B&W 801 D4 Signature Loudspeaker Lab Report

Lab Report

With the same raw specification as the 801 D4, the Signature version also meets its rated 90dB sensitivity at 89.7dB (1kHz and 500Hz-8kHz). The characteristic 'three hump' forward response trend retains its –2dB 'step down' between 200Hz-1kHz and 3dB dip at 600Hz [see Graph 1, below], resulting in errors of ±3.7dB and ±3.9dB, respectively, from 200Hz-20kHz, or ±2.6dB over a narrower 800Hz-20kHz. However, pair matching is a far tighter 0.6dB so this response shape is clearly engineered and intentional. Otherwise the mid/treble response is broadly 'flat' while the Diamond dome provides exceptional ultrasonic extension [pink shaded area, Graph 1] out to 75kHz (–6dB re. 10kHz). There is no need for an aftermarket 'super tweeter' with the 801 D4! The magnetically attached grilles offer precious little disruption [blue trace, Graph 1] with a maximum loss of just 0.9dB between 1-2kHz posing almost no subjective impact.

Distortion remains fabulously low through mid frequencies at ~0.05% (re. 90dB SPL at 1m) but is now also very low at bass frequencies at ~0.15% from 50Hz-200Hz at the same output level. As discussed, the Signature's port and woofer bandpass tuning is shifted slightly upwards, but the diffraction-corrected bass extension of 27Hz (–6dB re. 200Hz) is still very impressive and subject to 'in room' boost depending on how the speakers are postioned with respect to walls and corners. The combination of high sensitivity, low distortion and deep bass comes at the expense of a taxing amplifier load, for while the 3.37ohm/91Hz minimum is still 'easier' than B&W's 3.0ohm specification, the EPDR dips to a low of 1.2ohm/69Hz. PM


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

B&W 801 D4 Sig_Waterfall_R_35dB_4msec

Aside from a slight mode at 1.3kHz (coincident with a peak in response), resonances are swiftly quelled

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 89.7dB / 89.7dB / 87.9dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 3.4ohm @ 93Hz, 28.1ohm @ 41Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –72.5° @ 48Hz, +43.7° @ 1.38kHz
Pair matching/Resp. error (200Hz–20kHz) 0.6dB/ ±4.0dB/±3.7dB
LF/HF extension (–6dB ref 200Hz/10kHz) 27Hz / 74.0kHz/75.1kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.15% / 0.05% / 0.65%
Dimensions (HWD) / Weight (each) 1221x451x600mm/101kg
Price £45,000

B&W Group Ltd
West Sussex
Supplied by: B&W Group Ltd
0800 232 1513