KEF LS50 Anniversary Model loudspeaker Page 2

Listening to the 1/3-octave warble tones on Editor's Choice, the LS50s reproduced these with full weight down to the 50Hz band. There was very little audible output below 40Hz, but there was no "chuffing" from the port. The low-pitched bass drum in my live recording of Elgar's The Dream of Gerontius (extract included on Test CD 2, Stereophile STPH004-2) had enough weight to be believable, as did my low D-flat on the bass guitar at the end of Erick Lichte's arrangement of "Deck the Halls," from Cantus's Comfort and Joy: Volume Two (CD, Cantus CTS-1205). When the synthesizer bass drops an octave for occasional notes to point a phrase at the end of "The Trader," from the Beach Boys' Holland (LP, Brother/Reprise K54008; perhaps Carl Wilson's finest creation), there was sufficient low-bass energy present to preserve the musical meaning.

However, while the kick-drum samples on James Blake's eponymous album (CD, A&M) weren't lacking impact, when Blake adds a thunderous 16th-note subbass line in "Limit to Your Love," the LS50 was obviously having to work harder than it would like to at anything approaching musically satisfying levels. Later in the song, when the subbass line comprises longer, held notes, the LS50 recovered its equanimity, though with a touch of doubling.

At the other end of the spectrum, the LS50's high frequencies sounded very clean, with no grain or steeliness. This is a high-quality tweeter. The LS50's treble did sound a little soft at first, compared not only with the DeVore O/96 (reviewed by Art Dudley in this issue), but also with the mellow-balanced Sony SS-AR2 (reviewed by me in October). The ostinato hi-hat cymbal in "The Trader" sounded a little subdued, though cymbals in more recent recordings, such as my own Rendezvous (CD, Stereophile STPH013-2), were reproduced with a natural tonal quality and precise, stable stereo imaging.

Pink noise revealed a slight emphasis at the top of the midrange, but this region was otherwise superbly clean and clear. The LS50's unforced transparency and lack of coloration in the mids and highs effortlessly untangled the complex vocal lines in "Measurements" from James Blake. Richard Lehnert's speaking voice in the Channel ID and Phase tracks on Editor's Choice sounded natural and free from coloration. Joni Mitchell's tobacco-damaged contralto in "At Last," from Both Sides Now (24/96 ALAC file ripped from DVD-A, Reprise 47620-9), sounded suitably sultry and smoky.

At the start of the review period, I was in Los Angeles producing the vocal sessions for the opera Cooperstown, composed by Positive Feedback Online contributor Sasha Matson. At the end of the review period, Sasha sent me a CD with some test mixes. Listening to our two sopranos, Julie Adams and Carin Gilfry, and comparing what I was hearing through the KEFs with my memory of what I'd heard live at Bill Schnee Studio, I would go so far as to say that the LS50 is one of the finest speakers at reproducing female voices that I have heard—for less than what you can pay for a set of high-end interconnects!

The obvious comparison was with the LS3/5a, in the form of my 1978 Rogers pair. This model has long been one of my references for both auditioning and measuring, and I am intimately familiar with its sound. Against the LS50 the Rogers sounded distinctly nasal-colored. There was more top-octave energy apparent than with the KEF, which added "air" rather than brightness, but also lent overcooked rock recordings a "spitty" edge. The LS50 sounded considerably more neutral than the vintage speakers in both the midrange and treble, with naturally recorded cymbals sounding less like textured white noise.

Low-frequency clarity has never been a big strength of the LS3/5a—the upper-bass bump that makes it sound larger than it has a right to also blurs the definition of low-frequency instruments. The LS50 had the edge—literally—in this region. While its upper-bass balance was similar to the LS3/5a's, the sound of the piano's left-hand register was cleaner and better defined, especially at high playback levels. Bass guitar had superb clarity. However, the KEF's bass was somewhat suppressed, the older speaker's sealed-box alignment allowing a little more of the lowest frequencies to be heard.

Next up was the identically priced but somewhat larger Bowers & Wilkins CM5 (reviewed by Robert J. Reina elsewhere in this issue). The CM5 was noticeably more sensitive than the LS50, and had a lighter, airier balance, but was also slightly laid-back in the treble. Both speakers had very clean upper-frequency presentations, though the CM5 was less forgiving of ticks on LPs. However, the B&W's bass was usefully more extended than the KEF's.

Which speaker you will prefer will depend very much on your tastes in sound and music. Classical orchestral, solo piano, and vocal recordings were better suited to the more neutrally balanced KEF, and rock to the B&W, with its more laid-back low treble and more extended low frequencies. On balance, I preferred the LS50.

