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KEF LS50 Meta Review (Speaker)

LeonidKogan

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I wonder if using high pass filter on those really makes a significant difference in clarity vs simply aligning the sub below LS50M extension? I've always loved those speakers, their imaging, accuracy, timbre etc., but since I bought Kali IN8 v2 I've had hard time justifying keeping LS50M. At higher SPL and full-range excerpts (Mahler's 2nd finale) they just sound compressed and muddy, while Kalis are much more effortless and clear. I have a small subwoofer but even with it they still don't sound as 'grand' as the Kalis. I only have RME ADI-2 so for now there is no way to use HPF on the KEFs. Will it make it as competent 3-way speaker as the Kalis?
 

Head_Unit

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I wonder if using high pass filter on those really makes a significant difference in clarity vs simply aligning the sub below LS50M extension?
Answer A: try it and let us know ;)
Answer B: LS50 has a small cone, so attempting to output any significant bass means a lot of excursion. That cone acts as a waveguide on the tweeter, therefore excursion modulates the treble response. A highpass filter would reduce that. How audible a difference? Try it and let us know ;);)
 

staticV3

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I wonder if using high pass filter on those really makes a significant difference in clarity vs simply aligning the sub below LS50M extension?
Here's the LS50M's multitone distortion full-range vs high-passed at 80Hz:

MTON Full.png MTON 80.png
Source: https://www.erinsaudiocorner.com/loudspeakers/kef_ls50_meta/

You can flip between them using the arrow keys to compare.

IMO, there's no significant improvement.
 

Paffi

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ehabheikal

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tlooo80 Hz is probably pretty low for this speaker - my crossover is at 140hz
my sub only goes to 120hz.
interestingly i had stupidly set the sub to also send lower frequencies to both speakers and sub. There was distortion in some tracks. When i set it up correctĺy it did not bottom out. Was it better above the bass i can not be certain
 

LeonidKogan

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Answer A: try it and let us know ;)
Answer B: LS50 has a small cone, so attempting to output any significant bass means a lot of excursion. That cone acts as a waveguide on the tweeter, therefore excursion modulates the treble response. A highpass filter would reduce that. How audible a difference? Try it and let us know ;);)
I've never ever seen my LS50's cones moving, I don't listen to electronic music with sub frequencies and also the only time I might go over 85dB peak is during orchestral culminations. That is still not enough to visibly move a cone. Probably it doesn't have any effect on directivity. I can't imagine how uncomfortably loud Amir must have pushed his speaker to separate the cone from the tweeter. Is that 'boxiness' I'm hearing on higher volumes an effect of distortion or something else? That I don't know.
@staticV3 damn that looks quite bad indeed. 80Hz crossover doesn't seem to go much and I do not intend to buy a second sub any time soon, and I'm not going to cross a single sub higher than that. Thanks.

Btw. Is there a way to add high-pass filter to the system while still keeping RME ADI-2 as a dac?
 

ViperDom

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I wonder if using high pass filter on those really makes a significant difference in clarity vs simply aligning the sub below LS50M extension? I've always loved those speakers, their imaging, accuracy, timbre etc., but since I bought Kali IN8 v2 I've had hard time justifying keeping LS50M. At higher SPL and full-range excerpts (Mahler's 2nd finale) they just sound compressed and muddy, while Kalis are much more effortless and clear. I have a small subwoofer but even with it they still don't sound as 'grand' as the Kalis. I only have RME ADI-2 so for now there is no way to use HPF on the KEFs. Will it make it as competent 3-way speaker as the Kalis?

I think it would be more productive for you to just post the frequency response of each setup. This would make it far easier to than attempting to decipher your personal adjectives.
At your listening volume chances are both setups could be set up & EQ'd to sound very similar.
I'd ditch the RME and replace with a MiniDSP so you can properly integrate the sub. Once you have the capability to fine tune alignment its an eye opener just how much it effects frequency response.
 

ViperDom

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Here's the LS50M's multitone distortion full-range vs high-passed at 80Hz:

View attachment 374476 View attachment 374477
Source: https://www.erinsaudiocorner.com/loudspeakers/kef_ls50_meta/

You can flip between them using the arrow keys to compare.

IMO, there's no significant improvement.

How is this test run? Is it a sweep? If yes, perhaps it is not measuring the distortion in question.
What i mean by this is that measuring the distortion at a discrete frequency is very different from measuring multiple. Like when a driver is producing components of both the bass line & vocals simultaneously.

This is something i had wandered reading past speaker test/reviews but never got around to asking, so i hope someone could explain in detail.
 

LeonidKogan

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I think it would be more productive for you to just post the frequency response of each setup. This would make it far easier to than attempting to decipher your personal adjectives.
At your listening volume chances are both setups could be set up & EQ'd to sound very similar.
I'd ditch the RME and replace with a MiniDSP so you can properly integrate the sub. Once you have the capability to fine tune alignment its an eye opener just how much it effects frequency response.
1718218595681.png

Green line is Kali eq'd to flat target without sub, orange line is LS50M+REL T/Zero. The 100Hz dip seen on the Kalis is a room mode (I just realized yesterday it improves significantly when I open the door of my big cloth wardrobe on the left LMAO), but the measurements were taken a few days ago. It is surprising to me that with LS50M the mode moves to 200hz.
 

staticV3

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How is this test run? Is it a sweep? If yes, perhaps it is not measuring the distortion in question.
A steady-state multitone signal is played on the speakers.

The sound is recorded, then analyzed.

The procedure is identical to multitone measurements of DACs and Amps.

For more details, there's a multitone distortion explainer video in the source I linked.
 

LeonidKogan

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1718310486873.png

@ViperDom I've installed LS50M today again and I've found the best setup so far - as long as graphs go. There's only one narrow dip and actually after this measurement I was able to slightly improve 410Hz, 850Hz and 6.5kHz. Of course they still have some limitations including distortion and SPL that Kalis are free of.
 
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