Loudspeakers

Rockport’s 32mm beryllium dome has its principal breakup just outside the audioband at 23.9kHz [pink shaded area, Graph 1, and CSD waterfall, Graph 2] although the peak here is not preceeded by the (typical) notch in output. Instead, the Orion’s treble output is very flat with only a slight depression at 6-7kHz. Rockport recommends toeing the speakers out slightly, crossing behind the listener’s head, and the ±15° off-axis response [grey trace] shows why – the Orion delivers an exceptionally flat response here (within ±1.6dB, 200Hz-20kHz). Such a uniform amplitude response is rare from a passive, DSP-free speaker system, though the pair matching between the 178mm midrange driver(s) could be improved from the 1.2dB seen here [black/red traces, Graph 1]. This accounts for the difference in the still modest ±2.6dB and ±3.4dB response errors, respectively, though, in all instances, the grille brings a 3.5dB dip between 5-6kHz [blue trace].

Sensitivity is generous, meeting the Orion’s specification at 90.3dB/1kHz while distortion holds to within 0.25-0.7% at this same level (100Hz-10kHz). The port, meanwhile, is very broadly tuned from 15Hz-53Hz (–6dB, peaking at 23Hz) and, despite showing minor modes at 106Hz and 495Hz, brings the corrected system bass response down to 30Hz (–6dB re. 200Hz). However, payback comes in a punishing amplifier load! Phase angles are held to within ±45° through the audioband but dip still further to –66°/15Hz, and with impedance minima of 2ohm/52Hz and 2.34ohm/23Hz, the EPDR drops to 0.8ohm/20Hz and 1ohm/45Hz, with long stretches of sub-2ohm up to 1kHz. PM

Hi-Fi News Measured Specifications:

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC)	90.4dB / 89.7dB / 88.3dB
Impedance modulus: minimum & maximum (20Hz–20kHz)	2.02ohm @ 52Hz 15.4ohm @ 3.6kHz
Impedance phase: minimum & maximum (20Hz–20kHz)	–45° @ 20Hz +43° @ 785Hz
Pair matching/Resp. error (200Hz–20kHz)	1.2dB / ±2.6dB / ±3.4dB
LF/HF extension (–6dB ref 200Hz/10kHz)	30Hz / 35.7kHz / 38.8kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m)	0.25% / 0.45% / 0.7%
Dimensions (HWD) / Weight (each)	1278x516x671mm / 163kg