KEF Reference 207 loudspeaker Page 2
Setup was straightforward, the 207s working at their best when toed-in to the 10'-distant listening seat and positioned a few inches farther out in the room than the Canton Karat Reference 2 DCs—the front of the Uni-Q pods were 40" (left) and 64" (right) from the side walls and 58" from the wall behind them. With the speaker standing on its feet, the supertweeter is a high 50" from the floor, meaning that unless a tall listener sits in a director's chair, his ears will be well below the supertweeter's axis and therefore not receive much ultrasonic energy. The Uni-Q tweeter is 45" from the floor, which is still high. When I sit in my listening chair, my ears are 37" high, meaning that they were level with the point where the Uni-Q pod joins the lower-midrange enclosure. Fortunately, the exact listening axis didn't seem too critical with respect to frequencies below 10kHz, but I was aware of having to sit more upright than my usual relaxed slouch to get the full measure of the extreme highs.
Jumpers can be used to fine-tune the speaker's bass and treble balances. With neither of the two Bass Adjust jumpers plugged in, the low frequencies were extended but the midbass was a little recessed. I ended up using both jumpers, which raises the woofer level by a couple of dB.
Speaking of bass: Back in the mid-'80s, the original Reference 107 was the speaker that made me question my preference for minimonitors, a preference inspired by the ill-defined, "puddingy" nature of so much big-speaker bass back then. The 107's coupled-cavity bass loading produced low frequencies that were both extended and well-defined. The 207 builds on that legacy. The low-frequency warble tones on Stereophile's Test CD 3 (Stereophile STPH006-2, available from the secure "Recordings" page on our website) were reproduced in full measure down to the 25Hz 1/3-octave band. Although the 20Hz band was down in level, there was still useful output coming from the speakers' ports, and the 207 reproduced the "pat" of a close-miked kick drum with satisfying weight but without any boom.
The 207's combination of LF extension and clarity made it one of the best speakers I have used for reproducing electric bass guitar. Phil Lesh's instrument on "Attics of My Life," from the DVD-A re-release of the Grateful Dead's American Beauty (Rhino R9 74385, front channels only!), was reproduced with its delicate texture apparent, yet Pino Palladino's thunderous, live-sounding instrument behind Joe Cocker on "With a Little Help from My Friends" (Party at the Palace, Virgin 8 128332 5, CD) didn't descend into soggy boom. Every detail of Marcus Miller's much-lighter-toned instrument on Donald Fagen's "The Goodbye Look" (The Nightfly, Warner R9 78138, DVD-A, footnote 1), or his percussive picking and popping underneath Miles Davis' trumpet on the title track from Tutu (Warner 9 48429-9, DVD-A), was revealed via the KEFs.
At the other end of the spectrum, what about that supertweeter? The specification mentions a crossover point of 15kHz, which, as my hearing is pretty much shot above 16kHz, means that it shouldn't produce anything I can hear. Yet when I stood close to the speakers, I could hear quite a lot of high-frequency information coming from it with instruments like brushed cymbals. In fact, nearfield spectral analysis of each of the two HF units' outputs, with my hand over the other unit during the measurement, suggested that the top unit takes over considerably lower in frequency, above 10kHz, which in turn means that the lower tweeter covers just two octaves.
Notwithstanding these observations, the 207's high frequencies were clean and grain-free. While plentiful top-octave "air" was apparent, it wasn't exaggerated in the manner of the Cantons. In the mid-treble, however, a faint touch of hardness could sometimes be heard. Cantus' recent ...Against the Dying of the Light CD (see December 2002, p.63) is very critical in this respect, and I ended up auditioning it at lower SPLs than usual. This was also true for my choral recording on Test CD 3. The 207's superbly extended low frequencies also allowed me to hear much more of the traffic passing the centuries-old English church in which I made the latter recording.
Footnote 1: The DVD-A reissue reminded me that this early digital album is a cornucopia of great bass guitarists: as well as Marcus Miller, Anthony Jackson, Will Lee, and Abraham Laboriel.—John Atkinson