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Lab measurement of the new crossovers

Impedance

The impedance curve shows the difference between the original 11ohm KEF xover and the new cicable xover. – It is obvious that the response is smoother especially in the area where the units cross.

Third order harmonics [K3]

As explained before third harmonics are dominant. The above measurement shows third harmonic distortions over frequency only for both xovers the original KEF and the cicable. The result is nearly a 100% improvement because of an average reduction of –50dB!

Intermodulation distortions

How great the improvement is becomes obvious by looking for the spectrum of the intermodulation distortion, – here for the two frequencies of 100Hz and 2kHz in the low frequency path. Density and quantity of the sideband distortions especially of the third harmonics lets one imagine how much the audible »detail« improvements will be especially in the mid–band. The average improvement of intermod distortion is about 45dB !!

Harmonic distortions :: KEF 11ohm

The measurements showing the spectral distortions for three frequencies: 100 Hz, 1kHz and 3kHz which are filtered out by a notch filter. The rest you can see consist of harmonics, noise and intermodulation artefacts which are not harmonically related to the input frequencies [100Hz, 1k, 3k]. Most obvious are odd harmonics [k3, k5, k7 and so on], with the third harmonic [k3] dominant at 0.1% which equals to –60dB. Please note that the measurements were taken with at a level equal to about 30Watts@8ohm, a very practical value.

Harmonic distortions :: cicable for 11ohm – version

As before, the measurements show the spectral harmonic distortions via the cicable xover. The spectrum at the output of the xover is about 40dB lower [third harmonics]. All other distortions are even further down! and are almost completely masked by the noise of the test amplifier.

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