KEF R100 speaker review

[Andy Clough]

I know a lot of you have been keen to hear what we think of the KEF R Series, so in case you missed this month's issue of the mag, here's the link to the full review of the KEF R100. Clickety

 

[MUSICRAFT]

Hi Andy

Thanks.

All the best

Rick @ Musicraft

 

[Anonymous]

I know a lot of you have been keen to hear what we think of the KEF R Series, so in case you missed this month's issue of the mag, here's the link to the full review of the KEF R100. Clickety

Thanks andy, this is a very accurate and detailed review of the R100's and the WHF Team should be congratulated on this review.

one thing i would point out when the reviewers mention "There is a slight trade-off: with some tracks, bass notes can sound just a touch overblown" I did find that the case when they were relativly new but after 4-6 weeks this will dissapear..

 

[nopiano]

Funnily enough I must have spotted the review around the same time you posted this thread, Andy.

I'm curious about the relationship between this R100 and the LS50 which seems to share the driver (though a different colour!) and different cabinet appearance. If anyone can highlight the main differences - in sound rather than looks - that would be great.

 

[Andy Clough]

We haven't heard the LS50s yet, but I'm told they are inbound for a review in the next month or two.

 

[nopiano]

We haven't heard the LS50s yet, but I'm told they are inbound for a review in the next month or two.

Great, thanks, Andy. I'll look out for that, and maybe seek out a pair to hear too. Impatient!

 

[Frank Harvey]

I'm curious about the relationship between this R100 and the LS50 which seems to share the driver (though a different colour!) and different cabinet appearance. If anyone can highlight the main differences - in sound rather than looks - that would be great.

While they share similarities, they do sound quite different. The biggest difference is the cabinet and reflex port. I believe the engineers were given a free reign to make the best possible cabinet they could in order for the driver to work at its best without interference from the cabinet, which would usually be the case. The front panel (the most important panel) is comprised of two layers and is thicker than usual, and at it's thickest around the driver itself. Extra internal bracing has been drafted in order to reduce cabinet movement as much as possible. Even the port is quite different to the one used in the R Series and the Blade. KEF found that the port itself can produce standing waves, affecting efficiency. Stick your finger in the port and you'll be weirded out - the flare of the port is made of the usual material, but the inside is soft and flexible, in order to absorb these waves. If you tap the cabinet you'd be surprised - it seems even more dead than the Reference models. You can tell by listening to them that the UniQ driver is able to work freely of the cabinet.

Soundwise, they are more like studio monitors. The niceness of the R100's is gone. The R series sound very three dimensional, but the LS50 takes it further, able to project solid images in front of themselves. I use a few albums for demoing speakers - RHCP's Blood Sugar Sex Magic, while not a particularly refined recording, is very impressive in places, with extremely tight snare drums that most speakers just aren't neutral enough to reproduce properly. Dynamically, I'm surprised to say that they outdo the R300's (and many other speakers) quite comfortably.

Also, electric guitars are presented quite differently to most other speakers too. There's only a few other speakers that have done this to my mind - Royd's Minstrel and Miller & Kreisel's S150 satellite speakers are just two that have given me a new perspective on guitars in the past. Very few speakers present to you every note of distorted, grungey guitars, and to hear a track you know very well, only to find that the rythym or solo guitar is almost talking to you in a different language can sound quite odd at first, but once you settle into it you realise that many other speakers aren't giving you what they should be.

While they have pretty impressive bass for their size, these won't reach as deep as my R300's. They are more neutral though, making them a more informative speaker, and one that should be on anyone's demo shortlist who are looking for a small, informative speaker.

 

[alchemist 1]

[1] So how do the R100 compare to say b&w's cm1's ?

[2] Are Kef's ls50 worth the extra £200 ?

 

[Frank Harvey]

[1] So how do the R100 compare to say b&w's cm1's ?

Personal preference, but there will be certain benefits to the UniQ driver that are just fact.

[2] Are Kef's ls50 worth the extra £200 ?

That depends on your listening preferences. From a "tell it like it is" perspective, definitely, but some may prefer a slightly more laid back, 'nicer' presentation.

 

[nopiano]

Thank you so much, David. That report went far beyond my expectations - and it seems as though the speaker might too!

Thanks again.

 

[Frank Harvey]

No problem

 

[Exshopguy]

Personal preference, but there will be certain benefits to the UniQ driver that are just fact.

But aren't there negatives to coaxial driver arrangements too? Making a fancy baffle to keep the drive units under control and then placing the tweeter in the middle of what is essentially a moving baffle in the bass driver must affect its output? I think like all loudspeaker arrangements there are positives and negatives to all current methods. Personally I've always loved the sound of electrostatics as the best point-source but they have their own trade-offs in the bass region.

 

[Frank Harvey]

The HF in the UniQ is fixed - it doesn't move with the LF driver. The baffles has been made extra thick on the LS50 in order for the driver to work from the best base possible.

