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KEF R107 loudspeaker John Atkinson 1991 part 3

Time for truth. I reached for that same Sibelius 5 recording (London 410 016-2).

Have you noticed that when something is working right in the system, it seems hard to concentrate on the hardware? Such was the case here. By the end of the symphony, I had forgotten what exactly it was I was supposed to be listening for.

Oh yes, that bass discord. I put the third movement on again, this time trying to shut out the music. Mmmmm. Just as I remembered it from the original 107, the E-flat and F close but far, melded but differentiated—but there's so much more going on, so much wider a…

KEF R107 loudspeaker John Atkinson 1991 part 4

The adjective "neutral," however, while held to be a positive quality in a hi-fi component, can also imply a lack of commitment, a shrinking from extreme positions. Thus it was with the KEFs. "They're a little polite?" ventured Tom Norton after I forced him to listen to the Dorian Pictures. Yes. They are. Compared with, for example, the Avalon Eclipses or Wilson WATT 3/Puppy combination, the R107/2s lose a little immediacy, offering a less dynamically vivid sound picture. They are also less forward-balanced than the similar-in-concept B&W 801 Matrix. But they still present all of the…

KEF R107 loudspeaker 1991 Measurements

Sidebar: 1991 Measurements

Looking first at the performance of the KUBE, its distortion and input and output impedances measured to spec, while fig.1 shows its fundamental response with both contour controls set to their 12 o'clock positions. Note that the treble is shelved down by 1dB while the gentle, 2dB boost below 1kHz is presumably to compensate for the midrange driver's diffraction loss. The sharp rise in output level below 50Hz is to extend the speaker's bass below the bandpass enclosure frequency (where a slight, 2dB suckout compensates for what must be a slightly underdamped…

KEF R107 loudspeaker Thomas J. Norton 1995

Thomas J. Norton wrote about KEF's Reference Series "Raymond Cooke Special-Edition" 107/2 in October 1995 (Vol.18 No.10):

It's a little mind-bending to recall that KEF first introduced their Model 107 loudspeaker in 1986. KEF, like most British loudspeaker manufacturers, tends to be conservative when it comes to its high-end models. Why mess with a good thing? The Model 107 has never been a radical design—that wouldn't be KEF's style. But the original 107 built on a solid background of innovation from KEF products in the immediately preceding years.

Take the twin coupled-cavity…

KEF R107 loudspeaker Thomas J. Norton 1995 part 2

"Whoa! What happened?" I blurted aloud to no one in particular as the first bars of music rolled toward me. The left-right spectral balance was now all wrong. One channel appeared to have lost its top end, with a resultant skewing of the sound to the unaffected side. I listened more, to other material. Same result. I pulled the speakers out and set them close together. No change. I reversed the midrange/tweeter heads (they come packed separately and may be easily installed or removed by the user). The problem moved with the change in heads, indicating that it lay with the tweeter itself.…

KEF R107 loudspeaker Thomas J. Norton 1995 part 3

That quality was enhanced by a bottom end that tilted more toward a full, rich quality than punchy tightness. In this respect, it also differed from the Thiel CS7. But when I say "tilted," I really mean it. In my large listening room, the 107/2 was full-bodied through the bass range, but in no way overblown. Bass definition was good. There was no muddle or confusion. The richness did reduce the overall transparency of the sound compared with that from a loudspeaker with a vise-like grip—particularly through the mid- and upper bass.

I did note a slight sonic fog in this region,…

KEF R107 loudspeaker Specifications

Sidebar: Specifications

Description: Three-way, floor-standing loudspeaker with Conjugate Load Matching, Coupled-Cavity bass loading, and line-level equalizer. Drive-units: 1" (25mm) metal-dome tweeter, 5" polypropylene-cone midrange unit, two 10" (250mm) pulp-cone woofers. Crossover frequencies: 160Hz, 2.5kHz. Frequency response: 20Hz-20kHz ±2.5dB (-6dB at 18Hz, Q=0.5). Directional axis characteristics: within 2dB of reference up to 10kHz for ±10 degrees vertically, ±30 degrees horizontally. Position of reference axis: 40" above cabinet base, not including feet. Nominal impedance: 4…

Diapason Adamantes II loudspeaker

Beauty is in the eye of the beholder—but all too often there is little of beauty to be found in high-end audio. In these aesthetic dark ages, we have been indoctrinated to forsake grace and elegance; we all know that every underlying penny should be spent only in the pursuit of superior sonic performance.

Bull! Where tradeoffs are necessary, sonic performance should indeed come first. Design decisions such as the ones which led to the inclusion of inconvenient dual volume pots on the Audible Illusions Modulus 3 preamp and to the innocuous grille/sock over the price/performance-…

Diapason Adamantes II loudspeaker Specifications

Sidebar 1: Specifications

Description: Two-way, reflex-loaded, stand-mounted loudspeaker. Drive-units: 6.7" (170mm) plastic-cone woofer; 0.85" (20mm) soft-dome tweeter. Frequency range: 34Hz–20kHz (no limits given). Crossover frequency: 2.5kHz. Sensitivity: 91dB/W/m. Nominal impedance: 6 ohms. Minimum impedance: 3.7 ohms at 300Hz.
Dimensions: 14.4" (365mm) H by 9.5" (240mm) W by 15" (380mm) D. Weight: 21 lbs each (9.5kg).
Serial numbers of review samples: 1020A/B.
Price: $3998/pair (matching stands cost $750/pair), 1996. Approximate number of dealers: 15 (1996).
Manufacturer…

Diapason Adamantes II loudspeaker Measurements

Sidebar 2: Measurements

While my estimate of the Adamantes' B-weighted sensitivity was below specification at 88.5dB/2.83V/m, this is still high for a small speaker. Its plot of impedance magnitude and phase (fig.1) dropped to 3.75 ohms at 230Hz, but the speaker is otherwise a moderate load for an amplifier to drive. The tuning of the rear-mounted port can be seen from the saddle in the bass to lie at 49Hz.

Note that a couple of wrinkles between 300Hz and 500Hz can be seen in the fig.1 traces, indicating some resonance problems in this region. This is confirmed by fig.2, which…