MoFi SourcePoint 10 Loudspeaker Lab Report

Lab Report

In addition to all else that a two-way, coincident driver array might offer, MoFi's Andrew Jones has also set his sights on another engineering goal – good sensitivity and bass extension combined with a benign amplifier load. The SourcePoint 10 meets its 8ohm nominal/6.4ohm minimum rating with a dip to just 6.35ohm/165Hz and despite the high +50° phase angle from 530Hz-1.37kHz the minimum 2.9ohm EPDR (equivalent peak dissipation resistance) occurs at a lower 101Hz and 425Hz. This will not prove especially troublesome, but while the SourcePoint 10 is inherently 'tube amp friendly', the big rise in impedance to 86ohm/1.7kHz may still result in an emphasis in upper mid (vocal) response depending on the magnitude of the partnering amplifier's source impedance.

Otherwise, the SourcePoint 10's axial response is essentially flat in trend [Graph 1] albeit with a series of 'ripples' contributing to a modest ±2.3dB response error (increasing to ±4.7dB and ±4.4dB, respectively, once the 20kHz tweeter peak is taken into account). However, the plastic-framed grille exaggerates these reinforcement/cancellation modes [blue trace, Graph 1] and should be removed for 'serious' listening. Sensitivity is just shy of MoFi's generous 91dB spec. at 90.4dB/1kHz and 90.5dB/500Hz-8kHz while the pair-matching is acceptable at 0.95dB. Distortion is a low <0.1% through the midrange (re. 90dB/1m) increasing to ~0.5% at bass frequencies where the broad 60Hz-1.4kHz/–6dB bandwidth of the 250mm pulp-coned woofer is augmented by the clean 46Hz tuning of the two rear-facing ports to deliver a respectable 47Hz extension (–6dB re. 200Hz). PM


Response inc. nearfield summed driver/ports [green], freefield corrected to 1m at 2.83V [yellow], ultrasonic [pink]. Left, black; right, red; w. grille, blue

MoFi SourcePoint 10_Waterfall_L_35dB

There's a minor cabinet mode at 315Hz with broader modes from the large pulp cone >500Hz

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 90.4dB / 90.5dB / 89.2dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 6.35ohm @ 165Hz, 85.8ohm @ 1.7kHz
Impedance phase: minimum & maximum (20Hz–20kHz) –53° @ 2.6kHz, +53° @ 700Hz
Pair matching/Resp. error (200Hz–20kHz) 0.95dB / ±4.7dB/±4.4dB
LF/HF extension (–6dB ref 200Hz/10kHz) 47Hz / 33.5kHz/34.0kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.5% / 0.07% / 1.0%
Dimensions (HWD) / Weight (each) 572x368x422mm / 21kg
Price £4500 (£550 stands)

MoFi Electronics
Chicago, USA
Supplied by: Karma-AV Ltd, York
01423 358846