KEF LS50 disappointment :(

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Freddy58

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jackocleebrown said:
Dear hg,

Thanks for your curiosity. You'll note that I specifically said "believe I have heard a difference" I'm not ruling out expectation bias, or even perhaps some dodgy equipment. I've not done any specific study and certainly not any AB (or any other kind of statistically significant) testing. Shkumar asked for my personal experiences, which is what I gave.

Kind regards, Jack.

Always a dangerous thing to do, on here *biggrin*
 

Gazzip

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How can ANYBODY seriously suggest that all integrated amplifiers sound the same?! The pre-amp stages are generally voiced to produce a given manufacturer's house sound for christ's sake! Use your ears! I weep.....
 

Vladimir

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jackocleebrown said:
Vladimir, you're right that in a sense the Uni-Q drivers are a contiunous lineage right from the early ones of the Jones/Fincham era. However, I would also point out that at several points we went back to the drawing board and designed a new "platform" from scratch. The current Uni-Q "platform" was developed from scratch in around 2009/2010 following the Concept Blade project.

Also wanted to mention that the R500/700/900 Uni-Q is a little different from the LS50/R100 because the cone driver is optimised for MF only; the excursion requirement is much lower and this allows the surround and motor to be optimised for better midrange performance.

Kind regards, Jack.

Just expressing my opinion that KEF is a very consistent evolutionary engineering company. There is lineage in driver technology development, there are families (generation) of drivers and there are design milestones. The KEF LS50 is an island but as a member of a greater archipelagos, and it has its strengths and weaknesses as any standmount speaker. The LS50 created such a hype as if it is a one off innovation by KEF developed on its own merits. Despite everyones enthusiasm, sorry to say, the LS50 is not revolutionary but evolutionary engineering product and the laws of physics mercilessly apply to it.
 

jackocleebrown

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Vladimir said:
Just expressing my opinion that KEF is a very consistent evolutionary engineering company. There is lineage in driver technology development, there are families (generation) of drivers and there are design milestones. The KEF LS50 is an island but as a member of a greater archipelagos, and it has its strengths and weaknesses as any standmount speaker. The LS50 created such a hype as if it is a one off innovation by KEF developed on its own merits. Despite everyones enthusiasm, sorry to say, the LS50 is not revolutionary but evolutionary engineering product and the laws of physics mercilessly apply to it.

Yes, I agree completely. I did not mean to contradict you, only to clarify that the Uni-Qs of today have evolved quite a lot compared to the first.

Kind regards, Jack.
 

Freddy58

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Vladimir said:
Gazzip said:
The ABX testing refered to here applies to power amplification stages. Think of pre amplification as malt whiskey and power amplification as pure water. As long as it is pure the water will taste the same wherever it comes from. However adding different malts from different distilleries will dramatically alter the flavour of the resulting drink.

Actually, if the manufacturer hasn't tampered with the preamp intentionally, it should have no sonic character and it is a pretty simple gain stage with small power requirements.

On the other hand the power amp requires a lot of power because speakers are essentially a short circuit like an electric heater. Everytime the speaker resistance (impedance) drops, we are getting closer to absolute dead short of 0 ohms. The amplifier needs to have large power reserves (very good PSU) and always deliver sufficient current so the voltage rails wont sag. If the voltage rails sag, the amplifier no longer maintains a flat frequency response (nondeviated original signal) and starts changing the sonic character and if pushed further, it enters clipping.

The best amplifier is a wire with a volume knob. This is only possible with amplifiers ignorant of loudspeaker impedance changes and the perfect amplifier is an endless reserve of power and nothing else. It's not a musical instrument. However, some like flavored water and some like it pure. Everyone has the freedom of spending their money any way they prefer.

Your Brystons and the Electrocompaniet Nemos are well regarded as 'can't be bothered' with what speakers they drive.

Nicely put Vlad
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Vladimir

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Gazzip said:
The ABX testing refered to here applies to power amplification stages. Think of pre amplification as malt whiskey and power amplification as pure water. As long as it is pure the water will taste the same wherever it comes from. However adding different malts from different distilleries will dramatically alter the flavour of the resulting drink.

Actually, if the manufacturer hasn't tampered with the preamp intentionally, it should have no sonic character and it is a pretty simple gain stage with small power requirements.

