KEF 107 (Late 1980s)

The KEF Model 107 was the flagship of KEF's Reference Series in the late 1980s. It was a three-way floor-standing speaker with two 10-inch woofers, a 5-inch midrange, and a 1-inch dome tweeter. The unusual part was the two-piece build: a woofer section, and a separate upper "head" that housed the midrange and tweeter. The head could be swiveled horizontally, so the listener could aim the upper drivers for precise imaging. Mix Magazine (October 1987, p.206) described it as a way to "optimize imaging" by adjusting the MF/HF module in the listening room.

The 107 used KEF's coupled-cavity bass-loading system, which got deep bass out of a relatively slender cabinet. An external equalizer, the KEF Universal Bass Equalizer (K-UBE), came with the system. HiFI-Stereo (June 1986, p.18) reported that it let the user adjust the bass rolloff frequency from 20 to 50 Hz, plus rolloff damping and contour. The K-UBE was not a general-purpose processor. It was made specifically for the Model 107, along with the Model 102 and Model 103/3.

Measured performance was strong for the era. Audio (February 1988, p.70) recorded a frequency response of 20 Hz to 20 kHz ±2 dB (with the equalizer engaged), a sensitivity of 90 dB for 2.83 V at one meter, and a maximum output of 112 dB on program peaks. Impedance was a flat 4 ohms, and the magazine recommended amplifiers between 50 and 300 watts. The system used KEF's impedance load-matching crossover, designed to get maximum performance from the driving amplifier. As part of the Reference Series, each 107 was built to close tolerances so that every production unit matched the laboratory reference. KEF's own advertising leaned on that claim heavily, calling the model "the pinnacle of this Reference technology" (Audio, September 1989, p.115).

Surviving documentation on the 107 is limited to period reviews. No original manual, production years, or pricing appear in the record. The reviews show a swiveling mid/tweeter pod for imaging, an external equalizer for room-specific bass tuning, and a driver lineup aimed at reference-level performance.