KEF LS60 Wireless Just Announced

[HarmonicTHD]

Support for a pc-based solution like Arc or Dirac (or several methods!) could make the LS60 (and the 50 wireless II) an incredible proposition.

Yes and it would be a pity if Kef would go the way of Genelc or Neumann and only offer a closed, proprietary room EQ system.

 

[BrokenEnglishGuy]

First, the mass I see on the KEF page for the LS50 Meta is 7.8 Kg.

Second, as I wrote above a 3-way crossover needs more components and especially inductors can be quite heavy.

Third, as I wrote you have to consider the size when comparing the masses, the total exterior volume of the LS50 enclosure is approximately 16.7 litres and of the R3 approximately 27.7 litres, so the masses per size 7.8/16.7=0.47 are 13.5/27.7=0.49 are very similar.

1 I aggre, I dont know where I saw the 7.2kg
5.7 KG of difference its correct

2. I aggre, but the extra crossover is not that heavy... 1.2kg for a driver and 1.8kg for the extra crossover parts? Hmm I dont think so

3. I aggre, but the layering/chamber/bracing is still a positive thing, maybe very necessary because of these 6.5" woofers, but a positive thing for the uniQ
The uniq shows better results with the chamber, thats why the new R series also have the chamber and the previous R series 2011 not
The previous R series have the Uniq similar to the ls50m, right to the port

To me, both cabinets are great enough

I dont imagine a real winner here, there is many thing that cant be quantify btw

 

[thewas]

To me, both cabinets are great enough

Yes, as written above all current better KEF series ones are exceptionally well engineered and not really any audible bottleneck.

 

[Mnyb]

That leaked image looks to have 6-6.5” woofers if the Uni-Q is the usual 5.25” (I believe all current Kef speakers are the same size). That would be the same size and number of drivers as the Blade Two. With active crossovers and DSP there’s no (engineering) reason why it can’t have an F3 <30Hz (the passive Blade Two is 33Hz with an F6 of 25Hz).

If that’s the case, and it has the same linearity and even dispersion as the other post-Meta Kef speakers, I can easily see this cannibalising their other products. The only way that wouldn’t happen is if it’s hamstrung in the SPL department or has a price approaching $10k. Imagine if it has built in room-correction - state of the art performance and all you need is a couple of electrical sockets and an internet connection.

I think , I migth be wrong that there is a large customer base that always prefere a passive speaker .
So even if the active offering gives the same sq for half the price it still doesn’t outcompetes the other speakers.

People that are into active speakers also expects more bang for the buck , ie a price effective solution and less bling

I think kef can serve both markets just fine .

Me , I don’t know what I want nowadays. I’m a big fan of active speakers ( and had them for a long time ), but reality migth make it so that my next pair is passive ? Or this ls60 migth be too tempting to pass ....

 

[killdozzer]

16.7 litres

How did you come by this number?

 

[Sancus]

You should offer an example of a significantly better LF performing 6 liter 2 way speaker to say that LF in LS50 is bad. I hope you see what I mean. One might say it's among the best LF 6 liter speaker outhere and one wouldn't be very wrong.

The dimensions of the LS50 are 30cm x 20cm x 28cm (rounding), which is 16.8L. The LS50's LF is not great. It's not ridiculously bad, but it's also not as good as you can get from a good 5" driver with no hole cut in it. The Genelec 8030C for example has much better distortion and better extension while being significantly smaller(10L).

This is, again, not news. All 2-way coaxials tend to be more limited than standard designs due to the compromises necessary to make a coaxial driver. That's why 3-ways are particularly valuable. They free the woofer from the constraints of having to fit in place and act as wave guide for the tweeter.

LS50 Meta 96dB, 8030C 96dB.

Spoiler

 

[E-Lint]

Oh the humanity....they've chopped off Gumby's arms and legs!

The image is still findable at Google. Just saw it.

 

[Vacceo]

Yes and it would be a pity if Kef would go the way of Genelc or Neumann and only offer a closed, proprietary room EQ system.

I´d rather like KEF concentrating their resources on refining their technologies (cabinets, uniq array, unicore, metamaterial, crossovers...) even further, than diverting them to room correction, which can be implemented quite well by a number of developers. I´d be super cool if they gave the user the chance to buy a Dirac/Audyssey/Arc/Lyngdorff/etc license and work from there.

 

[ROOSKIE]

The dimensions of the LS50 are 30cm x 20cm x 28cm (rounding), which is 16.8L. The LS50's LF is not great. It's not ridiculously bad, but it's also not as good as you can get from a good 5" driver with no hole cut in it. The Genelec 8030C for example has much better distortion and better extension while being significantly smaller(10L).

