AudioPro ACE-Bass 2

A good subwoofer adds impact, substance and (quite literally) feeling to your aural experiences. A great subwoofer will do all this and then some--it'll even extend the frequency range of your system by alleviating some of the bass load from your main speakers. With such an important job in a hi-fi or home theatre system the task of finding the right subwoofer shouldn't be rushed. Performance is obviously key and should be uppermost in your mind when auditioning prospective purchases. In reality we're often dictated to by other, less exciting factors such as the size and layout of the lounge. If you find you're lacking in space and need a compact subwoofer that doesn't compromise on performance then we think we've found just the toy for you.

The ACE-Bass 2 from Swedish manufacturer Audio Pro is as compact as they come, yet provides a phenomenal amount of deep, clean, distortion-free sub-bass. One of the problems faced by subwoofer manufacturers is that of transient response--how quickly the woofer cone reacts to the audio signal and, just as importantly, how quickly it stops moving afterwards. Generally speaking, the larger the woofer the slower the transient response and the higher the distortion. Paradoxically, most subwoofer manufacturers tend to opt for large woofers (in excess of 10") in the quest to create deep, powerful bass. There are, however, ways of moving the same amount of air without the slow transient response and distortion associated with large woofers. Multiple small woofers are one such option--in the case of the ACE-Bass 2 sub, a quartet of 5.5"-long throw units with neodymium magnets are installed.

The absence of a traditional bass reflex port (which needs to be of a minimum length to be of any use) means AudioPro can substantially reduce the cabinet size. A 10" passive radiator on the front of the cabinet allows air to move but the sealed-box nature of the system means an incredibly powerful 500W D-Class amplifier has had to be installed.

On the back panel we find heavy-duty, binding post-style speaker level inputs and outputs plus an LFE-in (low frequency effects) socket and stereo line in and out sockets, and next to these are the variable low pass filter, phase and volume controls.

So has all this effort paid off? You bet it has. Musically I've yet to hear a modern subwoofer that can match the Audio Pro in terms of speed and detail. Play any up-tempo song with a strong bass line and you'll find the precision and depth with which that bass is reproduced quite astounding. Plucks of a bass guitar are clearly distinguishable from one another, even among the hubbub of a band's worth of instruments. Detail is outstanding too. Take any track from the Lisa Ekdahl/Peter Nordahl Trio album Back to Earth and listen for Patrik Boman's double bass; when he hits the real low notes you can almost reach out and feel the resonance of the instrument.

Home theatre nuts will also love the speed of the ACE-Bass 2. Machine gunfire in The Matrix or other similarly fast-paced movies transcends the constant blur of ordinary sub bass and every shot slams home as an individual entity. Best of all it integrated superbly with the mains (also Audio Pro in this case) and like all good subs it never once drew attention to itself.

Being such a small unit it's not going to pop your windows from their frames but it will give them a good old rattle if you like your bass big. Highly recommended.