Loudspeakers

Sensitivity is a little below ELAC’s 88dB spec. at 87.5dB (re. 1kHz/ 2.83V/1m) while the axial response with its declining midrange/presence [Graph 1] brings the broadband (500Hz-8kHz) figure down still further to 86.5dB. Above 12kHz there’s a startling 7dB recovery in treble output yielding a final extension of 55kHz (–6dB re. 10kHz), but this switchback trend also pushes response errors up to ±4.2dB and ±4.0dB, respectively (re. 200Hz-20kHz). ELAC’s directivity control [see boxout] has little impact on its axial response, as expected [red trace], but toeing the speakers in by 15° and then selecting ‘spacious’ [L position for L speaker, and R for R, respectively; blue trace] delivers a smoother overall mid/presence response than is achieved when the M 807s are pointing directly at the listener. Response errors shrink to ±3.7dB and ±3.6dB, respectively, in this configuration. Shifting the directivity control in the opposite direction [R position for L speaker, and L for R, respectively; green trace] brings increased ±5.6dB/±5.7dB response errors.

The large down-firing port, tuned to a low 28Hz, has a broad output (18-80Hz) that supplements the 30-170Hz bandpass of the woofers (all re. –6dB) to deliver a deep, diffraction-corrected bass extension of 23Hz. This impressive result is not wholly ‘amp friendly’, however, as ELAC’s 3.1ohm/350Hz min. impedance slightly underestimates the 2.9ohm/375Hz measured here. In practice the impedance is sub-8ohm from 20Hz-5kHz and while phase angles are a modest –43°/+25°, the former occurs in the bass, creating a 1.5ohm/24Hz EPDR. Aside from a 5ohm ‘peak’ at 150Hz, the EPDR is sub-3ohm from 20Hz-4.5kHz. PM