On the other hand the power amp requires a lot of power because speakers are essentially a short circuit like an electric heater. Everytime the speaker resistance (impedance) drops, we are getting closer to absolute dead short of 0 ohms. The amplifier needs to have large power reserves (very good PSU) and always deliver sufficient current so the voltage rails wont sag. If the voltage rails sag, the amplifier no longer maintains a flat frequency response (nondeviated original signal) and starts changing the sonic character and if pushed further, it enters clipping.

The best amplifier is a wire with a volume knob. This is only possible with amplifiers ignorant of loudspeaker impedance changes and the perfect amplifier is an endless reserve of power and nothing else. It's not a musical instrument. However, some like flavored water and some like it pure. Everyone has the freedom of spending their money any way they prefer.

Your Brystons and the Electrocompaniet Nemos are well regarded as 'can't be bothered with' what speakers they drive.
 

unsleepable

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jackocleebrown said:
Just wanted to say, yes this is correct - I think the quote above was something I posted on another forum (quite a while ago now) when asked a similar question.

Vladimir, you're right that in a sense the Uni-Q drivers are a contiunous lineage right from the early ones of the Jones/Fincham era. However, I would also point out that at several points we went back to the drawing board and designed a new "platform" from scratch. The current Uni-Q "platform" was developed from scratch in around 2009/2010 following the Concept Blade project.

Also wanted to mention that the R500/700/900 Uni-Q is a little different from the LS50/R100 because the cone driver is optimised for MF only; the excursion requirement is much lower and this allows the surround and motor to be optimised for better midrange performance.

Kind regards, Jack.

Ey Jack, I am very much enjoying your input in this thread. Thank you for that.

You forgot to mention the R300. Is the Uni-Q in the R300 optimised in the same manner as in the R500 and larger speakers, or is it more like the one in the R100? I would assume the former. I am contemplating an upgrade, and for the moment the R300 and R500 are two big contenders—but I am very much into standmounters. Thanks.
 

hg

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jackocleebrown said:
Thanks for your curiosity. You'll note that I specifically said "believe I have heard a difference" I'm not ruling out expectation bias, or even perhaps some dodgy equipment. I've not done any specific study and certainly not any AB (or any other kind of statistically significant) testing. Shkumar asked for my personal experiences, which is what I gave.

Yes I was aware of what you said and why but I am also aware of how the original was likely to be read by Shkumar and many of the posters here. Whatever, we all have to make our way in the real world and it seemed a curious choice rather than a poor one.
 

jackocleebrown

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unsleepable said:
Ey Jack, I am very much enjoying your input in this thread. Thank you for that.

You forgot to mention the R300. Is the Uni-Q in the R300 optimised in the same manner as in the R500 and larger speakers, or is it more like the one in the R100? I would assume the former. I am contemplating an upgrade, and for the moment the R300 and R500 are two big contenders—but I am very much into standmounters. Thanks.

Thanks!

Whoops, I forgot the R300 - it is the same Uni-Q as the R500/R700/R900.

Kind regards, Jack.
 

Vladimir

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Gazzip said:
As a matter of fact there is a story floating around in the ether that PMC almost took Kef to court over some of the marketing photography they used for the LS50. Something to do with Metropolis studios being used for the Kef photo shoot (mixing desk in a darkened room with a sound engineer intently listening to a pair of LS50's) and PMC's kit being photoshopped out of the image backgrounds. Could be total poop of course but the story is out there having heard it from several sources.....*bomb*

news.2008-office-v2.jpg
 

shkumar4963

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Quote from another publication:

You make good points in this, but I can't address them because I don't have the technical insight into the designs. So I did as you suggested and sent your questions to KEF's Johan Coorg and this is what he said:

It may be of use to go into a little more depth about our Uni-Q development:

The drivers from the Q series, R series and LS50 all share a common lineage. The Q-series speakers were the first to be developed around 2010 as a concerted effort to get some of the features of the Concept Blade drivers into "affordable" loudspeakers. Over the years following the launch of the current Q range, we have refined and tweaked the drivers, resulting in those used in the R-series and LS50 drivers.

A quick summary: There are 5.25”, 6.5”, and 8” Uni-Q driver arrays in the Q range. The driver in the two-way R100 is based on the Q100 driver, but has a different cone (which you can identify the driver by from the font) and some tweaks to the tweeter and midrange magnet systems to reduce the distortion (addition of shorting rings and a copper cap).

