Acoustic Energy Corinium loudspeaker Lab Report

The design of all speakers, and especially compact floorstanders, is typically a trade off between response uniformity, ease of drive, bass extension and sensitivity. The Corinium's priorities are clear: a very flat forward response trend [see Graph 1] with mere +2.3dB and +2.9dB errors (re. 200Hz-20kHz), respectively, and a high 90.6dB/1kHz (re. 2.83V/1m) sensitivity, all traded for a modest 52Hz corrected bass extension (–6dB re. 200Hz) and a pretty tough amplifier load. The minimum here is 2.6ohm/113Hz, staying below 4ohm from 90Hz-1kHz, but it's the –68°/+40° swings in impedance phase through the bass that deliver the gut punch to your amplifier – dips in EPDR to 2ohm right through the bass (20Hz-130Hz) with a minimum of 0.96ohm/91Hz.

The damped-MDF cabinet is impressively inert [CSD waterfall, Graph 2] while the minor resonance at 1.1kHz is associated with a mid-cone mistermination [see also Graph 1]. The other notch at 6.4kHz is deflated as the speakers are toed slightly off axis [±15°, blue trace], even if this 'flatter' mid/presence is traded for a progressive loss in very high treble (–4dB/20kHz re. 10kHz). Fine-tuning of speaker angle will influence the perceived 'air' of this speaker. The magnetically attached grille, despite its low profile, introduces a 2.5dB dip through the mid/treble crossover region [grey] but pair matching remains a very tight 0.35dB up to the same crossover point, widening only to 0.85dB between 6kHz-20kHz. The two woofers have a slightly 'peaky' 96Hz bass alignment but the port tuning is deliberately set low at 27Hz [see boxout], with cabinet/pipe modes at 160Hz, 290Hz and 775Hz also escaping at a reduced –13dB (re. 200Hz). PM

ABOVE: Resp. inc. nearfield summed drivers/port [green], freefield corrected to 1m at 2.83V [yellow], ultrasonic [pink]. L, blk; R, red; ±15°, blue; grille, grey

ABOVE: Cabinet modes are well damped, exposing a mild cone mistermination at 1.1kHz [see also Graph 1]

Hi-Fi News Measured Specifications:

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 90.6dB / 90.8dB / 89.2dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 2.55ohm @ 113Hz
18.1ohm @ 62Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –68° @ 70Hz
+39° @ 52Hz
Pair matching/Resp. error (200Hz–20kHz) 0.85dB/ ±2.3dB/±2.9dB
LF/HF extension (–6dB ref 200Hz/10kHz) 52Hz / 34.6kHz/35.0kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.15% / 0.4% / 0.35%
Dimensions (HWD) / Weight (each) 1100x315x385mm / 40kg
COMPANY INFO
Acoustic Energy Loudspeakers Ltd
Gloucestershire, UK
Supplied by: Acoustic Energy Loudspeakers Ltd
Telephone: 01285 654432
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