B&W 705 loudspeaker
"There was a time when everyone thought that the loudspeaker was the weakest link in the reproducing chain," wrote JG (footnote 2). "This tag must be forgotten, for this enclosure with its high sensitivity, wide and smooth frequency response, brilliant transient reproduction, and broad and balanced polar response, is approaching the ideal which everyone is seeking—perfection."
Perfection in a loudspeaker? That goal is as elusive in the 21st century as it was in the second half of the 20th. But in the years since the P2 was introduced, the Bowers & Wilkins Electronics company (always a separate business entity from the store) morphed into what has since become one of the world's leading speaker marques, B&W Loudspeakers. John Bowers passed away in late 1987 and his partner, Robert Trunz, sold the company to Canadian conglomerate Equity International in the mid-1990s. B&W now has two factories and a dedicated R&D facility in the UK, and a cabinet-assembly plant in Denmark.
B&W these days refers to itself as "B&W Bowers & Wilkins," perhaps in an attempt to recapture the ambiance of its formative days. But its loudspeaker engineering is bang up to date. When I heard about the company's new 700 series of speakers, based on the technology featured in their cost-no-object Nautilus series but priced to sell in the real world, I asked to review the $1500/pair 705.
...replaces B&W's CDM 1NT and is a moderately sized two-way, stand-mounted design. Both drive-units are made in-house. The woofer features B&W's familiar yellow cone of woven Kevlar and is reflex-loaded by a large port immediately beneath it on the front baffle. This has flares on both inner and outer openings, with its surface dimpled to reduce turbulence. The 1" dome tweeter is mounted in a minimal enclosure on the top of the cabinet, which optimizes dispersion. Both drive-units have had a lot of attention paid to minimizing distortion, both through careful design of their magnetic circuits and the use of such things as copper covers and shorting rings on the pole-pieces. In addition, the tweeter has a lower inductance than usual, achieved by use of single-layer ribbon for the voice-coil, to allow its response to be extended well above the audioband. The tweeter dome is also acoustically loaded by the transmission-line tube first seen in the Nautilus models.
The 705's cabinet looks refreshingly different. Its front baffle and top plate are formed from a single piece of multi-ply wood, this curving back above the woofer to meet the rear panel. The sidewalls are lined with foam and are not quite parallel; the 705's front is slightly wider than its back, which reduces the effect of internal standing waves. There is an internal vertical brace as well as a fiber filling.
Electrical connection is via two pairs of binding posts on the rear panel. These have large holes and sliding sleeves to allow spade lugs to be securely clamped. The crossover is mounted to a circuit board fastened to the inside of the terminal panel. Fairly minimal in topology, it features two air-core inductors, two plastic-film capacitors, and two resistors.
Though B&W makes a matching stand for the 705 (the FS700), this wasn't supplied for review. I therefore sat the speakers on 24" Celestion Si stands, their central pillars filled with a mix of lead shot and sand. I found the speaker not too fussy about the exact listening axis, but listening with my ears on the tweeter axis gave the best top-octave extension. The speakers were placed well away from room boundaries and toed-in to the listening seat. I removed the grilles from the woofers; though I first left the minimal grille covers over the tweeters, I ended up preferring the sound without them. I used the speakers reflex-loaded, finding their sound too lightweight when the ports were blocked with the foam inserts.
Footnote 1: As I wrote these words, I heard the sad news that Quad's Peter Walker has passed away, at the age of 87. You can read my appreciation of PW's work here.—John Atkinson
Footnote 2: The late John Gilbert was one of the most extraordinary characters I have been privileged to knock back a beer with. John may have had an encyclopedic knowledge of all things audio, but he was also a daredevil. I remember being scared silly by a roller-coaster with a 180 degrees vertical half-loop at the 1985 Munich Beer Festival; while the rest of us youthful audio scribes were kissing the ground, we witnessed then-octogenarian John standing in line first for a second ride, then for a third.—John Atkinson