KEF R100 speaker review

Hi Andy

Thanks.

All the best

Rick @ Musicraft

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..

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. 

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!

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.

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

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

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

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.

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

Thanks again.

No problem

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.

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.

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 rubbish, as all the current reviews seem to indicate, so it appears there isn't a downside.

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.