One of the universal laws of hi-fi is that a loudspeaker’s sonic ability is in inverse proportion to its aesthetic beauty. True, the Holy hi-fi provider has granted several high end panel speakers a special exemption to this rule, but that aside it sadly seems to apply to almost everything. So when I first unpacked this little box a year or so ago, I was expecting it to sound like a pig. Put simply, it looks lovely and I struggle to think of any other £800 mini-monitor that compares in styling and finish. The 130mm ‘rose gold’ magnesium/aluminium mid/bass driver is the centrepiece, and reminds those who have forgotten what a beautiful colour copper is – because the KEF is very close. Set into this is a 25mm aluminium high frequency driver, as is the custom from the company’s Uni-Q loudspeakers; the idea is to give a ‘point source’, so the sound comes from the same place in space, regardless of whether it is treble, midrange or bass. The two drivers cross over at a fairly conditional 2.2Hz.
The LS50 still wouldn’t look the part if the cabinet was averagely turned out, which is why it has received an immaculate piano black lacquer finish; its surface resembles a perfectly still pond, looking like semi-translucent glass. A slight curve to the front baffle breaks up the boxiness, and the enclosure itself is made from a special polyester resin combined with glass fibre and calcium carbonate. It’s wonderfully solid, and weighs a decent but not exemptional 7.2kg. Measuring 302x200x278mm is a small-to-medium sized box but nothing exceptionally diminutive, and uses a conventional rear-mounted reflex port. KEF claims it has a sensitivity of 85dB, so you’ll need a powerful solid-state amplifier – think in terms of at least 50W RMS per channel. Quoted frequency response is 79Hz-28kHz (+/- 3dB), which is decent enough for a box of this size.
Contrary to my worst fears, the LS50 proves to be an excellent performer. Interestingly, you can hear its faults quite clearly, but KEF engineers have worked around them and the result is that they never intrude or detract from what is in other respects a really great loudspeaker. The bad news first; the box isn’t inaudible. There’s a sense that there’s a slight coloration in the bass, nothing major but you definitely hear some overhang on powerful transients and this holds right up to the midband. Ultimately, the speaker needs to be more rigid and better braced, but that would require more expense and thus a higher price. The other issue is the reflex port, which like a dull toothache is always there with any ported box; try an infinite baffle Spendor D1 (at twice the price) for example and you’ll hear the LS50’s reflex loading giving a slightly softer and plummier bass than you’d hope for. Thirdly, the drive units aren’t invisible either, more of which later…
Still, none of this stops the wee KEF from sounding great. Like a special girlfriend, you love her in spite of her faults. This speaker has a natural musicality to it that’s really rare at the price, or indeed anywhere near it, and it enables the listener to completely forget he or she is listening to a loudspeaker. You get lost in the music all too easily, and it’s a truly immersive experience. Part of this is down to its brilliant soundstaging; the KEF projects elements in the mix out into space like a laser beaming patterns all over the night sky. It is so bold, so big, so assured and so out-of-the-box. Everything feels so light, fleet of foot and rhythmically engaging. The LS50 has fine soundstaging and its depth perspective is excellent too; doubtless down to that Uni-Q array.
Tonally it’s quite a crisp and spry speaker; there’s a touch of warmth to the upper bass (there’s little lower bass to speak of), but moving up into the midband you get a clean, delicate and finely etched sound, great at carrying the dazzling transients of strummed steel string guitars, for example, yet clean and even with edgy female vocals. There’s just a touch of extra daylight in the upper presence reason, and this combines nicely with that warmish bass to give a lively, vivid yet weighty sound. Treble is good, spacious and airy with a nice sheen to cymbals; few £800 designs have better HF units, although it’s still no match for the JET tweeters in ELACs, for example, or other such exotic designs. Everything sounds even and all-of-a piece, making for a well voiced loudspeaker that sounds detailed and couth across a very wide range of music.
KEF’s LS50 is a great little loudspeaker. It’s not the best box in the world but sounds far better than it has a right to at the price, and is also beautifully finished and extremely attractively styled. It’s a particularly strong product for this venerable company, and a fitting celebration model for its fiftieth anniversary.