KEF LS50A two people review, or a four ears' work ...
KEF LS50
KEF LS 50 is the star of the moment. Everybody' s talking about it and would like to test it. Many have already bought it. It's a small size loudspeaker, very, very well refined, classical and modern at the same time. It has two concentric loudspeakers that originate from the previous UniQ series of the English brand and upgrade the quality of these loudspeakers. The LS 50s are born to celebrate the 50 years of activity of the enterprise. This brand is well known to audiophiles that are now 50 or 60, thanks to projects such as the 104 with a passive woofer or the 105 that were the main competitor of DM6 by the evergreen Bower & Wilkins, aka B&W.
It's easy to speak about KEF and restate facts that are well known - it's a British brand, born in the 60's, known for its first models and famous in the 70's for models such as Coda, Calinda and the aforementioned 104 and 105. Up to the latest models that have in their top range the Muon. It's a representative of British Sound and so on ... - but it's not easy to find something new to say. KEF's history (KEF manufactures loudspeakers but also the drivers and sells them to other manufacturers) can be found in their website, where you can also find a gallery of their entire catalogue. There are also the Cadenzas that I possessed some time ago. I'd love to have them at home once again, together with another British icon, the Splendor BC1. I want to underline that old brands such as KEF are a certainty when purchasing something because their permanence on the market is a clue of their seriousness and of their will of continuous improvement in the design and in the achievement. 
KEF LS50
It may be useful to mention the fact that the LS 3/5 , the small BBC monitor, Mount KEF proprietary speakers. But how are these small KEF made? As soon as I saw them, I thought that they were gorgeous and therefore expensive, more than they actually are. They have a beautiful finishing, a black mat synthetic front rounded panel where a copper UNI-Q driver is mounted. The small woofer and tweeter's membranes are metallic. The rest of the cabinet is made of wood and is reinforced inside. The inside is visible on the manufacturer's website. Their weight is 7 kilos each. The painting is mirrored like that of pianos, and the KEF logo is on the upper panel and has a mat black finishing. On the back panel we find the reflex port and the single-wiring connectors.
Specifications: Frequency response is at -3 dB at 79 Hz (-6 dB at 74 Hz), power handling is 100 W and the sensitivity is 85 dB, with a maximum SPL of 106 dB. Let's take a look at the bass response. As I said the loudspeaker has a reflex port. In the packaging, that is very well done and contains both speakers, there are the instructions and also two plugs that can be inserted in the reflex port. The manufacturer suggests to use the plugs only when the distance from the back wall is smaller than 50 cm. I had in my room, some 10 years ago, speakers that had the same possibility: the Tannoy D100. I prefer now, as I preferred then, to leave the reflex port free. When the reflex port is closed the sound is more harsh and mechanic in the low range and these loudspeakers don't need this. The low range is really accurate and this is something rare for a small volume loudspeaker. At first in fact these loudspeakers seem to have no low frequencies, while they only lack the enhancement of the medium-low rangethat is used to make the speaker seem bigger than it is. In fact when the deep low range is present it can be heard with great clarity and pleasure, and it is surely more present than that of their competitors. 
KEF LS50
LS 50s are British in the highest sense of the term: controlled, precise, without exaggerations. They are very determined in the transient and dynamics does not seem to suffer even in the low range. The small 13 cm cone is under pressure only when the volume is really too high. In this last case the top range seems to be out of control but considering the price of the loudspeaker I think this is not a problem. Secondly, the speaker is transparent and sometimes to amend to this situation it's enough to change the power cable. Just an example: I started out with Kimber Kable 4TC, a cable that is not dampen in the acute range, I switched then to the Swiss Heil/Precide ACE that has a different answer in the high range and that sensation of stress disappeared. So be careful because the LS 50 are really transparent. About amplifying them, I think that the valves of the Olympia Audio preamplifier, together with Wired4Sound ST 250 Class D amplifier, seemed appropriate to obtain a natural and captivating sound from the LS 50s.
KEF LS 50s have been connected to the following system: Bauer Audio DPS 2 turntable, Mørch DP6 tonearm, Denon DL S1 and Denon DL 103 cartridges, Revox B795 turntable with Ortofon MC Vivo Blue cartridge, American Hybrid Technology –P e Lehmann Black Cube phono preamplifiers, Olimpia Audio Guglielmo II and Spectral DMC12 preamplifiers, Spectral DMA50 and Wyred4Sound ST 250 power amplifiers, Audio Note AN-E SPx loudspeakers, Systems & Magic, Kimber Kable, Audio Note, YBA and other cables. The feature that is evident straight away is the ability to reproduce with great care the instruments on stage. I have used a recording that is not new - actually it's quite old - The Messiah by Haendel directed by Hogwood (Oiseau Lyre CD). The orchestra is well reproduced and the position of the singers is in front of the orchestra, the choir is in the back but there are no empty spaces between one group of singers and the other. Focusing is really good and different according to the toe in that each one decides. With a toeing towards the listening point, so to see only the front panel, the image is very sharp, maybe too much. If the loudspeakers are positioned higher than 60 cm the voices have a more natural height. (At 60 cm it's just like being in the gallery, but in the churches you usually listen sitting in the nave that is lower than the stage prepared). A lower stand helps the presence of the lower portion of frequencies. The voices are beautiful, without grain, clear, dynamically free; at a high volume voices become a little harsh but the volume must be really high, almost at the speaker's power limit. 
