Loudspeakers

Aside from a slight mistermination at 1.2kHz, also visible on the CSD waterfall [Graph 2], the ES-28N’s forward response is flat and even with response errors of a mere ±2.2dB and ±2.1dB, respectively [re. 200Hz-20kHz, see Graph 1]. Pair matching is a supremely tight 0.2dB, albeit with a short-lived deviation to 0.9dB at that discontinuity and at 20kHz. Off-axis uniformity is also excellent, and arguably flatter still [grey trace, Graph 1], so subtle improvements may be realised by toeing the speakers in very slightly. The grille, meanwhile, disrupts the treble above crossover at 2.7kHz, causing a ~7dB dip between 3.6-5.7kHz [blue trace, Graph 1], so is best left detached. Above 20kHz the dual dome breakup modes of the 28mm ceramic-coated alloy dome tweeter are revealed at 30kHz and 42kHz [pink shaded area, Graph 1, and also CSD waterfall, Graph 2].

Distortion is very low indeed at 0.1% from 100Hz-8kHz (re. 90dB SPL/1m), increasing to just 0.3% above 10kHz. Bass is also well judged with the two 180mm woofers maxing out at 100Hz and the down-firing port tuned (very cleanly) to 29Hz, bringing the diffraction-corrected extension down to a quite remarkable 30Hz (–6dB re. 200Hz). The ES-28N is an easy enough drive too, with its impedance modulus held to between 3.6-10ohm (20Hz-20kHz) while the maximum +33/–58° swings in phase angle result in minimum low frequency EPDRs of 1.5ohm/25Hz and 2.0ohm/165Hz. All these features are gained at some expense in sensitivity, however, which is closer to 84.5dB/1kHz (and 84.6dB, 500Hz-8kHz) than the rated 86dB. The ES-28N will soar when partnered with a big amplifier! PM