Alongside PMCs popular FB1 and OB1 floorstanders, the company also produces a range of rather more substantial designs that are derived from the models it develops for the 'pro' audio industry.

The latter are mostly actively driven types with amplification made by Canuck power meisters Bryston, customised to PMC's specification.

On a recent visit to the Metropolis studios in Chiswick, we got to hear a stacked pair of PMC BB5s, a combination of a bass cabinet with a 380mm driver under a three-way, full-range cab with the same bass unit again, plus a midrange dome and big 34mm tweeter. The whole ensemble stands over two metres high and is backed up by 2,100 watts per channel.

Fortunately, the mastering engineer using them was a sensible chap and wasn't out to impress us with SPLs. Instead, he played a variety of recent projects and explained that the speakers frequently caused problems with clients who had not heard their work properly before because of lesser quality monitoring in the studio. The speaker opens the window too wide for many recordings. This is the gene pool from which the new EB1 has spawned.

While it is a cheeky little speaker by the BB5's standards, it is still huskier than your average floorstander. Having said that, it's attractively slim for something carrying a 250mm bass driver. As a design, it derives from the IB1, which has the same drive units, but comes in a cabinet that is 3.4cm wider but only 74cm high.

As it's a standmount it ends up being a similar height to the EB1 in practice, but is somewhat inelegant by comparison. There was a time when the accommodating other half would put up with such a thing in the living room but since Grand Designs and the like arrived on our screens, loudspeakers have had to shrink or get a lot sexier to claim their piece of domestic real estate.

The EB1 is still not a compact speaker by any stretch, but it is very nicely put together and looks great in a walnut or indeed the cherry veneer as tested here.

Transmission line loading

As with all of PMC's designs, the cabinet uses transmission line loading rather than the conventional reflex porting. In the case of the EB1 we have what the company calls an ATL or advanced transmission line.

Advanced being a description for the way that PMC uses a combination of foams that it developed with bed specialist Relyon to damp the line and thus more accurately tune the frequencies that exit the vent. A pure transmission line absorbs all the rearward radiation from a drive unit, B&W's Nautilus tube being a good example - but that requires an unfeasibly long damped tube behind the bass driver.

PMC operates its transmission line rather like a crossover, by using damping to filter out bass above 100Hz and making a quarter-wave length line whose output takes over from the bass unit below 40Hz. This approach simultaneously increases extension and substantialy reduces harmonic distortion in the bass.

The EB1 has a three-metre transmission line, which in the company of a 250mm chassis bass driver, makes for bass extension that's claimed to go all the way down to 19Hz (-6dB). The weird looking flat bass driver is made from a sandwich of carbon fibre outer skins with a Nomex honeycomb centre.

The end result being similar to Focal's glass/foam 'W' cones, both are light and stiff structures, designed to approach perfect pistonic action. This system has both pros and cons: on the plus side, the inherent strength means that power handling is unusually high, but against this, the extra weight that the longer than average motor assembly introduces inevitably reduces sensitivity.

This is combated by the use of an enormous magnet assembly that drives a 75mm edge wound voice coil - which is another pro style, power handling aid.

The 75mm midrange dome is a soft fabric unit that vents to a true transmission line behind it. This is shaped somewhat like a tapering flower pot with a rounded end, and is filled with wadding that gradually damps the rearward energy from the dome.

Bitumastic is used to damp this chamber and is also extensively used to nullify any activity in the 18mm MDF carcass. Although this doesn't seem particularly thick for a speaker of these proportions, when you consider that the transmission line provides very substantial bracing throughout the box, it seems a little more sensible.

Meaty, Beaty, Big and Bouncy isn't just a Who record from the 1960s anymore, it's now also a great way to describe the sound of this remarkably entertaining and capable loudspeaker, as that's the way it sounds if you play high energy material at high levels.