KEF R3 Meta Loudspeaker Lab Report

Lab Report

No 'fantasy specifications' here as the most compact of KEF's R Meta series delivers exactly what it says on the tin (ok, website). The 3.2ohm minimum/4ohm nominal impedance rating is met in practice with 3.17ohm at 142Hz although the load is <4ohm from 112Hz-835Hz and the EPDR a moderate 1.65ohm/875Hz. Impedance is 'squeezed' through the bass with a maximum 8.2ohm/35Hz, a (port) dip of 3.5ohm/40Hz and EPDR of 1.78ohm/39Hz, the 'real' impedance peak occurring at a high 2.75kHz. The latter may be sufficient to provide a lift in upper mid response if the R3 Meta is driven with a tube- or other amp with a moderate/high source impedance. Under ideal conditions the R3 Meta offers a very even, fractionally downtilted response [Graph 1] with mere ±1.6dB and ±1.5dB errors (200Hz-20kHz) and superb 0.3dB pair matching, the MAT disc quelling any treble resonances post-2.3kHz crossover [CSD waterfall, Graph 2].

However, as we've seen with Uni-Q in the past, the MAT absorber does not attenuate the +10dB breakup of the 25mm vented alloy dome, here at 39.5kHz [pink shaded area, Graph 1]. Neither does it have any influence over the cancellation notches at 7.3kHz and 15.6kHz on the forward output of the Uni-Q driver through the perforated grille [blue trace, Graph 1]. Otherwise, THD from the 125mm alloy mid cone is 'state-of-the-art' low at ~0.05% (re. 1m/90dB SPL) just as KEF's rated 87dB sensitivity is also spot-on at 1kHz/1m, and only slightly over-optimistic at 86.8dB when averaged across 500Hz-8kHz. Bass extension is good for the limited cabinet volume, its ported 165mm alloy woofer reaching down to 40Hz (–6dB re. 200Hz). PM


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

KEF R3 Meta_Waterfall_40dB_L

Resonances linked to the cabinet and bass unit are minimal while MAT 'eliminates' treble modes

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 87.0dB / 86.8dB / 84.9dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 3.17ohm @ 142Hz, 14.0ohm @ 2.75kHz
Impedance phase: minimum & maximum (20Hz–20kHz) –33° @ 38Hz, +45° @ 1.46kHz
Pair matching/Resp. error (200Hz–20kHz) 0.3dB/ ±1.6dB/±1.5dB
LF/HF extension (–6dB ref 200Hz/10kHz) 40Hz / 51.0kHz/50.3kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.15% / 0.05% / 0.3%
Dimensions (HWD) / Weight (each) 422x200x336mm / 12.4kg
Price £1899 (£649 stands)

GP Acoustics (UK) Ltd
Maidstone, Kent
Supplied by: GP Acoustics (UK) Ltd
01622 672 261