Supertweeters really work, bringing not only better treble extension but superior midband focus too – especially when you’ve got a good source with an extended top end in the first place, of course. So when the Maximum was launched in the early part of the noughties, I sat up and took notice. Here was a beautifully packaged and compact device using a high quality ribbon, and was even fairly sensibly priced at just £800 per pair. What was not to like?
The Maximum comes in a very petite (50x30x100mm) casing in a choice of either titanium or stainless steel mirror finish which looks exquisite; in some way redolent of a nineteen fifties broadcast microphone. Pressure relief vents in the sides of the case are provided to allow the air pressure on the ribbon to equalise in the event of sudden pressure changes. Inside is a super-powerful neodymium magnet and an ultra thin eight micron pure aluminium ribbon, plus a simple crossover to set the sensitivity. All copper conductors, including the matching transformer windings and the aluminium ribbon, use Townshend Audio’s Deep Cryogenically Treated (DCT) process, as found in its Isolda loudspeaker cables, and are heat annealed (-190C to +150C).
Output may be set to suit loudspeakers with sensitivities from 80-110dB, adjusted in steps by a rear-mounted eight-position switch. In this respect, it’s better than Tannoy’s five-way jumper system on the ST-100 supertweeter, which offers less control over attenuation (87-95dB) but does sport three different crossover frequencies – so it’s swings and roundabouts. Also on the back are the usual 4mm banana sockets. The kit comes complete with a set of very high quality 1.5m DCT cables, for wiring to the main speaker terminals via spade or piggy back connectors. Townshend claims they’ll work connected directly across the output of amplifiers up to 350W, and there’s an automatically resetting fuse to prevent ribbon damage in the event of overload.
The idea is simple. Although human hearing rarely extends beyond 20kHz, we can ‘perceive’ (if not actually hear) higher – which is partly why the brickwall filtering of CD at 20kHz sounds so unnatural. To wit, the Maximums run from 20-70kHz (at –3dB points), or 12-90kHz (at –6dB), thus ‘filling in’ the ultra high frequency spectrum. There’s another boon too – just as subwoofers seem to take the strain off loudspeaker bass units, making them altogether more fluid and unforced, so supertweeters seem to sweeten the treble. There’s a small but obvious improvement in fluidity and ease in the high frequency region, which (interestingly) stretches down to the upper midband.
I first heard the Maximum with Quad ESL-989 electrostatics, and the difference was staggering – they proved just what the Quads have always wanted. There was a real improvement in treble performance which I’ve always thought to be superb in some respects but flawed in others (they’re too veiled). The Maximums added a subtle but oh-so-welcome atmosphere and spatiality in both treble and upper midband regions. More impressive was the extra speed they brought – attack transients (the leading edges of notes from strummed steel string guitars, for example) had better definition. Despite this, there absolutely no change in tonality; things didn’t sound brighter, just faster. Then and now, a great niche product.