Loudspeakers

Very nearly meeting its rated high 90dB sensitivity, Paradigm's 100F clocked-up a full 89.6dB/1m/2.83V at 1kHz and a slightly lower – but far from low – 89.1dB averaged 500Hz-8kHz. As anticipated, this high sensitivity has been achieved, in part, through a current-hungry nominal 4ohm load where the impedance falls below 8ohm from 68Hz-1.4kHz and as low as 3.2ohm at 119Hz. The biggest swings in phase angle occur through low bass frequencies at –46°/73Hz to +18°/53Hz, –57°/26Hz and +55°/19Hz where the impedance falls to 3.9ohm/38Hz (the helmholtz frequency of the downward-firing port). In practice the output of all three 177mm 'Carbon-X' bass drivers is consistent (56-290Hz re. –6dB) and free of obvious resonance, falling away below 70Hz [green shaded area, Graph 1] where the LF output is augmented by the port to achieve an impressive diffraction-corrected bass extension of 33Hz (–6dB re. 200Hz).

Of course, high sensitivity also brings the opportunity for lower distortion at the 90dB SPL test level, the 100F achieving a low ~0.25% through bass and mid frequencies. The response, measured on the tweeter axis, is very smooth up to 4kHz (±1.7dB) with a lift through the presence and treble thereafter as the 25mm treble dome gets into its stride and the uniformity slackens off to ±4.5dB. Production QC is of a high order, so pair matching is a fine 0.9dB from 200Hz-10kHz (increasing to 2.3dB up to 20kHz). Above 20kHz [pink shaded area, Graph 1] there are two resonances, at 26.9kHz and 43kHz, presumably associated with the 'Al-MAC' tweeter. Lower-level modes at ~4kHz are most likely linked to the 'Al-MAG' mid driver [Waterfall, Graph 2]. PM