This is, again, not news. All 2-way coaxials tend to be more limited than standard designs due to the compromises necessary to make a coaxial driver. That's why 3-ways are particularly valuable. They free the woofer from the constraints of having to fit in place and act as wave guide for the tweeter.

LS50 Meta 96dB, 8030C 96dB.

Spoiler

View attachment 205908

HD isn't really the issue.
IMD and excursion limitations are the real (IMH somewhat competent hobbiest O) issues for which no real data is available.

I´d rather like KEF concentrating their resources on refining their technologies (cabinets, uniq array, unicore, metamaterial, crossovers...) even further, than diverting them to room correction, which can be implemented quite well by a number of developers. I´d be super cool if they gave the user the chance to buy a Dirac/Audyssey/Arc/Lyngdorff/etc license and work from there.

All of these companies still need to provide data that demonstrates their room correction improves sound above the bass region.
As of yet nothing. Just smoothed lines.

I use manual PEQ myself so that is what I'd like to see as an option. Something similar to the JBL 700p'series.

 

[thewas]

The dimensions of the LS50 are 30cm x 20cm x 28cm (rounding), which is 16.8L. The LS50's LF is not great. It's not ridiculously bad, but it's also not as good as you can get from a good 5" driver with no hole cut in it. The Genelec 8030C for example has much better distortion and better extension while being significantly smaller(10L).

Correct, although the deeper and more linear extension is also due to internal EQ on active loudspeakers which can be done externally though also on passive ones, on my desktop LS50 setup I use a HPQ filter which linearizes the bass response and additionally is a high pass filter to reduce distortion from bass lower than the reflex tuning similar to the one that many active loudspeakers have:

In the 80s and 90s quite many loudspeaker brands offered similar filters to use between the pre-amp and amp or the tape recorder loop.

 

[Vacceo]

Do they reproduce 20hz at audible levels? Holy shit!

 

[thewas]

Do they reproduce 20hz at audible levels? Holy shit!

Not really, as you can see at 20 Hz they have dropped already more than 40 dB at those ASR Klippel NFS measurements, mind you thank you to this EQ and room gain with close boundaries they get down linearly to approximately 40 Hz at my listening position which is quite good for their size and sufficient for most of the music I listen to:

 

[Sancus]

HD isn't really the issue.
IMD and excursion limitations are the real (IMH somewhat competent hobbiest O) issues for which no real data is available.

Sure but the very large HD difference is a perfectly reasonable proxy for those things for this purpose so it doesn't actually matter.

Correct, although the deeper and more linear extension is also due to internal EQ on active loudspeakers which can be done externally though also on passive ones

Yes of course, though the LS50 is already over 100% THD at 50hz and 80dB, the 8030C doesn't even get to 100% at 96dB. So there is a large difference in bass performance. That is the main thing I was illustrating.

 

[Vacceo]

Not really, as you can see at 20 Hz they have dropped already more than 40 dB at those ASR Klippel NFS measurements, mind you thank you to this EQ and room gain with close boundaries they get down linearly to approximately 40 Hz at my listening position which is quite good for their size and sufficient for most of the music I listen to:

View attachment 205943

Audible at very close distance, so that means it still shows up in the graphic even if the response is very, very low...

 

[ROOSKIE]

Sure but the very large HD difference is a perfectly reasonable proxy for those things for this purpose so it doesn't actually matter.

I don't agree that HD is much of a proxy for IMD or excursion limits.
Some drivers have HD at levels where they would not be suffering from other issues.
Other may have lowish HD levels right up to near XMAX.
Picture a paper cone 15" driver that has 10% HD distortion at 100hrz at 96db yet is only moving 1mm of it's 8mm XMAX and another that also has 10% HD distortion yet is moving 2mm of 3mm XMAX.

Now a high end 6" driver with 10% HD @100hrz distortion moving 10mm of 12mm XMAX - so you likely have doplar distortion from the airspace in front of the frantically excurting driver. Now ask that driver to hit an additional 40hrz peak and play the entire midrange cleanly.

Now a Compression tweeter loaded in a waveguide or horn. It has 4% HD at 2krz yet can play that frequency at 128db. Compared then with a high end dome tweeter that has 0.3% HD at 2krz at 96db yet exceeds XMAX at 105db @2khz.

The list goes on. HD is not IMD nor is it Apples to Apples, nor is it a great indicator of driver limits. At least in terms of what I have be exposed to thus far.