KEF LS50
Their monitor vocation and their ability to reproduce the instruments inside the recording is clear once again when listening to the Oiseau de Feau by Stravinski (Decca, Dorati ) both CD and LP. In this recording some solo instruments are put fairly closer to the listener, because the sound engineer had decided so. With the cello this "manipulation" is really evident and not natural as it seems to detach itself from the orchestra and get closer to the audience. LS50s evidence this peculiarity and this is something that not all low cost systems can do. This recording puts in evidence the percussion sound that is so full and round that surprises the listener. The bass in "Last Train Home" by Pat Metheny (LP Geffen Records), is well pitched and deep if related with the loudspeaker and woofers dimensions. The cymbals are present but never annoying; the smallest dynamic variations are present and the timbre is never too open. Maybe more definition at the extreme top end would be appreciated but we have to keep in mind that these loudspeakers cost around 1000 euros a pair.
And now let's talk about the user's manual. The neighbours test is successful. These loudspeakers are very enjoyable when the volume is loud but are just as much enjoyable when listened to at a low level. Of course when you listen to rock music high volume is mandatory for the specific characteristics of this kind of music and it's obvious that a small loudspeaker cannot compete with a big loudspeaker with a 12" or bigger woofer, as for music enjoyment. KEF suggest a 60 cm stand. I have nothing to say about it but I think you should try also a height of 70 because at a high volume, if the loudspeaker is not too far from the back wall, there is a better perception of the soundstage. If you keep the loudspeakers one meter from the back wall with higher stands you'll loose more or less one ounce of bass. As for the positioning in a room I have obtained the right balance putting the loudspeakers 60 cm from the back wall and toeing them towards the listening point so as to see barely the internal side of the cabinet. If you put them closer to one another and you keep them parallel to the back wall the bass will be more tonic, the medium low range as well, but the high range will be less clear. As usual you will have to find the right positioning in your room, moving the loudspeakers a bit, thanks God loudspeakers are light weighted and it won't be too difficult to move them back and forth. To conclude, I just want to say that for a thousand euros you'll take home an excellent product with just few small flaws; it's also a nice piece of furniture as these loudspeakers are really good looking. There has been much ado about these loudspeakers for a good reason. I noticed them at Top Audio Show last year and at last I have been so lucky to review them carefully in my room. A good amplification with at least 50 Watt for each channel, a good source and you'll have a very good sound not only for newbies but also for expert audiophiles. The real deep bass - 30 or 40 Hz - is missing and the medium high range is a bit forwarded but this won't undermine the possibility of a high quality listening. Acknowledgments are mandatory. The Italian distributor did not answer to our requests to have this loudspeaker for a review. We have had the chance to review it thanks to Marinella Malerba, the owner of the Milan shop Hi-Fi Club. She deprived herself of these loudspeakers for a long period so Angelo and me want to say thanks to her publicly. Domenico Pizzamiglio Angelo Jasparro's listening
Unlike our usual policy I have read Domenico's impressions before writing mine that anyway were already very clear in my mind. I did it because I like to evidence the differences of the positioning in the room of these small loudspeakers that were born to celebrate the 50th anniversary of one of the legendary brands of the international hi-fi. I have used 60 cm stands and I have noticed that in my room the soundstage is credible. The distance from the back wall is about 70 cm. As you can see in the picture the back wall is composed by the JBLs 4350 whose woofers are as big as the LS50s, including their cabinet. I have also worked on the distance from the side wall that if excessive diminishes the soundstage and takes away a part of the bottom end. Once found the right position, you can work on the toeing of the loudspeakers that in my case was just few degrees. As you probably know I prefer a larger soundstage to a false deep one. The LS50 have been connected to the following system:
turntable Basis 2001, tonearm Graham 2.2, cartridge Scan Tech Lyra Helikon, phono preamplifier: Einstein "The Turntable's Choice", CD/SACD player dCS Puccini + Puccini U-Clock, preamplifiers: MBL 4006, NuForce HAP-100, power amplifiers: Bryston 7B ST mono, NuForce STA-100, loudspeakers: JBL 4350B, interconnect cables: MIT Oracle MA-X Proline, MIT Shotgun S2 RCA, Transparent Super XLR, Transparent Super RCA, LAT International XLR, loudspeaker cables: MIT Magnum MA, Vovox Initio, power cables: MIT Shotgun AC 1, Black Noise Pearl and others DIY, mains filter: Black Noise 2500. I have been wanting to review these loudspeakers since the last Munich High End. When I saw the presentation they impressed me with their sound. They sounded well in a very big room where one thinks that the sound could not be enough due to the speakers small dimensions. And here they are now in my listening room after having been in Domenico's room. What can I say? As you know one of the nicest things of our "hobby" is that things happen when you least expect them. The first thing I noticed is the incredible sound of the cymbals of the percussions of Jack Dejohnette in the CD "Tokyo 96" in which he plays in a trio with Keith Jarret and Gary Peacock (ECM). It's one of those sounds that makes you look up and stare as the cymbals seem to be right in front of you. And this is just one example of the many surprises that came from this small loudspeakers. In fact it's small but great and it's going to give much more than promised, as it always is with the high quality products that have a great brand behind them. A brand that does not need a good advertising campaign to let you know how good their product is. Well, for a thousand euros these small KEF are a small miracle as for the technology of the project and the final result. If you can afford them, buy them for a secondary system or as computer's loudspeakers; amplify them well but don't let them go, even if you have a bigger system. You'll have a rich sound that will make you feel behind the mixing monitor of a trendy recording studio but sound reproduction will remain pleasant and uncommon for such a small loudspeaker. You won't need to attend auctions any more to buy old - or new - LS 3/5 no matter what their brand is. Or at least this is my opinion. Angelo Jasparro Translation: Francesca Rubino |
