Stereo Amplifier

Review: KEF Model 101 Speakers

Though it is very tiny, only one-tenth the volume of the KEF Model 105, there is evidence that this speaker has received the same attention by its designers. Indeed the problems of designing a high quality speaker of small dimensions are greater than for a large one. The two KEF drive units are computer matched to each other within 0.5dB. They are housed in a very strong 6-7 litre cabinet veneered on all sides, including the front, which is normally covered by a framed grille of acoustically transparent cloth. Connections are via spring-loaded push-in terminals and there is an elaborate self-powered protection circuit which KEF call S-STOP (steady state and transient overload protection). This monitors the input voltage to each of the drive units and, if the voltage exceeds that level corresponding to the safe thermal limit, operates a red warning light and a relay to introduce 30dB attenuation. Monitoring then continues and full signal is restored when safe voltage levels exist.

In practice, while we found the KEF Model 101 to be of below average efficiency, we could not reach overload conditions without raising the amplifier output to a level at which acoustic power was well-nigh deafening. So we suggest an amplifier of at least 20 watts rating, but there seems no point in specifying an upper limit: the Model 101 will handle anything. Directional spread was smooth and consistent in all planes, which we regard as a very good feature, making positioning uncritical—though KEF suggest the speakers should be about 1 metre above the floor. The white noise test revealed unusually smooth performance over the whole middle and upper register. Extreme bass was less well defined than with our larger control systems, as might be expected, and the slight colouration accompanying this clouding at the bottom end could be distinguished on both music and speech—though the guitar was reproduced with great realism. On extended listening, the virtues of this speaker became more and more apparent, and it was preferred to many much larger systems at the same price or higher.