Originally printed in the March 1995 issue of Gramophone.

New models from B&W have been few and far between in the last few years. This doesn't mean that the design team at the Steyning Research Centre has been idle, but rather that it has seemed politic to put effort into producing Mk II and in some cases Mk III versions of some existing, widely accepted and popular models, both lowly and exotic. There are often many reasons for this approach; for example, new developments may suggest real improvement in sound quality, new materials may offer production advantages and new techniques may assist in holding prices against rising costs. To be sure, in the interim there have been several attention-grabbing eccentricities to be seen at exhibitions and audio shows—the valveless pseudo-saxophone looking design of a few years back and recently an indescribable something resembling an unhappy conjunction of TV's "Mr Blobby" and a blue-with-cold Michelin Man. And then of course, there is Nautilus, a giant snail of a loudspeaker, though this is certainly no eccentricity — rather it is a true example of form following design; a very serious loudspeaker costing very serious money.

Everyone who entered the inspired jungle setting of B&W's stand at last September's Live '94 exhibition soon realised that this sequence had been well and truly broken by the arrival of three new models called the "P" Series. Models P4, P5 and P6 (you have to be something of a historian to know about P1 to 3—P2 was reviewed in August 1967—IH) were an immediate attraction in their super slim, exquisitely veneered cabinets. Listening in the noisy Earl's Court exhibition hall was a non-event but even there one h41 the feeling that this new series was going to run and run. Not unexpectedly, demand for production models caused a pleasurable rubbing of hands in the B&W camp and it took some persuading before I managed to get hold of an early pair of P4s (in an attractive cherry veneer) to enable me to offer this report. I chose P4, the smallest of the trio, because it incorporates two developments new to B&W: a folded line bass reflex cabinet, so successfully used by TDL in their model RTL2 (reviewed in December 1993), and a tiny Neodymium magnet version of their celebrated metal dome tweeter. A further reason was that the two bigger models bore rather a close resemblance, at any rate in layout and unit complement, to the recent 803 and 804—both subjects of the previously mentioned Mark 2 regime. However, in the P Series versions the expensively honeycombed Matrix cabinet has been dropped in favour of a more regular construction with the alternative of internal partitioning to add strength and break up standing wave patterns.

The P4 is a two unit loudspeaker using a Kevlar coned bass/ midrange driver crossing over at around 3-5 kHz to a new variant of B&W's long established light metal dome tweeter. This version, no wider than a matchbox, clearly demonstrates the size reduction that is possible through the incorporation of Neodymium in the magnet material without sacrificing the high flux density around the voice-coil which is required to maintain sensitivity and a fast response to transient sounds. In this application the only advantage of the reduced diameter is to enable closer proximity to the main unit, which can be an aid to cohesive integration. To this end the new unit is fitted with a bevelled escutcheon recessed into the front panel.

The 168mm outside diameter bass/midrange unit is of familiar B&W construction on a very open die-cast alloy chassis. This provides a very rigid mounting for the large ceramic magnet assembly, together with a firm seating in the recess provided in the baffle. The woven Kevlar cone is 120mm in diameter and is quite mildly tapered; it is fitted with a 30mm diameter voice-coil of 3.8 ohms DC resistance, centred in the magnet gap with the usual concentric bellows. The outer suspension is a convex rubber moulding providing a reasonably long throw and a sample unit showed a free-air resonance at 40Hz.

The crossover filter components are fixed to a printed circuit board behind the input terminal panel which is recessed into the lower rear wall of the cabinet. Outwardly this displays four large gold-plated terminals with 4mm centres, each accessing one half of the filter for bi-wiring or bi-amplification; these are normally paralleled with the links provided. The bass/midrange section consists of only a single iron-dust cored inductor of I .75mFl; the treble section is a capacitor/inductor 'T' with a 1.5 ohms resistor to equalise the sensitivities of the two units.

All three P Series cabinets are only 200mm wide to minimise diffraction, but they differ in depth and height, the latter being just 810mm in the case of the P4. An optional plinth can be fitted for situations where there is the risk of knocking them over. Optional too are the floor spikes provided. There is evidence that rather more thought than usual has gone into the cabinet design and the choice of materials to control its behaviour. The front baffle, the two vertical sides of which are bevelled, is Specification of 25mm thick particle board and the rear panel 18mm particle board; the remainder, including the internal partitioning, is of 18mm MDF. The latter folds up the internal volume below the bass/midrange unit, effectively providing a long tunnel to the oblong reflex port adjacent to it; thus the source of all parts of the frequency spectrum originates in the upper part of the front face, well away from the floor. It is interesting to observe a large-scale manufacturer like B&W experimenting with alternative methods of bass loading after many years of using the standard reflex Thiele/Small alignment rules. There was a B&W precedent— many years ago I recall the model DM2 used a similar arrangement of internal ducting.

