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 heardfor 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 LS3/5athe 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 edgeliterallyin 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.
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.