Loudspeakers

Compared with the Electra Amator III [HFN Jul '19], the Maxima's more complex third-order crossover (down from 2.5kHz to 2.1kHz) and increased cabinet volume bring improved bass extension and ease-of-drive for a slightly reduced 87dB (200Hz20kHz) or 85.5dB (500Hz-8kHz) sensitivity. The Maxima is still a nominal 4ohm load, but its minima are higher at 4.0ohm/16.5kHz, 4.05ohm/142Hz and 4.5ohm/38Hz, while phase angles are 53°/55Hz and –62°/70Hz. So it's only moderately challenging!

These impedance and phase spectra also reveal a mild inflection at the ~2kHz crossover, seen as a reinforcement in the forward response [black/red traces, Graph 1] and as a dominant mode in the CSD waterfall [Graph 2] – possibly a mistermination between the pulp bass/mid cone and its rubber surround. THD also rises slightly from the low ~0.4% achieved through bass and treble to 0.5-0.6% at this same 1-5kHz (re. 90dB SPL at 1m). Otherwise, the Amator Maxima's response trend is flat to within ±2.0dB prior to a +5dB lift above 5kHz (measured on Sonus faber's reference axis above the treble dome). Toeing the speakers a little off-axis will likely bring the mid and treble into balance at ~3m listening distances. Pair matching is superb at 1.0dB (200Hz-20kHz) while the small magnetically-attached grille has little adverse impact [blue trace, Graph 1].

The pulp bass/mid driver has a usefully wide 52-440Hz/–6dB bandwidth while diffraction-corrected nearfield measurement shows this combines with the higher-Q 35Hz output of the rear port (albeit with spurious modes at 240Hz and 780Hz) to deliver a generous 37Hz (–6dB re. 200Hz) bass extension. PM