An impedance check on the P4 showed the usual reflex pair of band-pass resonances at 22 and 67Hz, very asymmetric, the former much the smaller. Incidentally, this test brought into question the quoted 'nominal' impedance of 8 ohms; like most these days each new model drops a little lower to enhance the sensitivity figures, so it must be mentioned that P4 falls to 4 ohms at some frequencies. The front, back, top and sides of the cabinet are all expertly veneered in real wood and given a smooth satin gloss finish. An intriguingly shaped cloth covered grille optionally covers the sound sources to provide the finishing touch to this attractive and excellently executed design which will find ready acceptance in surroundings of all periods.

The 168mm outside diameter bass/midrange unit is of familiar B&W construction on a very open die-cast alloy chassis. This provides a very rigid mounting for the large ceramic magnet assembly, together with a firm seating in the recess provided in the baffle. The woven Kevlar cone is 120mm in diameter and is quite mildly tapered; it is fitted with a 30mm diameter voice-coil of 3.8 ohms DC resistance, centred in the magnet gap with the usual concentric bellows. The outer suspension is a convex rubber moulding providing a reasonably long throw and a sample unit showed a free-air resonance at 40Hz.

The crossover filter components are fixed to a printed circuit board behind the input terminal panel which is recessed into the lower rear wall of the cabinet. Outwardly this displays four large gold-plated terminals with 4mm centres, each accessing one half of the filter for bi-wiring or bi-amplification; these are normally paralleled with the links provided. The bass/midrange section consists of only a single iron-dust cored inductor of I .75mFl; the treble section is a capacitor/inductor 'T' with a 1.5 ohms resistor to equalise the sensitivities of the two units.

All three P Series cabinets are only 200mm wide to minimise diffraction, but they differ in depth and height, the latter being just 810mm in the case of the P4. An optional plinth can be fitted for situations where there is the risk of knocking them over. Optional too are the floor spikes provided. There is evidence that rather more thought than usual has gone into the cabinet design and the choice of materials to control its behaviour. The front baffle, the two vertical sides of which are bevelled, is Specification of 25mm thick particle board and the rear panel 18mm particle board; the remainder, including the internal partitioning, is of 18mm MDF. The latter folds up the internal volume below the bass/midrange unit, effectively providing a long tunnel to the oblong reflex port adjacent to it; thus the source of all parts of the frequency spectrum originates in the upper part of the front face, well away from the floor. It is interesting to observe a large-scale manufacturer like B&W experimenting with alternative methods of bass loading after many years of using the standard reflex Thiele/Small alignment rules. There was a B&W precedent— many years ago I recall the model DM2 used a similar arrangement of internal ducting.

An impedance check on the P4 showed the usual reflex pair of band-pass resonances at 22 and 67Hz, very asymmetric, the former much the smaller. Incidentally, this test brought into question the quoted 'nominal' impedance of 8 ohms; like most these days each new model drops a little lower to enhance the sensitivity figures, so it must be mentioned that P4 falls to 4 ohms at some frequencies. The front, back, top and sides of the cabinet are all expertly veneered in real wood and given a smooth satin gloss finish. An intriguingly shaped cloth covered grille optionally covers the sound sources to provide the finishing touch to this attractive and excellently executed design which will find ready acceptance in surroundings of all periods.

Although I have been into some detail in this report, as befits a new design from such an important company, let there be no mistake: this is a fine loudspeaker, able to do justice to a wide range of music at more than adequate volume in larger than average rooms given a clean driving source in the 100 to 150 watts area. It has a wide and reasonably level frequency range and good imaging characteristics. It is also beautifully made, inside and out, and is attractively styled to boot, with a choice of fine real wood veneers. At £600 this one is going places.

Specification

Type: Two-way, folded line bass reflex. Drive units: 165mm Kevlar cone bass/midrange; 26mm metal dome tweeter. Crossover frequencyL 3.5kHz. Frequency response: 50Hz-20kHz ±2dB. Sensitivity: 88dB for 2.83V at 1m. Nominal impedance: 8ohms (minimum 4.5 ohms). Recommended amplifier rating: 50-120 watts into 4 ohms. Dimensions (HxWxD) 810x200x240mm. Weight: 13.5kg. UK retail price: £599.95.

Geoffrey Horn