SPECIFICATION

Frequency response: 45-20,000Hz

Drive units: 200mm bass, 25mm tweeter

Sensitivity: 87dB SPL at 1 metre for 1 Watt

Power handling: 100W (programme)

Nominal impedance: 8 ohms

Dimensions (H x W x D): 490 x 255 x 295mm

Weight: 10kg

Manufacturer: Wharfedale Ltd., Sandleas Way, Crossgates, Leeds LSI5 8AL UK retail price: £199.90 per pair (black vinyl), £249.90 (mahogany)

HAVE you ever stopped to consider how great is the spread of prices amongst our audio bits and pieces? Certainly with pick-up cartridges since the arrival of certain exotic hand-made moving-coils it has exceeded 1,000:1, although a demographic expert might have some difficulty of scale in illustrating the distribution at the expensive end! In the case of loudspeakers, that extreme ratio probably reduces by something like a factor of ten now that the peak of popular sales has moved up from the £100 at which it stuck for some years in the early 1980s. If I update it to around £200 and suggest that it is not so much a peak but a rolling hill, then that is no more than an educated guess, although it is well supported by the large number of models on the market which occupy this area. I have considerable sympathy for fellow journalists who, being employed by periodicals engaged in the business of monthly comparative reviews, have to listen to and pass judgement on large quantities of them. In the normal course of events, we come within earshot of quite a number of speakers but very few draw us into closer acquaintance; many have the opposite effect. They must all sell, the latter because they are formulated to provide the loudest impression on the ears when fed with a diet of the "Top 20" and the former to those who prefer to get their drama from the score, not their equipment. This suggests a first rule of thumb to be borne in mind by those seeking loudspeakers for the classical repertoire. Quality and quantity are rare companions; it follows then that the more efficient loudspeakers may turn out to be less pleasing to live with. The subject of this report is not one of those.

Wharfedale's Model 507:2 scrapes the £200 price in its simplest form of cabinet, which is constructed of chipboard tastefully covered in a vinyl veneer successfully imitating the now commonly acceptable black ash. For another £50 a superior version is available, fabricated from Medite with a real mahogany veneer; this is said to have a slightly improved performance but has not been auditioned. The origin of this design goes back to a period when loudspeaker engineer Graham Bank was at Wharfedale, and readers may remember my report on the innovative model 708 with its sandwich cabinet and drive unit cone constructed on a moulded 'build ring' and mounted in a frame which locked in to a shaped hole in the cabinet needing no holding screws (December 1985). At the same time the capabilities of metal dome tweeters, which had flowered under Bank's influence when he was at Celestion (he is now back there again), led to the use of an aluminium version in the Wharfedale range. It was a logical process to take these highly developed units and use them in 'ordinary' cabinets and this brought forth the original 5 series in 1984.

The first model 507 appeared only a couple of years ago but a promising new loudspeaker engineer, Wharfedale trained, named Roger Loughton had further ideas to improve the 200mm cone unit and on this showing he certainly has. All the original good features are retained---cast magnesium chassis with the bayonet fixing lugs, the build ring, the composite cone and free suspension—but the important midrange lucidity and definition is superior to the original and the crossover to the (unchanged) tweeter is seamless. More and more loudspeaker designers are moving away from the complex (and expensive) electrical networks which followed on the work done by the BBC in the 1960s. Instead they are persuading the materials employed in the assembly of the moving parts (cone and dome surrounds, damped corrugated suspensions, glues and joints between dissimilar substances) to provide gentle and even roll-offs in the right frequency areas so that very little electrical 'cooking' is needed— in this case only two Inductors and one rather expensive polyester capacitor to feed the tweeter; and it works like a charm.

Computer science has now removed the mystery from achieving the desired bass performance, given a full diet of facts about the variable and invariables (such as cabinet volume), so that they all ought to come out the same. Fortunately there remain a number of facts that do not get into the computer, so we still have a job to do. In this case the designer has elected for a free suspension giving the bass unit an open-air resonance a shade below 30Hz. The cabinet is of moderate size for a 200mm unit and a reflex arrangement has been decided on with a tunnelled port in the rear cabinet wall. Internal absorption with good oldfashioned BAF wadding has produced band-pass resonances at 20Hz and 70Hz. The latter is nicely placed to avoid exaggerating 50 or 100Hz hum from less than state-of-the-art amplifiers, low enough not to ruin male speech, but a useful prop for general low-frequency sound and its early harmonics.

Internally the cabinet is braced with a cut-out plywood frame and the rear panel is deeply recessed to add strength, with the secondary advantage that the two large terminals do not project. The few crossover components are on a small mounting board which is held in.

place by these terminals; the internal wiring is thick multi-strand mated to the units by push-on spring connectors. A cloth covered grille frame is held by spigots into the front cabinet face, leaving an area at the bottom uncovered to disclose the discrete Wharfedale logo.

Wharfedale's genial marketing man, Fred Clayton, suggests from his experience that the optimum placing in one's room should be on 450mm stands of solid construction and about 300mm from the rear wall. After experimentation I would not disagree with him. Having arrived at a suitable placing (rather closer together and further away from the corners than usual) I have enjoyed a great variety of programme material on these moderately priced loudspeakers. Nobody is going to pretend that they seriously rival a number of much more expensive models around the place in frequency range, smoothness, definition or other aspects of fidelity but on the other hand they are singularly lacking in the negative `nasties' which bedevil many low-cost designs. Nothing I have played through them has offended me; more often I have been surprised at their ability. If all this runs the risk of an accusation of damning with faint praise, let me choose one word to describe them— friendly. Friendly to all kinds of music, to the listener and his room and not least to his finances.

GEOFFREY HORN.