Summing Up
It is rare to find a loudspeaker that offers this combination of clarity and neutrality. For KEF's LS50 Anniversary Model to do so for a penny under $1500/pair makes it even more remarkable. This thoroughbred both shows a clean pair of heels to the venerable LS3/5a and, within its limits of dynamic range and bass extension, will provide Class A sound for those with small rooms. Recommended. Highly.

GP Acoustics
US distributor: GP Acoustics
10 Timber Lane
Marlboro, NJ 07746
(732) 683-2356

Audio Asylum Bruce from DC's picture

Being a dedicated "stand-mount" guy and something of a cheapskate, this review got me really excited.  Maybe I should replace my 10-year old Joseph Audio RM7si Signatures!

Imagine my disappointment when I went to KEF's US website and tried to find a dealer.  Even at maximum range from my location -- Washington DC -- I came up empty.  There is a local dealer, but it stocks only KEF's low-line stuff, not any of the fancy products (including the Reference Series).

Assuming that one would agree that Washington DC is not the sticks, it might be worthwhile for Stereophile to enquire of KEF exactly how many US dealers the company has which stock this product -- or the Reference series for that matter.

Sergei's picture

The reason you can't find a pair Audio Asylum is because KEF in their wisdom decided to insult all of their loyal dealers by offering this product ONLINE ONLY!

I am a Canadian Dealer(soon to be ex-dealer now) for KEF. We had a clent want to hear a pair of these and most likely purchase due to being a long time KEF fan. To both of our surprise when I contacted my KEF rep he explained this was ONLY available through the KEF online store.

We played him a pair of other bookshelf speakers he happily purchased instead.

There is really no logic as a business man and Hi-Fi enthusiats that KEF would want to snub their dealer base with an "Anniversary" product. We were even considering displaying the Blade's in our showroom...


hcie95he's picture

In the review the LS50 is compared with the B&W CM5 and the LS3/5a. In the past John reviewed also the Harbeth P3ESR and the Spendor SA1, which are both more expensive. I am wondering if the LS50 is in the same league as the Spendor and the Harbeth?

By the way I am surprised that KEF doesn't sell the LS50 in the US via their dealer network. In Europe you can buy and audition them via their dealers.

norcalhifiguy's picture


Sad to see the previous comments, but as the owner of small audio shop in a very small town I can say with absolute authority that these are indeed available from direct dealers. (I can't speak to the Canadian issue as we are in the US)

We are thrilled to have these on display in our main listening room and must say they live up to the great reviews. These are amazing little speakers.

Please, do seek out and support your local independent audio dealers. 

These are people that love great audio as much as you do.

Hear them in person. Buy them locally!

audiodoctornj's picture

As one of KEF's highest level dealers, Audio Doctor, has the Blades, the entire Reference Series, R Series, Q Series, and T Series products as well as the LS 50, I can tell you they are available at select dealers, I don't know the issue with the Canadian distributor but they should be available to them as well.

WIth that being said, I do feel that is unfortunate that KEF does not have more stocking dealers with the LS 50, or with a wider range of their products.

The current KEF lineup is some of the best products the company has ever produced and in particular the BLADE represents $60,000.00 and above levels of performance for $30k, the BLADES are amazing speakers!

I feel that there are a few issues going on, Stereophile and the Absolute Sound do not really do comparative anaylsis of one product to another in their reviews, if they did and were not affraid to stand up to their advertisers, they  would proclaim that the BLADE is a bargin for the abolute top level of performance that they give and would recommend that anyone looking at a Wilson, Magico or YG etc should give the BLADES a listen before considering spending more on anything else.

We did the High End Audio Show in NYC last year, and our setup with the BLADES and all Chord Electronics sounded as good as any of the other setups at the show including a $300,000.00 plus YG setup and another mega dollar MBL setup and these were $30k speakers standing up agains $110k speakers!

So in summation, KEF makes fantastic products, has a weak dealer network, and needs to revamp their advertising and marketing to get more people excited by their products.

You should hear a pair of LS 50 setup with the really nice little KEF R 400 sub you have a roughly $3k package that sounds remarkable, huge soundstage, shocking dynamics and great transparency!

If anyone wants to visit our shop call 877 428 2873 and make an appointment to hear these incredible little jewels.  

