Bowers & Wilkins SEVENTH HEAVEN 700 User Manual

SEVENTH HEAVEN

B&W’s new 700-series neatly fills the gap between its ‘budget’ 600s and upmarket Nautilus 800s

PRODUCT B&W 703

TYPE 3-way floorstanding loudspeaker

PRICE £2,000

KEY FEATURES Size (WxHxD): 23x101x36cm

Tube-loaded alloy dome tweeter P165mm Kevlar

midrange driver P2x 165mm paper/Kevlar bass drivers

CONTACT  01903 221500 q www.bwspeakers.com

he largest of all the specialist hi-fi speaker brands, Worthing-based B&W is noteworthy for the considerable

resources it devotes to research and development, with a small army of engineers operating out of a well-equipped, purposebuilt facility some miles away from the main factory in Steyning.

It’s this research effort that lay behind the very advanced and radical Nautilus 800 models in 1998, and their subsequent Signature upgrades, and something of the same has now ‘trickled down’ to the brand new 700-series models, which very much fill a gap between the 800s and their ‘budget’ 600-series brethren.

There are three 700s all told: an £800 per pair 705 standmount; a £1,300 per pair 704 two-and-a-half-way floorstander; and this £2,000 three-way 703 floorstander, which arrived just a couple of weeks too late for inclusion in this month’s group test.

In a sense, these 700s replace the CDM NT models, though perhaps supplant is the better word, as they by no means fit into the same price slots and are claimed to deliver much more of a mid-point level of performance between the widely separated 600s and 800s than their predecessors.

The industrial design brief here was to make reference to the cabinet shape of the outgoing CDM NT series – specifically the concept of mounting an external tweeter on top of a sloping cabinet top – but also to incorporate the bent-wood technology that was pioneered in the Nautilus 800s. A further requirement was to reduce the rather angular appearance of the CDM NTs, and also to take acoustic factors into account.

The new speaker looks less fussy than its predecessor, with cleaner lines and construction that promises some performance advantages. The front and top are formed from a single piece, giving great strength, while the curve under the top-mounted tweeter will give greater ‘scatter’ than the flat surface used before. The radiused edges have disappeared now, but the enclosure is subtly tapered front to rear, so the only parallel

surfaces are the front and back, which will help to de-focus the internal standing waves. Classy real-wood veneer covers all the faces, our samples coming in an attractive American walnut.

Crucially, this 703 uses a version of the ‘surroundless’ FST (Fixed Suspension Transducer) midrange driver that was

HI-FI CHOICE november2003

B&W 703 loudspeaker

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pioneered by the more upmarket Nautilus models, and which provides one of the better reasons for adopting the extra complexity of a three-way, as distinct from the two-and-a-halfway configuration used in the 704.

In the vast majority of three-ways, the midrange driver is either the same as, or a scaled down version of, the bass driver. However, the essential difference between a midrange-only unit and any unit required to produce bass (whether bass-only or bass/mid) is that a mid-only driver doesn’t undergo significant cone excursion.

Whereas the rubber roll surround at the edge of a driver cone normally has to centre the cone, absorb edge-of-cone vibration and permit generous fore ’n’ aft excursion, a midonly driver has no need for the last of these. B&W has therefore come up with a midrange driver with a heavy but unfixed surround that locates the cone but ignores excursion in order to optimise the vibration absorption characteristics, by using a heavy rubber gasket in place of the usual roll. The result, allegedly, is improvement in dynamic range resolution.

Thanks to relatively new Klippel distortion measuring apparatus, all the drive units have undergone significant improvements over their predecessors. B&W calls the techniques it has used to make the drive unit magnetic fields more symmetrical and minimise variations in inductance ‘balanced drive’. The high frequency extension of the external tube-loaded tweeter has also been improved, avoiding any need for a ‘super-tweeter’.

There are two bass drivers here, port-loaded and operating in tandem, and each with

“The 703 is much less laid back than the Signature, and actually sounds much more upfront than any B&W in recent memory.”

Kevlar-reinforced paper cones 120mm in diameter. The FST midrange has B&W’s familiar yellow woven Kevlar cone, 140mm in diameter, while the tweeter has a 25mm alloy dome. Just two pairs of terminals are fitted, conveniently low down near the floor.

SOUND QUALITY

Not unexpectedly, in-room measurements pointed towards free-space siting for this substantial floorstander, though the bass alignment is relatively dry and bungs are provided should close-to-wall siting be unavoidable for domestic reasons.

First impressions came as a bit of a surprise, especially as the Signature 805 (see p62) was on site at the time of its arrival, allowing immediate comparisons. The 703 is certainly much less laid back than the baby Signature, and actually sounds much more upfront than any B&W in recent memory.

Indeed, the initial judgement was that this speaker was a little too bright and edgy for its own good, with a touch of aggression and harshness that bordered on the unacceptable. This opinion was reinforced by the visible peak at around 4.5kHz, near the bottom end of the tweeter’s operating range, which was clearly visible on the far-field in-room traces.

While this treble strength did seem likely to

MULTICHANNEL OPTIONS

B&W makes centre and surround speakers to fit in-between and around the 703/4/5 stereo pairs for multichannel sound. The £450 HTM7 (for ‘Home Theater Monitor’) is the centre-front. Retaining the cur ved top and external tweeter, this two-way appears bulky, but voice-matches the 703 well enough, albeit without the latter’s slightly bright top end. (It matches the 704 even better – probably because it shares the same drivers.) One crucial thing to note – the HTM7 should not be placed on top of a large-screen TV set, as close proximity to a large flat surface adds a ‘honky’, thickening coloration in the midband. Coming soon, the £900 per pair DS7 surround speaker looks potentially even more interesting. It’s switchable between dipole and monopole modes (the former best for movies, the latter for music), and the change can cleverly be effected remotely via a 12V ‘trigger’ signal from the receiver.

pose a problem at first, after a few days the tendency towards harshness and aggression seemed to have mollified quite significantly. Our samples had apparently had a couple of days of running in before being shipped, but presumably this is a speaker that needs at least a week to get properly settled down.

november 2003 HI-FI CHOICE

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