Loudspeakers

'Music Integrity Engine' is the name KEF gives to its custom DSP implementations. As you'd expect, hardware and software are similar in the LSX and LS50W but, given the price disparity, the LSX uses a less powerful DSP chip. As a result, whereas the LS50W runs at an internal sampling rate of 192kHz at all times, the maximum in the LSX is 96kHz – and this requires a wired connection between the two speakers otherwise it's limited to 48kHz.

The key algorithms in the two speakers perform the same tasks: crossover filtering, bass management and equalisation. Low-pass and high-pass crossover filtering are performed using IIR digital filters, with phase correction using a long FIR filter. While KEF's head of acoustics Jack Oclee-Brown describes the latter as 'relatively textbook', it is tweaked to reduce pre-ringing in the step response to avoid the treble sound becoming glassy. Dynamic bass extension lowers the LF corner frequency at low sound outputs, and adjusts it upwards to protect the driver at higher bass levels. KH