10sephirot's picture

The little KEF sure is getting good reviews.  Lets face it looks count also.  It made me think about what stands would look best.  In my opinion the Usher RSW-708 in walnut would be a very special look:

The KEF plus the stands I subjectively think look best is a $2000 proposition. 

I'll go ahead and match that up to the Vincent Audio SV-236 in black:

another $2000.

I'll go ahead and add the Musical Fidelity MMF-51SE:

Yeah well anyway that is another grand.   $5000 total.

I told all this to Santa and I got thrown out of the shopping mall.

But in all seriousness this is what a good review makes us do: dream. 

Thanks Stereophile.  Another afternoon wasted daydreaming:)

JRT's picture

In the measurements, the waterfall diagram showing polar response in the vertical plane passing thru the voicecoil centerline appears to be much smoother than the polar response in the horizontal plane.   So I think the first tweak for improved performance, clearly demonstrated in the measurements, would be to lay the speaker on its side.  

prof's picture

In the measurements, the waterfall diagram showing polar response in the vertical plane passing thru the voicecoil centerline appears to be much smoother than the polar response in the horizontal plane.

Umh, no. You've been fooled by the difference in scales. The scale on the vertical waterfall plot is ±45°. The scale on the horizontal waterfall plot is ±90°. At ±45°, the horizontal dispersion is as-smooth or smoother than the vertical dispersion.

techblogpool's picture

Hey guys, I just made an unboxing of these:

ryebread's picture

Quest For Sound in Bensalem, PA

bought them last week, epic speakers

wgb113's picture


Curious what amplification both QFS and you are using.  I might try to head over there for an audition.


Gradofan's picture


The sound I'm getting from this set up is "stupendous!"  Don't think it can get any / much better - certainly not for less than 10X the price!


Using the Sony  XA5400ES SACD/CDP (the best there is), into the Anti-Mode 2.0 as a pre and DSP to eliminate the "room boom," into a tube buffer, into the Class D Audio amp into the LS50's and R400b produces real "you are there" sound.  Incredible detail, resolution, tone, tenure, texture, stage, image, bass, mids and treble... etc., etc...  


Hard to believe... really... 


And just an incredible value!


wgb113's picture

Everything I've read about the LS50s indicate that they're great for a small room.  My room is REALLY small @ 10'x12'x9'.  It's been acoustically treated but placement of the speakers and listening position results in a near-field setup.  Are the KEFs going to work well in such a setup?  It seems their manual recommends 6'-10' between the inner sides of the cabinets before toeing in.


Azani's picture

I've just purchased the pair after searching high and low for floor standers to replace Rogers LS2a/2. Auditioned Harbeth P3ESR, like it but thought it sounded like big voice coming out from small mouth. Haven't got the chance to audition any Spendor monitors tho. 

Anyway, my room is also small (8x13)' with acoustic treatment but still able to handle LS50 quite well. Generally, a slight enhancement from Rogers LS2a/2, livelier that is.

just yesterday, started to experience sudden annoying jerks and "tone switching" (for the lack of better word) on the right speaker whenever CD is played. It was fine the day before. Yet to figure that one out. Anyone experience it?


dc_bruce's picture

and could not be happier. I concur completely with the comments of all 3 Stereophile reviewers. The only advantage of the long-out of production Josephs is that they go solidly down to the low 40 Hz range, reproducing the fundamentals of string and electric bass pretty well. Other than that, the little KEFs have it all over, and I really can't fault them, within reason. I say "within reason" because its unreasonable to expect a speaker of this size to reproduce the weight and scale of a symphony orchestra at full power. That said, these come much closer than you would expect; and they are not as bass-deficient as I had expected.

I am running them (eegads!) on a sort of bookshelf (actually a built-in cabinet) with about a foot clearance from the wall behind them. I decided to use the partial foam plug to attenuate the bass for the most natural sounding response. Of course, I'm using an old REL subwoofer, so getting the last few Hz of bass extension from the KEFs is not necessary.

If you're not trying to fill a large room and are not looking for stomach churning loudness, it's hard to go wrong with these. They seem to impart no particular characteristic of their own to the sound. I running them with a BAT VK-300x integrated (150 wpch @ 8 ohms/ 300 wpch @ 4 ohms) which seems more than enough power.

Ali's picture

Is there any differences between anniversary and non anniversary model?

John Atkinson's picture
Ali wrote:
Is there any differences between anniversary and non anniversary model?

Cosmetics only. The sound is the same. (I bought a pair of regular LS50s after reviewing the "Anniversary" edition.)

John Atkinson
Technical Editor, Stereophile