Stand Loudspeaker Reviews

Back in June 1994, I reviewed the Bowers & Wilkins John Bowers Silver Signature standmounted loudspeaker. This speaker cost a breathtaking $8000/pair at that time, and I subsequently bought the review samples and their matching slate stands. It was the best-sounding speaker I had used in my Santa Fe listening room: When the company's then-owner, Robert Trunz, visited me a couple of years later, he told me that he hadn't realized how good the Silver Signatures could sound. But after I moved to Brooklyn, in 2000, the Silver Signature never worked as well in my new listening room. I still own the speakers, but they currently live in our storage unit.

In February 2004, I reviewed the Series 1 B&W 705 loudspeaker. I was impressed by this affordable two-way standmount, writing, "The 705 might not have enough bass or go loud enough for those wanting affordable full-range performance, but within its limitations, the new B&W is an astonishingly good loudspeaker. It offers clean, grain-free, uncolored sound for just $1500/pair. You'd have to spend a lot more to get significantly more quality."

That original 705 was replaced in 2017 by the 705 Series 2, which cost $2999/pair. To my regret, I missed out on reviewing that version (footnote 1). When I learned that Bowers & Wilkins was introducing an optimized version of the 705 S2, called the 705 Signature and priced a penny less than $4000/pair without the matching stands, I asked for review samples.

The 705 Signature
Other than being a two-way, reflex-loaded standmount, the 705 Series 2, which remains in B&W's lineup, is a very different loudspeaker from the 2004 version. The original tweeter's aluminum-alloy dome was replaced with a dome formed by vapor-depositing a layer of carbon on a 30µm-thick aluminum diaphragm, reinforced by a profiled peripheral ring of 300µm-thick carbon attached to its rear. This stiffens the diaphragm and endows it with greater resistance to bending, allowing it to operate with perfect pistonic motion up to a frequency well above the audioband. The first breakup point is stated to be at 47kHz. The S2 tweeter's motor is derived from the one used in B&W's 800 D3 line; it has a vented pole-piece so that the backwave can be absorbed within a bullet-shaped enclosure machined from a solid aluminum billet. That billet, which is mounted on top of the woofer enclosure with a compliant support, weighs more than 1kg and also acts as a heatsink for the drive-unit.

The 705 S2 woofer replaced the original's woven-Kevlar cone with a cone formed from Bowers & Wilkins's proprietary, silvery, woven Continuum material, which they make themselves in the UK. The ideal material for a speaker diaphragm is very light, very stiff, and has very high self-damping. Continuum is said to get close to that ideal—in particular, it has better self-damping than the Kevlar cone that B&W used in Series 1. Self-damping helps the cone avoid the abrupt transition from pistonic behavior to break-up mode. It also means that waves propagate through the cone material less easily and reflect less readily from the surrounds, so the standing waves formed in the cone are reduced in level—less self-noise, as it were.

The same unit is used in the Signature model, reflex-loaded with B&W's flared "Flowport" on the rear panel, where small dimples reduce turbulent air noise. The same tweeter is also used.

The new Signature version features an optimized crossover to get the most performance from the drive-units inherited from the 705 S2, including specially treated and upgraded bypass capacitors sourced from Mundorf. Electrical connection is via two pairs of binding posts, with jumpers for single wiring.

The 705 Signature's enclosure features what B&W calls a Datuk Gloss finish. This ebony-colored, sustainably sourced veneer, supplied by specialty Italian wood company Alpi, has nine coats of finish applied, including primer, base coat, and lacquer. Further emphasizing the elegant appearance, the woofer has a bright metal trim ring, and there is a Signature identity plate on the rear panel.

Setup
Setting up the 705 Signatures came as a relief after dealing with the enormous, 330lb Göbel Divin Marquises I reviewed in the October 2020 issue. After removing the plastic-foam spacer that supports the tweeter housing for shipping, I sat the 705 Signatures on the 24"-high Celestion stands I use for bookshelf speakers. (The central pillars of these stands are loaded/damped with a mix of birdshot and dry sand.) I placed the B&Ws where the small KEF LS50s have worked best in my slightly asymmetrical room. After some experimenting with positioning, the woofer of the left-hand 705 Signature ended up 36" from the LPs that line the nearest sidewall and the right-hand speaker's woofer was 45" from the bookshelves that line its sidewall. Both woofers were 76" from the wall behind them. With the speakers' ports open, this gave the best transition between the lower midrange and upper bass. The 705 Signatures were toed-in to the listening position, and I didn't use the vestigial woofer grilles, preferring the appearance without them.

Once I had finalized the positions of the Bowers & Wilkins 705 Signatures, I started my serious listening, driving the speakers with the Parasound Halo JC 1+ monoblocks I reviewed in the June 2020 issue.

Listening
The dual-mono pink noise track on my Editor's Choice CD (Stereophile STPH016-2) sounded evenly balanced, uncolored, and smooth when I sat with my ears just below the 705 Signatures' tweeters, which were 39" from the floor. The image of the pink noise was narrow and stable, with no "splashing" to the sides at any frequency. If I sat upright so that I was level with the tweeters, the treble started to sound a little accentuated, and the balance sounded hollow if I stood up.

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Footnote 1: Kal Rubinson reviewed the floor-standing 702 S2 in May 2018.