A driver with 50% HD but is 10db down may be inaudible at 50hrz and yet another may sound horrid as it is at peak output there and is spewing audible junk.

Or distortion that is not from the driver reaching any limit but rather crossover/inductor components or edge diffraction (which as I understand it is a common source of compression driver measured HD)

Sorry but as of now, I just don't agree on HD being useful as anything more than a test of HD.

This is on of the major reasons for Amir to listen and listen loudly at times.

 

[Sancus]

I don't agree that HD is much of a proxy for IMD or excursion limits.

We'll just have to agree to disagree, then. To me it's very clear and obvious that if one woofer has >100% THD at 80dB in bass, and another has significantly less at 96dB, +16dB(!) louder, then the second one is more capable and that's the end of the story. Talking about distortion factors for which we have no data or understanding at all defeats the entire point!! I was showing with data which is more capable, lol.

As far as IMD goes, I agree there is anecdotal evidence it's a problem with 2-way coaxials. But I've never seen any good research on how to measure, let alone interpret IMD. Somebody's going to say "it's just a multi-tone test!" -- sure, what frequencies, how many, what conditions for pass/fail/audibility? Everybody has a different take on it, some of which are not even internally consistent...

Somebody in the LS50 Meta thread pointed out that the static center section of the wave guide is actually pretty deep, and while this has the cost of an even larger woofer cutout, it's possible that it mitigates the IMD. It may very well be that Kef knows all this and deliberately calculated the tradeoff there so that IMD/geometric/doppler/whatever distortion is never going to be the most audible problem with the LS50.

 

[Axo1989]

Yes of course, though the LS50 is already over 100% THD at 50hz and 80dB, the 8030C doesn't even get to 100% at 96dB. So there is a large difference in bass performance. That is the main thing I was illustrating.

Declaring % harmonic distortion at low frequencies, below the speaker's output range isn't very meaningful: as speaker output drops, % distortion is higher as a ratio, but not in dB (meaning the amplitude of the harmonic, not the ratio of that to the fundamental signal).

Also, to be pedantic, 2nd harmonic distortion of (say) a 50 Hz fundamental actually sounds at 100 Hz (and so on, for higher harmonics) but isn't graphed that way. A speaker that barely produces sound at 25 Hz doesn't magically produce 'distortion' at that frequency, the distortion sounds at the harmonic multiples (so the KEF doesn't actually emit 85 dB sound at 25 Hz, per the graph). I'm not saying anything you don't know, I expect.

Your overall point that the Genelec produces less distortion at higher levels than the KEF is valid though.

 

[Darvis]

I have 7 LS50 Metas here, with a KF92 sub. Optimising for multichannel music, so I want all my speakers the same - I've got a sort of thing about refusing to have better fronts on principle.

And when buying 7 of a speaker (and potentially stands), rather than 2, you become more price sensitive. Can't afford much more than the LS50. R3 on sale, possibly, but not more than that.

Considered the R3, but the LS50 Meta won on a few grounds.

1) Cosmetics
2) Matching stand with bolts
3) Size
4) It functions as a matching centre and fits where I need it
5) Price

Did you easily find a dealer accepting to sell an odd number?

 

[KMO]

Did you easily find a dealer accepting to sell an odd number?

Only in plainer colours. I wanted the blue, and he wouldn't do it for them. So I have a spare stored safely away for when something unpleasant happens to one of the 7. At least got a fair bit off RRP for the number I was buying.

And having the spare already turned out to be handy when one of the set was faulty (crossover fault, causing about 2% distortion in the midrange, but no appreciable frequency response error). Saved me being short a speaker for the few weeks it took to get a replacement.

This was in Europe, mind - KEF's US store will sell you individual ones:

LS50 Meta Center Channel | KEF

Single Center Channel Speaker LS50 Meta is a highly precise, emotionally engaging loudspeaker built on revolutionary acoustic technology. Designed around the Uni-Q 12th Generation with Metamaterial Absorption Technology (MAT) driver array, this solid, compact loudspeaker is capable of delivering...

www.shop.us.kef.com

Although it's listed as a "center", it's not any different, just an unpacked one from a pair. No modified trim ring to get the text the right way up when sideways. (You can take it off and put it back yourself, but it can only be rotated in 60 degree steps, annoyingly).

 

[sifi36]

There’s a Belgian(?) video unboxing and review on YouTube that’s gone live. No spec sheet and I don’t understand whatever language it is. Any members able to glean any information from it?