System Audio Legend 7.2 Loudspeaker Lab Report

Lab Report

With the speaker arranged in 'landscape' guise, and measured on the tweeter axis, its forward response shows a boosted presence and high treble [Graph 1], the trend giving high response errors of ±4.8dB and ±5.0dB but with a tight 1.2dB pair matching (200Hz-20kHz). The two 130mm pulp bass/mid drivers are tuned quite sharply to a high 130Hz while on-wall boundary reinforcement results in a limited boost to LF output [green shaded area, and boxout p67] and a bass extension of 75Hz (–6dB re. 200Hz). There's also some lobing out to ~600Hz [blue trace] although, measured freefield, the response is smoother and the diffraction-corrected bass extension only slightly diminished at 85Hz. Also, resonances seen in the CSD waterfall [Graph 2] from 2kHz-5kHz are exaggerated by on-wall mounting but that, of course, is the designated habitat for the Legend 7.2.

Switching the cabinet through 90° and measuring on the same axis produces a response that matches within ±0.5dB [grey trace] including the +9dB treble peak at 19kHz (re. 1kHz). The midband depression also yields a lower 86.2dB/1kHz sensitivity than SA's claimed 89dB, although this improves to 87.1dB across 500Hz-8kHz, so the Legend 7.2 will develop higher SPLs with modestly-powered amps than the 1kHz figure might suggest. Furthermore, distortion, at ~0.1% (re. 90dB SPL) remains usefully low across the midrange. Finally, while SA offers a loose '4-8ohm' spec. for the Legend 7.2, in reality impedance drops to a low of 3.3ohm/155Hz and remains sub-3.9ohm at 20Hz and 20kHz.The 'toughest' load appears near the 2.5kHz crossover where a 6.8ohm impedance is married to a –54° phase angle. PM


Response inc. nearfield drivers [green], corrected to 1m at 2.83V [yellow], ultrasonic [pink]. Left, black; right, red; vertical [grey]; on wall [blue]


Treble is 'clean' but there are multiple low-level modes associated with the bass/mid drivers

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 86.2dB / 87.1dB / 85.8dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 3.28ohm @ 155Hz, 31.5ohm @ 95Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –59° @ 1.82kHz, +52° @ 505Hz
Pair matching/Resp. error (200Hz–20kHz) 1.2dB/ ±4.9dB/±5.0dB
LF/HF extension (–6dB ref 200Hz/10kHz) 75Hz / 38.2kHz/50.4kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 1.2% / 0.11% / 0.35%
Dimensions (HWD) / Weight (each) 470x286x154mm / 9.3kg
Price £2100

System Audio A/S
Supplied by: Karma-AV Ltd, York
01423 358846