Loudspeakers

The baby of PMC's prodigy range represents a gentle enough load for the partnering amplifier with a mere 5.0ohm minimum occurring at a high 14kHz and swings in impedance phase of –59°/3.0kHz and +40°/1.47kHz contributing to an 'easy' EPDR of 2.3ohm/6.1kHz. However the big upswing in reactive impedance at 2kHz could produce a lift at this frequency when driven by a high source impedance (tube) amp. This aside, the prodigy1's axial response has an uptilted trend [see Graph 1] with a broad boost around 1kHz that lifts its sensitivity to 85.8dB – closer to 84.3dB averaged across 500Hz-8kHz (both figures being lower than PMC's optimistic 87.5dB). Off-axis listening will dial back the treble. Otherwise, the response errors are a high ±4.3dB and ±4.0dB, respectively, but pair matching is an impressively tight 0.7dB if we discount the subjectively irrelevant 1.3dB mismatch around 10kHz. PMC's optional grilles were not supplied for test.

Distortion is low at 0.2-0.5% from 100Hz-10kHz at 90dB SPL, and though a 3rd harmonic dominates through mid and treble any resonances above a few hundred Hz are very well controlled [see CSD waterfall, Graph 2]. However, there are some low freq. reinforcement/cancellation modes visible via the 133mm fibre bass/mid cone – a notch at 150Hz broadly coincides with the peak in output from the 'Laminair' vent at 155Hz while another notch at 245Hz mirrors a port peak at 255Hz. These are also reflected in an additional swing in impedance at 160Hz and 'blips' at 260Hz and up to 660Hz in the impedance/phase traces [see also green shaded area, Graph 1]. The trade-off, for this diddy box, is a respectable 68Hz bass extension. PM