Loudspeakers

One glance at the Element 3’s minimally reactive (±8° phase angle) 15-22ohm load (20Hz-40kHz), with its mere 12.3ohm/2.2kHz EPDR, suggests this is no ordinary ‘passive’ speaker. The massive 101dB sensitivity (re. 2.83V/1kHz/1m) is also unheard of for a horn-free loudspeaker, but then this particular Sphinx is a unique proposition [see boxout]. Importantly, the uniformity of its load means that the system response will remain largely unchanged, even when driven by high output impedance tube amps, although the ‘colour’ of your amp will still be carried through. (The speaker shows a higher 0.5% THD through the midrange than bass or treble.) Tested between its mid and HF drivers, the Sphinx Element 3 offers a very flat output from 800Hz-3kHz [see Graph 1] and with very respectable ±2.5dB and ±2.0dB response errors either side (re. 200Hz-20kHz). Pair matching is a very tight 0.4dB (200Hz-15kHz) with a more relaxed, and subjectively inconsequential, 1.1dB at 18kHz. The 20mm soft dome tweeter declines very slightly in the presence region but picks up again above 10kHz to deliver a strong high treble, reaching out to a very extended 46kHz (–6dB re. 10kHz).

The Element 3’s lower mid/bass response includes some unusual ripples but is otherwise artfully engineered. The 150mm ‘woofer’ peaks at 75Hz, with a –2.2dB cut when switched from ‘+3dB’ to ‘Neutral’ [blue trace], while the exit of the tapered transmission line reveals a low 29Hz tuning with a 24-60Hz (–6dB) bandpass. The output is free of obvious cabinet and other spurious modes and contributes to a (quite remarkable) diffraction-corrected bass extension of 32Hz. PM