Now, a 50 Watt valve amp might not seem like such a great choice for driving a sub-woofer, but actually, there’s a few things running its way in this instance. At 89dB sensitivity and a flat 8 Ohm impedance, the WATCH Dog is a far from frightening load. Nor is their any passive crossover to get between the amp and the cone it has to control, while the ported cabinet might trade off linearity but gains power and dynamic range where its both useful and controllable by a smallish amp. Or, in other words, if you are going to offer a passive sub, don’t give it electrical characteristics that demand a kW to get it moving. I won’t insult the Dog by calling it a pussycat, but it is the next best thing. With the VAS amps hooked up and the levels trimmed to accommodate their different balance to the ARC, listening could begin in earnest. Where better to start than the completely OTT demands of the Gladiator OST? I know, bass and dynamic range are only two of the things that subs do, but if they don’t do those they don’t do the other, arguably more interesting stuff either. Listening with the Duettes alone, they produce a remarkably impressive sense of power and scale given their compact dimensions. But adding the WATCH Dog exacts a dramatic improvement. Take track 13, ‘Barbarian Horde’, as an example. With the sub in play, the lilting opening melody hangs in a huge acoustic space. The background is blacker, the air more transparent and free of grain. The effect is to heighten the contrast, enhance the delicate fragility of the solo instrument. There’s even a gentle rumble of fading bass, just to further bring home the sense of isolation, which passes all but unnoticed on the Duettes solo. With no low-frequency notes to speak of the tension and atmosphere evoked leave you in no doubt that this is an entirely different musical experience. Instrumental positioning is much more apparent, the sweeping nature of the orchestration, as is the slow, measured tempo of the building power beneath the music, the sense of menace and foreboding. With the Duettes alone, the first crescendo grows as a single entity from the centre of the stage: with the Dog doing its thing, it rises and swells from the floor, not just full of extra weight and surging power, but full of complex textures too. But perhaps most important of all, with just the standmounts it reaches a strain and intensity that whilst musically impressive leaves nothing for the excesses to come. The WATCH Dog keeps everything well within the system’s compass, banishing strain and replacing it with natural drama whilst leaving one in no doubt that musically (and in hi-fi terms) there’s plenty more on the way. It’s all about building anticipation and it’s a quality critical to the music, both in its own right and as an adjunct to the action on the screen. Those echoes of ‘Mars’ are no coincidence, their influence so much clearer with the sub-woofer in circuit. And it’s not just to do with the drums either. Listen to track four with its theme so clearly stolen from Lt Kije. With the WATCH Dog underpinning the sound, instrumental textures and tonality across the entire range become clearer and more natural, colours and flavours more obvious, the musical contrasts and drama more vivid.
More there is and more you get. It’s not just that the music goes bigger and louder with the sub-woofer – it’s the nature of the increase, the way it happens that makes it seem bigger even than it is, whilst ensuring that you hear the benefits even on solo instrument and voice, at ppp as well as fff. So, whilst the towering crescendos of Gladiator’s battle scenes take on a properly imposing, almost monumental scale and complexity, the system holding the many instruments separate, identifiable by position, note and texture, that individual finesse and the spatial and musical coherence on which it depends gives the same presence and drama to the isolated three-note guitar phrase that opens Dolly Varden’s latest album, The Panic Bell (cd035 at www. undertownmusic.com). Those three notes, distinct, vibrant and immediately alive, encapsulate in a single musical moment the benefits and musical imperatives of coherent bandwidth. The sub doesn’t just bring texture, tone and shape to each note, it spaces them, picks up the damping that kills the tail of the third, stretches out the space silence between it and the leading edge of the reprise. It brings intent and attack to the chords that build on the end of that first repetition, keeps each subsequent repetition present and intact as the track builds around it. Sub’s might be big, visually (and all too often musically) brutal, but the bandwidth they delivers operates most importantly and obviously ay the opposite end of the scale. The top-to-bottom linearity they promise underpins the harmonic development of notes, their point and place in time and space. It clarifies the scale, the structure, the relationships within music, within bands, within individual notes and chords. It’s all about expression and emotion, the grit and finesse, the humanity in the performance, communicating the music as a whole and the message it contains. Which is why a good subwoofer is more obvious on small-scale work, where the clarity, texture and subtlety it delivers has the space and the system the power to reveal its true nature. Move down in frequency and up in level and the demands placed on the amplification, drivers and cabinets increase exponentially. Of course, with modern switching power supplies, a small, affordable and previously unfeasibly powerful amp is possible – which is why so many inexpensive subs claim amplification measured in hundreds of Watts, if not a thousand or so… The question is, at what point do you throw out the baby with the bath water?