Celestion 5 Bookshelf speakers
Although we are taught the relationship between the side lengths and the volume of a "rectangular solid" at school, it can remain surprising how small an increase in the former is required to produce a very large change in the latter. This Celestion 5 has an internal volume of exactly one and a half times that of the Celestion 3, yet it looks only marginally larger.
It may be recalled that the '3' was the result of a brief to Martin Roberts, a talented young design engineer at Celestion, to produce a brand new compact loudspeaker which would make a substantial impact in the £ 100 area of the marketplace; he was severely constrained by his budget yet managed to come up with a remarkably innovative design which pleased reviewers, dealers and public alike, and whose impact was really more storm-like than substantial. The same sort of considerations were imposed for the Celestion 5-albeit scaled up - and the same kind of solutions have been adopted. It has the same sort of driver complement and uses moulded polycarbonate for the fascia plates of both tweeter and bass/midrange unit. Again, this is taken further in that the chassis, or 'basket', of the latter is included in the moulding to achieve a composite structure whose stiffness-to-mass ratio is high compared with conventional pressed steel chassis. All other things remaining equal, benefits in articulation, particularly in the bass area, can be expected as a result.
The Celestion 5 uses the same 25mm two-piece titanium dome tweeter as the '3' but partners it with a larger 150mm (as opposed to 130mm) felted-fibre cone bass/midrange unit. As before, this has a convex (rubber) roll surround and central dust cap. The tweeter is protected from casual damage by three curved bars which are integral to the fascia. Both drivers employ substantial ceramic magnets and their inherent response characteristics are linear enough for a simple, five-element crossover 10 be sufficient. Two chokes (ferrite cored in the feed to the LF driver, air-cored for the tweeter), two capacitors and a matching resistor are used, giving second-order slopes centred on 4kHz (asking more of the tweeter than in the '3' where the turnover point is set at 5kHz). The crossover is hard-wired and the components are fixed to the back of the plastic s input terminal block with epoxy adhesive. Just two of these terminals were filled to the review pair (the promotional leaflet talks of four to permit bi-wiring) of the type which accept 4mm plugs or bare wire ends.
The enclosure is a 12-litre sealedbox type. Five of the panels are made of 12mm thick high density particle board but the baffle itself is 15mm thick, combining with the fascia mounting plates to produce a substantial mechanical 'reference', as it were, for the whole cabinet. The rear panel is fractionally inset, further strengthening the system. Internally there is a loose fold of BAF (bonded acetate fibre) wadding 10 help absorb the internal standing waves. The forward edges of the side panels are chamfered as before, though the shallow angle was no doubt chosen as much for its aesthetic effect as it was to improve diffraction at the baffle edges. The front and rear are mall black, the top, bottom and sides wrap-covered (and very well indeed) with a wood-effect vinyl, either black ash or oak. The baffle is covered by a removable, fabric-covered plastics frame which maintains the panel chamfer. It also repeats the Celestion 5 logo which appears on the lower part of the bass/midrange fascia plate.
How it performed
Like the '3', this loudspeaker has been balanced to give optimum results when placed on a shelf or on stands close to the rear wall. Celestion recommend stands 24 inches high, with 6-12 inches of clear space behind the cabinets. The sensitivity of the '5' is enhanced over it s smaller brother by some 2dB to 88dB/Watt/metre and the power handling from 60 Watts to 90 Watts programme - amplifiers of between 10 and 90 Watts per channel into 8 Ohms being recommended as suitable. The impedance curve is an easy one, with the inevitable peaks occurring at around 76Hz and 2kHz; what is important is that the troughs never dip below 6 Ohms in the band from 60Hz-5kHz and even at the extreme treble the load holds up well.
As usual, pink noise was used to assess the off-axis dispersion. The roll-off with lateral movement was very smooth; above axis it was smooth again, confirming the excellent integration of the two drive units in the crossover region. Below axis there is the expected glitch that obtains with vertically in-line drivers; this simply confirms the recommended height, with the ears at, or slightly above, the tweeter axis.
The Celestion 5 has a clear family resemblance to the '3' but is ahead of it in one or two significant areas, as one would expect for an increase in the asking price of some 37 per cent. It has an altogether more natural response to the human voice, with fine articulation and a greater sense of headroom even in my fair-sized room-this is often an obvious limitation with small loudspeakers. Even so cruel a test as the solo female voice was passed in some style; I have been listening quite a lot lately to Elly Ameling's 1982 recording of Schubert's An Die Musik (Philips 410 037-2PH, 10/83), a particularly happy sound to my mind, with the piano (Dalton Baldwin) and voice in quite excellent accord. Small details of the acoustic's 'signature', little nuances of the voice, register well and there is no obvious coloration in the all-important vocal midrange.
Turning to larger forces I was impressed too by its ability to decipher even the relatively complex orchestral textures of a work such as Lutoslawski's early Symphonic variations in the 1978 EMI/Polish Radio, recording with the Polish Radio National Symphony Orchestra under the composer's baton (reissued on EMI CDM7 69840-2, 9/89), the rather bright, almost astringent, sound conveyed well and without extra emphasis. The stereo projection is extremely impressive and provided they are sensibly positioned the '5s can generate an almost holographic sense of space around them. The bass is inevitably lacking in weight (though it is usefully bolstered by the recommended placement near the room boundary) but what is there is clean, with no artificial hangover; this is due partly to the closed-box loading but more significantly to the responsiveness of the drive unit, which is clearly very well tailored to this application.
One can always find limitations in a design and it is easy to say how this or that aspect could be bettered. But that really isn't the point-any half-decent manufacturer will juggle with the compromises that have to be accepted in manufacturing a product at a given price, and will know full well how it could be improved given a larger budget. Criticism is only really relevant in context, and in context, from a manufacturer who is not half but wholly decent, the Celestion 5 is another most impressive loudspeaker.