The LS50 driver is a special edition of the R100 driver with a different voice-coil spec (to give a slightly different bass response in the system). The surround is also different and gives a slightly tidier upper mid-frequency response. We slightly adjusted the geometry around the tweeter-magnet outside diameter, also to improve the mid-frequency response.

The R-series Uni-Q as used in R300, R500, R700, and R900 is better than the LS50 one. The tweeter is the same as the LS50 tweeter. The small surround on the R-series mid-frequency driver greatly improves the response of the midrange and also improves the tweeter response as it presents smaller "disturbance" in the waveguide.

As ever with loudspeakers, people have different tastes -- we have come across many who love the LS50 (79Hz, +/-3dB), but require more bass and scale. They often choose the R300 (50Hz, +/-3dB) or R500 (46Hz, +/-3dB). Some others, albeit fewer people, go for combining the LS50 with a subwoofer. But most appreciate the raison d'être of the LS50 as a purist point-source monitor, and, given the right acoustics and positioning and driven by quality electronics, are more than happy with the bass extension.

KEF's fundamental approach is to try to offer differing designs with engineering trickled down as far as possible from the very best, to suit varying tastes, but trying also to maintain a "family sound."

Johan Coorg
KEF
 

Gazzip

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Freddy58 said:
Vladimir said:
Gazzip said:
The ABX testing refered to here applies to power amplification stages. Think of pre amplification as malt whiskey and power amplification as pure water. As long as it is pure the water will taste the same wherever it comes from. However adding different malts from different distilleries will dramatically alter the flavour of the resulting drink.

Actually, if the manufacturer hasn't tampered with the preamp intentionally, it should have no sonic character and it is a pretty simple gain stage with small power requirements.

On the other hand the power amp requires a lot of power because speakers are essentially a short circuit like an electric heater. Everytime the speaker resistance (impedance) drops, we are getting closer to absolute dead short of 0 ohms. The amplifier needs to have large power reserves (very good PSU) and always deliver sufficient current so the voltage rails wont sag. If the voltage rails sag, the amplifier no longer maintains a flat frequency response (nondeviated original signal) and starts changing the sonic character and if pushed further, it enters clipping.

The best amplifier is a wire with a volume knob. This is only possible with amplifiers ignorant of loudspeaker impedance changes and the perfect amplifier is an endless reserve of power and nothing else. It's not a musical instrument. However, some like flavored water and some like it pure. Everyone has the freedom of spending their money any way they prefer.

Your Brystons and the Electrocompaniet Nemos are well regarded as 'can't be bothered' with what speakers they drive.

Nicely put Vlad

I am pretty sure we are saying the same thing. All malt whiskey is made from the same stuff and left alone it would all taste exactly the same at the end of the process. It is not however left alone. The distilleries put their "house taste" on to it by peating the malted barley for varying lengths of time, or not as the case may be, and ageing their young whiskey in different barrel types. Rightly so too as some like it peaty and salty whereas others like it smooth and sweet. A pretty neat analogy for HiFi pre-amp manufacture and the introduction of a "house sound" I thought?

Your description of how a power amp can change the sound may be technically correct but it is not appropriate in disproving/challenging the ABX testing suggesting that all power amps sound the same. I suspect that the amplifier circuits would have to be well implemented and running correctly within their capability during any ABX testing to make it a true A-B test. I don't dispute that an amp pushed to the edge and beyond in to clipping will change the sonic signature, although I concede I have never done that myself. However your example is like boiling the pure water for one drink and adding ice to the other in my whiskey analogy. Not a fair test.
 

shkumar4963

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But I feel that LS50 box is better constructed than R300 box. And so even though 3 way design in R300 is better optimized for all frequencies and a separate 6 inch woofer helps, a less stiff box design in R300 colors the sound that is not in LS50. Now some people like that coloration. They call it "Musical" while others like a more clinical "pure" sound of ls50.

There may be other reasons for "Musical" nature of R300 sound. Of course, only Jack can tell if that is how they were both designed and if the sound signature difference was intentional or just an outcome of limited funds available to manufacture a stiffer box for R300. Since R300 has two separate drivers, there may have been less funds left to build a better box and still stay within the market price target.

Jack please comment if it is not a controversial topic.
 

