB SPL, it was found that the same level of compression was applied very strongly across the entire.





This is not the characteristic of the speaker driver itself, but rather a limiter is expected to hang inside the amplifier.





(Compression cannot be this uniform with the characteristics of the driver itself.)











Anyway, it's never an advantage for loud volume playback, and when there are instantaneous peak signals in content such as movies, it seems likely that they will not be expressed dynamically relative to their intentions.























And finally, the measured FR/SPL





I took Erin's data and KEF official data and conducted cross-validation.








21.png









First is the comparison between Erin and my data.











With the exception of the LF roll-off point and some ultra-high bandwidth, the positions of the balance and various dips tend to match.








22.png









Comparison with KEF official data.





No dips was found between 1khz and 2khz.





With the exception of a weak dip of 10 kHz, the balance seems very good.











23.png






Finally, I compared the three data at once.











The KEF data, which conducted cross-validation with the two reviewer data, showed a clear difference of 1 khz and 2 khz.





The analysis of this is at your disposal.























I am not a native English speaker, and I rely mostly on translators.


Therefore, my personal evaluation of the product may cause you more misunderstanding than necessary, and I am concerned about this.





Therefore, I will put my personal assessment on hold.


So, what's your opinions?
 

Absolute

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Wow, this is quite the effort you have gone through. Impressive!

Looks excellent, this. But there's two things that catches my eye; As with all small speakers, there's a huge discrepancy in directivity where you go from around 80 degrees to 50 degrees dispersion from ~2 khz to ~4 khz. Quite a jump in the most sensitive area of our ears.

Also, if the multi-tone distortion is accurate it really shows the drawback of going small.
 

Soniclife

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The full range vs 'with sub' multi-tone distortion test was very interesting, thanks.
Agreed. I'd to see this measurement done at a frequency that simulates how the driver would behave if it was a three way speaker. I'm aware the driver is different in Kef 3 way speakers, but it would still be interesting.
 

Vacceo

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The discontinuity between 1K and 2K hz should be relatively easy to correct, same for the dips around 8k hz. Another reason to ask KEF for Dirac/Audyssey/... room eq compatibility. I´m aware it can be done with an equalized external source, but that would only apply to said source.
 

Tangband

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This is a KEF LS50W II.


Very surprising speaker with near zero hiss noise despite being an active speaker.





View attachment 227742













FR/SPL





View attachment 227743








The bass extension is 44.9hz(-6dB).





Overall, the balance is excellent, except for 1k to 2k.

















Directivity





View attachment 227744View attachment 227745View attachment 227746View attachment 227747














As expected of a coaxial speaker... It's really smooth, horizontal or vertical.





It's amazing that there's nothing that stands out, and it's pretty much the same orientation from about 2khz to the next.

















Beamwidth





View attachment 227748View attachment 227749








Likewise, it's a beautiful figure that doesn't deviate much from about 50 degrees and stays uniform.

















Polar plot



View attachment 227750View attachment 227751








Horizontal and vertical data almost overlap for most angles on the front.





It's also a great directional control.




















THD





View attachment 227752View attachment 227753View attachment 227754View attachment 227755








The approximately 100hz is due to the measured space and dip, so you should ignore it.











In 95dB SPL, over 200hz, well over 1.5%. It's a bit disappointing.





It clearly shows that the device is not suitable for playback at a high volume.

















Multitone test





View attachment 227756View attachment 227757








A distortion has appeared that remains at a maximum level of -20 dB.





This is about 10% when converted to %.














If it is a well-made speaker, I think it should be maintained at a level that does not exceed -30 to 35 dB in all bands.























Also, considering the use of the subwoofer, I put restrictions on the signal below 80hz and measured it again.(This measurement is inspired by Erin.)








View attachment 227758





It's a little bit less, but it's the same tendency.




















And I overlapped these two data.





View attachment 227759








Given the constant decrease in distortion overall, it is expected that the displacement of the woofer for low regeneration will be the most significant.











And a reduction in distortion between 100 and 200 Hz is noticeable.




















View attachment 227760View attachment 227761








I measured it by increasing the output by 10 dB SPL.











Given that distortion increases in proportion to the output, this is thought to be a characteristic of this speaker, not a other factor.














Compression test











View attachment 227762








When the output was increased to 96 dB SPL, it was found that the same level of compression was applied very strongly across the entire.





This is not the characteristic of the speaker driver itself, but rather a limiter is expected to hang inside the amplifier.





(Compression cannot be this uniform with the characteristics of the driver itself.)











Anyway, it's never an advantage for loud volume playback, and when there are instantaneous peak signals in content such as movies, it seems likely that they will not be expressed dynamically relative to their intentions.























