Acoustic Energy AE2 Bookshelf speakers

Question: should an engineer long experienced in rigging, servicing and using loudspeakers for high-power live shows and recording do a poacher-turned-gamekeeper act and start designing and marketing loudspeakers of his own? My normal answer to this question would be a firm "No", on the grounds that designing a loudspeaker that can be consistently fabric a ted to acceptable standards is a job for the trained specialist. However on the evidence of this remarkably good-sounding loudspeaker I am more than ready to make an exception of its designer Phil Jones.

"At the bottom end of the market, of course, any Tom, Dick or Harry can go into the loudspeaker manufacturing business. Drive units can be bought off the shelf and nailed into any old box. The driver manufacturers are usually more than ready to leave their own names off the units and offer enough advice on the boxes and crossovers to enable our entrepreneur to launch three graded models at £99, £149 and £199 tomorrow.

But what Acoustic Energy have done is to produce a range of three quite expensive systems built with lots of new ideas and ambitious specifications. They began with the AE1 (£695,75) mini monitor designed to surpass the performance standards accepted by most recording and broadcasting engineers for the job of near-field monitoring. That is the use of small speakers perched on the mixing console as an alternative to the monster wall-mounted monitors when the producer wants to hear how his balance will sound at domestic levels. In the event, studio engineers have been slow to buy the AE1, preferring to soldier on with their existing cheaper near-field boxes, but the AE1 has been making quite a stir in the domestic market where high fidelity from tiny LS3/5 A sized speakers is much in demand.

Now the range has been built up to three models by the simple expedient of using two of the bass units for this AE2 model (£999) and four of them for the AE4 (£1,799'75). The AE2 is still fairly compact in size but weighs a substantial 17kg to confirm that the novel design features are not all on the surface.

To begin with the drive units, it has been a deliberate decision to use metal diaphragms and edge-wound ribbon coils for both the 25mm tweeter and the 130mm bass/midrange sourced (with specially demanded characteristics) from Elac. The tweeter is not greatly different from the metal-domed unit now appearing on speakers from Monitor Audio and others. It has a lighter copper-plated aluminum coil thermally bonded to a magnesium alloy dome, making the dome act as a heat dispenser in support of the ferrofluid cooling and damped rear chamber contributions.

The bass driver follows this same philosophy with the coil assembly glued on to the heat-conducting cone and dustcap in an attempt to get away from the 'thermal compression' which so often limits the dynamic fidelity of loudspeakers on peak signals. The coil former is lengthened to mate with the cone but the coil is narrow enough in relation to the magnetic field to allow 20mm peak-to-peak linear excursions. The cone is made of aluminium (shades of the old GEC metal cones of 25 years ago) but has a Phil Jones patented sandwich construction with hard anodization front and back. It is a flat cone without flaring, graduated in thickness from neck to periphery and exceptionally piston-like in its rigidity. Surface treatment reduces ringing, assisted by the foam surround. The dustcap is a spun aluminum sharp-pointed cone.

The crossover network operates at 3kHz and is fairly steep-sided. It uses first class components silver soldered on to a board which also carries good quality 4mm binding posts and is firmly bolted behind a recess in the rear panel. The tweeter and bass circuits are wired to separate pairs of terminals to permit the use of bi-amplified drive or bi-wiring.

The heavy enclosure is also unconventional. It is based on 22mm thick MDF (medium density fiberboard) which is already more substantial than usual. To the vertical sides of this an internal coating of plaster-type bonding has been added. This is poured in and allowed to set hard while the carcass is held at an angle, first for one side and then for the other, so that non-parallel walls result and effectively spread the internal standing wave frequencies to avoid box resonances. Bass reflex loading is used, there being three small circular vents in the front baffle with rounded apertures to minimize edge effects. The external finish is textured black which should match both professional and domestic equipment.

How they performed

Evaluating these loudspeakers has not been a process of finding faults so much as discovering one felicitous feature after another. First I was captivated by the handling of the top half of the spectrum. The smooth and consistent response to treble sounds of all kinds gave a clarity to strings, voices and brass which was at the same time analytical and true to life. Dynamics have something to do with this, of course, and the absence of treble crushing on cymbals and the like was impressive. Such peaks occur only occasionally in most classical music but are very much in evidence on pop music. Pop enthusiasts and engineers will love this aspect of the AE2 performance but will also appreciate the effortless power handling, tight bass and almost complete avoidance of cabinet boom.

There is an ever so slight lift around 250Hz which sometimes reminds us that we are listening to enclosures of modest proportions, but the extreme bass roll-off is a model of smoothness and sounds ideally balanced. Indeed the extreme treble does not extend upwards for ever, so that LP surface noise and sibilants for instance are not exaggerated. Sensitivity is above average but a fairly powerful amplifier is recommended since this speaker really comes into its own at something above the most modest domestic listening levels.

Best results were obtained using tall stands (about 60cm or 24 inches) though these had better be strong and well designed to present a really firm and safe platform. The symmetrical arrangement of the two bass drivers with the tweeter offset at the centre would allow a horizontal placement as well as the usual vertical one.

Experimentation with this and the angle to the listening position is definitely recommended (by me, though the makers recommend a straight to the front orientation). With speakers providing this degree of image and balance precision, some degree of fine tuning in the room is merited. Interestingly the designers have taken the trouble to ensure that both the front baffles and grille cloths are Left/Right handed to make the tweeter location a mirror image in the vertical position. I prefer to place the tweeters towards the inner edge, which usually results in a slight inwards shift in the treble listening 'window'. But this is something else to try in your room while listening to stereo-sensitive material.

In a very short space of time, Acoustic Energy have added to our choice of high performance loudspeakers at a price. The tiny AE1 has already attracted keen trade and media attention. This larger AE2 should go straight on to the short-list for anyone looking for high fidelity and high power handling in a surprisingly compact, yet uniquely rigid, cabinet.