Everything has been done to minimise any drawbacks, and you'll probably find that the current UniQ is one of the most advanced out there at the moment. Their wide dispersion shows how well the driver has been designed.

 

[chebby]

The HF in the UniQ is fixed - it doesn't move with the LF driver.

Exshopguy didn't say it moved with the LF driver.

He said... "placing the tweeter in the middle of what is essentially a moving baffle in the bass driver" which is correct.

In a Uni Q speaker driver, the surrounding bass/mid cone material does form a moving baffle for the tweeter.

 

[The_Lhc]

The HF in the UniQ is fixed - it doesn't move with the LF driver.

Exshopguy didn't say it moved with the LF driver.

He said... "placing the tweeter in the middle of what is essentially a moving baffle in the bass driver" which is correct.

In a Uni Q speaker driver, the surrounding bass/mid cone material does form a moving baffle for the tweeter.

And yet they don't sound crap, as all the current reviews seem to indicate, so it appears there isn't a downside.

 

[Frank Harvey]

The main issue with UniQ drivers previously was the protruding roll surround of the LF driver. This deflected HF energy, affecting its dispersion. The new roll surround is flush, so this is no longer an issue.

I do have a link to an independent test of the Q100 driver, although I'm not sure I'm allowed to post it. It was rated very highly.

 

[chebby]

And yet they don't sound crap, as all the current reviews seem to indicate, so it appears there isn't a downside.

I've owned Uni-Q equipped KEFs so I know they can sound very good. I also know that Tannoy dual concentrics sound great too.

I know the concept works well. I was just pointing out to Dave that no-one was suggesting the tweeter was fixed to the bass cone and moved in-and-out with it. (I'm not aware of anyone using that arrangement in a concentric.)

 

[Frank Harvey]

I was just making sure we were on the same page Chebby

 

[The_Lhc]

And yet they don't sound crap, as all the current reviews seem to indicate, so it appears there isn't a downside.

I've owned Uni-Q equipped KEFs so I know they can sound very good. I also know that Tannoy dual concentrics sound great too.

I know the concept works well. I was just pointing out to Dave that no-one was suggesting the tweeter was fixed to the bass cone and moved in-and-out with it. (I'm not aware of anyone using that arrangement in a concentric.)

I know that but ExShopGuy was also suggesting it must negatively affect the output, so I'm simply pointing out that it doesn't appear to.

 

[Exshopguy]

I know that but ExShopGuy was also suggesting it must negatively affect the output, so I'm simply pointing out that it doesn't appear to.

I wasn't saying the speaker would sound bad, merely that while the driver arrangement will have some positives it will also have some negatives! If you cup your hands around your mouth and move them in and out as you talk it will affect the sound, the same principal would be relevant for putting a tweeter in the middle of a moving bass driver surely?

There's no solution that does everything perfectly that I've heard. Plenty of conventional driver speakers get great reviews too despite having their own flaws. I was merely questioning the FACT as Frank Harvey stated that the coaxial driver arrangment was better full stop. The arrangement certainly has some benefits for phasing and apparent point source, though that might not be a huge benefit if you're sitting six feet or so away from the speakers, by which time you'll be getting a lot of room reflected sound as well.

So, in short, I wasn't questioning the speaker's ability, but that it's driver arrangement was absolutely better than others.

 

[Frank Harvey]

I said there would be certain benefits that will be better, but I didn't say it was absolute

 

[Exshopguy]

I said there would be certain benefits that will be better, but I didn't say it was absolute

My bad! :rofl:

 

[chebby]

Looking carefully at large 'exploded' views of the R100 driver, it would seem unlikely that any treble output is going to 'bounce' off the bass/mid cone anyway. The tweeter sits behind it's own, static, combined cone and waveguide.

The 'cone' portion of this waveguide appears from a distance - when looking at the whole speaker - to be part of the surrounding bass/mid cone, but isn't.

An assumption on my part, admittedly, but it looks like the 'flare' of the tweeter waveguide's cone is slightly deeper than that of the bass/mid cone around it. This would mean a slightly narrower 'channelling' of the treble so no direct interraction with bass/mid cone area or surround (as Dave mentioned earlier).

This is more sophisticated than the older Uni-Qs that I used to enjoy. (Dome tweeter protected with mesh using the bass/mid cone as a 'horn' and no evidence of a treble waveguide.) I never had any complaints about my old Q35.2s so the compromises - even back then - can't have been that obvious

I can't find any large, exploded view pics of present-day Tannoy Dual-Concentric drivers to compare.

 

[Frank Harvey]

 

[MUSICRAFT]

I never had any complaints about my old Q35.2s so the compromises - even back then - can't have been that obvious

Hi chebby

Good speakers and at a fair price

All the best

Rick @ Musicraft