And finally, the measured FR/SPL





I took Erin's data and KEF official data and conducted cross-validation.








View attachment 227763








First is the comparison between Erin and my data.











With the exception of the LF roll-off point and some ultra-high bandwidth, the positions of the balance and various dips tend to match.








View attachment 227764








Comparison with KEF official data.





No dips was found between 1khz and 2khz.





With the exception of a weak dip of 10 kHz, the balance seems very good.











View attachment 227765





Finally, I compared the three data at once.











The KEF data, which conducted cross-validation with the two reviewer data, showed a clear difference of 1 khz and 2 khz.





The analysis of this is at your disposal.























I am not a native English speaker, and I rely mostly on translators.


Therefore, my personal evaluation of the product may cause you more misunderstanding than necessary, and I am concerned about this.





Therefore, I will put my personal assessment on hold.


So, what's your opinions?
Very interesting - This loudspeaker sound as good as the measurements show. Much better than the passive ls50. I really liked listening to this speaker in the store , and I thought it sounded way better than the Kef ls50 Meta. The sound clarity from this speaker was on pair with the Genelec 8340 I would say, but with slightly worse sounding bass. This speaker seems very linear but unsuitable to be used without a subwoofer . The MD distortion with and without 80 Hz crossover says it all.

B99AD403-C2A6-40F0-9B69-E661F3911D91.png
 
Last edited:

Vacceo

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When used with the KC62, the APP sets the high pass on the subwoofer at 70hz and the low pass at 45hz. Data looks quite coincident on those areas.
 

Tangband

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Its a bit disappointing to see the multitone measurements that shows about 10 % distortion ! ( -20 dB ) when playing many tones at the same time with 85 dB spl.

The future of high end hifi points at multidrivers with many crossoverpoints , ie 4 or 5 way speakers with dsp crossover.
This probably gonna lead to much lower distortion in MD measurements and the soundquality will be better with real music.
7945E666-8873-46E4-BCA2-662B9CE72FD2.png
031235FC-BB6A-4A42-8DA5-2FA49223479F.png
 
Last edited:

Ata

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Big thanks to @Nuyes for the detailed measurements?

I do have a question. This is the first time I come across multi-tone test and multi-tone distortion graphs for a speaker (as opposed to an electronic component, such as a DAC or AMP). Is this common, I don't see it in other measurements on this site, including Amir's?

Is such a multi-tone test correlatable to the human perception of how good a speaker is?
 
OP
Nuyes

Nuyes

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Big thanks to @Nuyes for the detailed measurements?

I do have a question. This is the first time I come across multi-tone test and multi-tone distortion graphs for a speaker (as opposed to an electronic component, such as a DAC or AMP). Is this common, I don't see it in other measurements on this site, including Amir's?

Is such a multi-tone test correlatable to the human perception of how good a speaker is?
Multi-tone distortion represents the sum of the noise and all distortion in the loudspeaker measurement environment.

I can't say that this directly represents the performance of the loudspeaker.
In addition, even if the same level of distortion appears, there may be differences in hearing depending on the cause.

However, it is certain that the lower it is, the better.
 

Tangband

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Multi-tone distortion represents the sum of the noise and all distortion in the loudspeaker measurement environment.

I can't say that this directly represents the performance of the loudspeaker.
In addition, even if the same level of distortion appears, there may be differences in hearing depending on the cause.

However, it is certain that the lower it is, the better.
10 % multitone distortion is a very high value If we compare with traditional harmonic distortion measurements thats often less than 1 % at 85 dB.
With that said- 85 dB is rather loud and with two loudspeakers its almost 90 dB , and with roomgain 5-10 dB more in the bass.

Multitone distortion measurements mirrors the way real music is - many tones played at the same time.

Instead of using one single driver, one can use 4 with different crossoverpoints. With this approach, it doesnt matter If the bassplay and bassdrumming are at high spl - the other three drivers will be unaffected of the high volume in the bass and the multitone distortion can be lower than 1 % .

This is Kali , an threeway active nonexpensive loudspeaker . It measures rather good in multitone distortion , because its an active speaker with many amplifier thats independent from eachother, and its a threeway speaker with many crossover points. The measurements are done by Nuyes.

085BA1AD-4EAE-4555-A37D-5390E650BD0B.png
 
Last edited:

okok

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This is Kali , an threeway active nonexpensive loudspeaker . It measures rather good

this kali you mentioned and admired had been measured by OP and got bad design

we know Tangband is maker of speaker driver, but driver alone ain't the whole speaker
 

aarons915

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I can't help but notice the region of "roughness" around 1-3Khz is also the area with high IMD distortion. Maybe there is another explanation but it is interesting
 
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