Loudspeakers

Measuring the Alexia Series 2 in PM's listening room afforded sufficient space to place the measurement microphone at 2.44m (8ft), the shortest distance for which the midrange and tweeter enclosures can be aligned according to Wilson's set-up instructions. The results were corrected by 7.75dB to make them 1m-equivalent, to match our normal measurement distance. The shorter time window, caused by reduced time delay between the direct sound and the floor reflection, reduced frequency resolution to about 400Hz, but concerns about accurate integration of the midrange and tweeter outputs through crossover were allayed.

Wilson claims 89dB sensitivity but we measured a pink noise figure of 90.5dB (0.7dB higher than the original Alexia, 400Hz-20kHz), so the spec. is conservative. This is achieved in part through low impedance: 4ohm nominal is specified, with 2.54ohm minimum at 85Hz, but we measured a dip to 2.4ohm at 88Hz. Impedance phase is quite well controlled but still the EPDR falls to a low of 1.2ohm/67Hz, with further minima at 129Hz (1.8ohm) and 410Hz (1.9ohm). So the Alexia 2 presents a challenging load to the amplifier, albeit not so much as its predecessor (min EPDR 0.9ohm). On-axis frequency responses [Graph 1] at 2.44m display a distinct presence band depression and narrow notch at about 4.3kHz. Because of the latter, response errors are high at ±5.5dB and ±5.2dB but reduce to about ±3.4dB if the notch is ignored. Pair matching over the same 400Hz-20kHz frequency range is first-rate at ±0.6dB. The CSD waterfall [Graph 2] indicates low-treble resonances at 3kHz and 6.4kHz, with two further modes above 10kHz. KH

Sensitivity (SPL/1m/2.83Vrms – Mean/IEC/Music): 91.0dB / 90.5dB / 90.0dB
Impedance modulus min/max (20Hz–20kHz): 2.4ohm @ 88Hz / 11.5ohm @ 46Hz
Impedance phase min/max (20Hz–20kHz): –49° @ 56Hz / 33° @ 593Hz
Pair matching/Response Error (400Hz–20kHz): ±0.6dB / ±5.5dB / ±5.2dB
LF/HF extension (–6dB ref 200Hz/10kHz): 37Hz / >40kHz / >40kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m): 0.2% / 0.8% / 0.4%
Dimensions (HWD): 1347x387x580mm
Price: £64,998