B&W 805 D4 Loudspeaker Lab Report

Lab Report

B&W's most compact D4 model shares its 25mm Diamond Dome tweeter, set within the tapered and recently elongated 'solid body on top', with the flagship 801 D4 [HFN Nov '21]. This rigid and lightweight dome has a very extended HF response, reaching out to 61kHz (–6dB re. 10kHz), with well-managed breakup modes at 46kHz and 70kHz [pink shaded area, Graph 1 and Waterfall, Graph 2]. Measured on this tweeter's axis, the 805 D4 shows a 'brightened' treble that lifts some +6dB above the mean midband level at 10kHz, the dished response causing sensitivity to fall short of B&W's rated 88dB. In practice, 86.2dB (500Hz-8kHz) is more realistic while the 1kHz spot figure is lower still at 83.8dB. Response uniformity is below average at ±4.4dB but the L/R pair matching is superb at 0.75dB (200Hz-20kHz).

The 165mm Continuum bass/mid driver operates over an 82-400Hz bandwidth (–6dB, re. 145Hz) with nearfield analysis revealing a more erratic output >800Hz and a broad peak at 1.3kHz, also visible as a mode on the CSD plot [Graph 2], the forward response [Graph 1] and via the port. The latter is tuned to 41Hz, offering a broad 26Hz-97Hz output that brings the 805 D4's corrected LF extension down to a very respectable 39Hz (–6dB re. 200Hz). Again, what may be cabinet standing waves are seen at 330Hz (–11dB), 700Hz (–14dB) and 1.3kHz (–19dB). The largest swings in impedance and ±57° phase also occur through the bass, the toughest – though not especially 'tough' – being at 145Hz (5.1ohm/–26o) just before the 4.65ohm/187Hz minimum. So what the 805 D4 lacks in sensitivity it recovers in good bass extension and ease-of-drive. 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


One mistermination/cone mode is visible at 1.3kHz with very mild treble resonances at 8-14kHz

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 83.8dB / 86.2dB / 84.8dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 4.65ohm @ 187Hz, 50.1ohm @ 79Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –58° @ 91Hz, +57° @ 23Hz
Pair matching/Resp. error (200Hz–20kHz) 0.75dB/ ±4.5dB/±4.4dB
LF/HF extension (–6dB ref 200Hz/10kHz) 39Hz / 62.0kHz/61.4kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.18% / 0.1% / 0.45%
Dimensions (HWD) / Weight (each) 440x240x373mm / 15.6kg
Price £6250 (stands, £1100)

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