Velodyne DD-12
Subwoofer

Velodyne Digital Drive DD-12 subwoofer

Velodyne DD-12

Subwoofers are a must for the hip home-theatre set, but what about the hi-fi stereo crowd? With their unfashionable trousers and Neil Sedaka collections, can the two-channel fraternity have use for a T-Rex footfall generator? Yes indeed, the modern audiophile will run the risk of loosening his dentures in order to experience the frequency extension, sense of space and solidity, and added realism that a carefully tuned upmarket sub can provide.

Committed hi-fi enthusiasts try their subwoofers in thirty to three hundred different locations in their listening rooms. Once it works tolerably well, every occasion on which it is used becomes an excuse to adjust all its settings because every track played reveals a new deviation from perfection in bass response.

The problem with bass is its interaction with the boundaries of the space it sounds in. The result is bloat in some low notes and fade in others, as nodes and anti-nodes are generated in the room at different frequencies. Some rooms are relatively benign, thanks to their proportions, but many, like my own, are almost impossible to tame.

Box of tricks

Velodyne, an American company as famous for their subwoofers as Welsh competitor REL, has introduced a range of subs intended to reduce the suffering of the audiophile trapped in the hell of constant fine-tuning. The Digital Drive series, from the baby DD-10 with a 10" driver, to an 18" monster I hope never to have to carry up my stairs, all feature onboard room-equalisation electronics that greatly reduce the misery of proper subwoofer installation.

After unpacking the surprisingly heavy DD-12, I set it down where my similarly sized Audio-Pro usually resides. Bass frequency response here is far from flat, but it remains the preferred spot in my uncooperative listening space. This sub can act as a high-pass filter for the main stereo speakers, leaving them with nothing over 80Hz to worry about, but I chose to let my speakers run full-range. Without any adjustment save for volume, the Velodyne immediately impressed with its speed and extension. As this produced tolerable results, I decided to leave it in this 'raw' state while we got acquainted.

My hump

After a week of regular duties in my system, I took the first step in tuning the Velodyne. This involved placing the microphone included in the optional Digital Drive equalisation kit on my listening seat and connecting it to the sub. Pressing 3-2-1 into the sub's remote causes it to undertake a series of frequency sweeps, listen to the results, and alter its balance automatically.

The improvement was not subtle - suddenly the bass filled out where it had been shy, and flattened where it was too exuberant, with the reward that music became far more believable, irrespective of its bass content. The aforementioned virtues of the DD-12 were reinforced, as the speed was emphasised by the lack of overhang in nodal frequencies, and the extension reinforced by compensation for an anti-node in the upper bass range. Set the controls for the heart of the bass

Another few days passed, and again I connected up the microphone, but this time the frequency sweep was piped through my stereo amp, via RCA outputs on the sub. Video output was run from the sub to my TV for a graphical display of equalisation settings and system response. Now I could see the frequency output of my main speakers from 15 to 200Hz. Switching from the equalisation screen, I was shown a list of advanced settings for cross-over frequency, roll-off rate, phase, polarity, and more. I made a few adjustments, then switched back to the equaliser to tweak the sub's response at different frequency ranges. After much trial and error, I was able to get my system sounding very even, although the graphics showed me I still suffered deviations from the ideal that were beyond the sub's power to correct.

Feel the love

Is it all worth it? For me, and maybe for most users, the best bit is the Velodyne's ability to self-tune. As I was unwilling to rearrange my lounge, my manual adjustments made only marginal improvements on the sub's own reactions. However, if the Velodyne were mine, and not just a loaner, I'd use it's abilities to find new locations for both my main speakers, my listening position, and the sub, with undoubtedly better results than I got on my short acquaintance with it.

If your system lives in a room with exemplary sonic characteristics, you can opt out of the Digital Drive tuning kit. However, if your main speakers cost around the same as the DD-12, and you have a 'difficult' room, I'd definitely recommend the full package.