Native_bon

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David@FrankHarvey said:
Native_bon said:
NOPE. For example, If 70% of people dislike the sound of the LS50 as suppose to 30% who is in the majority?
I don't see what majorities have to do with speaker quality.
How can you qoute just part of my post.. Why not the whole content..? Thats a sign of playing dirty dnt you think. Again if 70% of people dnt like the sound of any speaker, it matters not if stereophile likes it or not. People from stereophile are humans like any other person. Stereophile has its own opinion. Stereophile saying its a superior speaker as you say, does not mean people will then automatically like the sound of the LS50's
 

shkumar4963

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shkumar4963 said:
So let's see how many would like CM5 or CM1 or 685s2 compared with LS50 for their main speakers.

They are similarly priced and of similar size.

Let's here from all of yoy not based on theory but based real side by side audition.
 

Frank Harvey

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Native_bon said:
How can you qoute just part of my post..
Easy.

Why not the whole content..?
Because I was answering that section of your post. Being precise, keeping it simple.

Thats a sign of playing dirty dnt you think.
What?!!!

Again if 70% of people dnt like the sound of any speaker, it matters not if stereophile likes it or not. People from stereophile are humans like any other person. Stereophile has its own opinion. Stereophile saying its a superior speaker as you say, does not mean people will then automatically like the sound of the LS50's
Agreed. But how many people do or don't like a speaker is irrelevant.
 

Native_bon

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David@FrankHarvey said:
Native_bon said:
How can you qoute just part of my post..
Easy.

Why not the whole content..?
Because I was answering that section of your post. Being precise, keeping it simple.

Thats a sign of playing dirty dnt you think.
What?!!!

Again if 70% of people dnt like the sound of any speaker, it matters not if stereophile likes it or not. People from stereophile are humans like any other person. Stereophile has its own opinion. Stereophile saying its a superior speaker as you say, does not mean people will then automatically like the sound of the LS50's
Agreed. But how many people do or don't like a speaker is irrelevant.
Oh yes it is, cause if people dnt like it no sales, as a result the company makes no money.
lightbulb.gif
 

shkumar4963

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Quote:
Again if 70% of people dnt like the sound of any speaker, it matters not if stereophile likes it or not. People from stereophile are humans like any other person. Stereophile has its own opinion. Stereophile saying its a superior speaker as you say, does not mean people will then automatically like the sound of the LS50's

End of Quote

That is fine if Stereophile actually felt that LS50 were Class A speakers. What I want to make sure that it was not part of a KEF funded marketing campaign.

I hope not.
 

BigH

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shkumar4963 said:
Quote: Again if 70% of people dnt like the sound of any speaker, it matters not if stereophile likes it or not. People from stereophile are humans like any other person. Stereophile has its own opinion. Stereophile saying its a superior speaker as you say, does not mean people will then automatically like the sound of the LS50's

End of Quote

That is fine if Stereophile actually felt that LS50 were Class A speakers. What I want to make sure that it was not part of a KEF funded marketing campaign.

I hope not.

Stereophile love British speakers. How many bad reviews do you see in stereophile?
 

Frank Harvey

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Native_bon said:
Oh yes it is, cause if people dnt like it no sales, as a result the company makes no money.
30% is still rather a large population. And I'm sure KEF would have done their homework before even beginning to design such a speaker (or indeed any product). I believe KEF have sold more LS50s than they predicted, so it doesn't really matter how many people don't like them, which may be why they have continued to produce them after the initial "anniversary" run. Plus, if they weren't liked that much, I doubt producing them in white would be a good business plan...
 

CnoEvil

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Freddy58 said:
Oh for goodness sake! If you like them, buy them. If not, don't.

That's far too sensible and would have stopped this thread 900 posts ago...so a real killjoy attitude.

If you want to know how bad the LS50s are, listen to somebody who hasn't lived with them...or better still, somebody who hasn't heard them. *scratch_one-s_head*
 

Freddy58

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CnoEvil said:
Freddy58 said:
Oh for goodness sake! If you like them, buy them. If not, don't.

That's far too sensible and would have stopped this thread 900 posts ago...so a real killjoy attitude.

If you want to know how bad the LS50s are, listen to somebody who hasn't lived with them...or better still, somebody who hasn't heard them. *scratch_one-s_head*

thumbs_up.gif
*biggrin*
 
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