Despite the assertions of many loudspeaker designers that active loudspeakers are the future, and regardless of their considerable success in the pro-audio world, they just haven't caught on.

The most obvious and probably most important reason is simply that most audiophiles don't like having their choice of amplifier dictated to them. Even if they're happy to take on trust the quality of amps fitted inside a speaker, they probably already own amps that they like and are loath to part with.

That said, ATC and others do sell actives to domestic users. The press release accompanying this new model suggests that it will suit stereo and multi-channel systems in small to medium rooms, or even ''the ultimate MP3 PA system!'' Well, yes, we suppose so...

At the very least you'll need some custom-made adaptor cables, as the SCM16A features only a balanced XLR input - a clear sign of its professional heritage.

As is usual from ATC, the model number refers to internal volume in litres, so this is not a particularly large speaker. It is heavy, though, due not only to the typically chunky ATC bass driver, but also to the substantial toroidal mains transformer that feeds the internal amp.

The enclosure is relatively light, being cast in aluminium along with the fairly gigantic heatsink at the back. Presumably, this cost a bit to tool-up, but it must make manufacture relatively swift and straightforward, and also means that overheating is never likely to be a problem as the enclosure also dumps waste heat from the high-biased Class AB amp.

The latter delivers 200 watts into the bass driver and 50 watts into the tweeter, with an electronic crossover separating the frequency bands at small-signal level.

The advantages of that are precision and the ease with which rapid crossover slopes may be implemented. ATC uses fourth-order slopes, limiting the out-of-band drive to each unit and hence reducing distortion: even faster slopes can have audible ringing effects for listeners placed off the ideal axis of each speaker.

Build-wise, the amplifier is a straightforward affair, very robustly built on a circuit board mounted directly inside the enclosure.

ATC makes all its own bass/mid drivers and this one is a six-inch unit shared with the SCM11. The unit's heavily doped cone uses constrained layer damping to reduce resonance and hence distortion due to cone break-up at higher frequencies, and its central dust cap doubles as a soft dome. The tweeter is a soft dome type, 25mm in diameter.

In keeping with current curvy trends, the enclosure of the SCM16A is rounded off at the edges of the front baffle, and both curved and tapered towards the rear.

While this won't eliminate internal resonance entirely, it is a good way of reducing its effects considerably while also reducing the severity of structural resonance within the enclosure.

Aluminium is not the 'deadest' material around, but a quick check, tapping the side at various places, does confirm that, in this case, it offers very good performance.

There is, of course, internal damping in the form of fibre wadding and the front baffle is made of thick MDF and pretty well damped by the combination of its interface to the bass/mid driver and the rest of the enclosure. There is no reflex port, ATC preferring sealed-box construction for all of its smaller models.