The new QR subwoofer is actually the second of two models in the Audiovector line-up, although in the spirit of other Audiovector SR models, the SR Sub is available in Super, Signature, Avantgarde, and Avantgarde Arretè variants. The QR Sub is a more down-to-earth design, with few options as befits products in the company’s entry level QR range: just the choice of black, white, or wood finish in fact. But ‘down-to-earth’ does not mean ‘rudimentary’. This is a very sophisticated subwoofer in and of itself.
The QR Sub uses the trusted combination of forward-firing active and down-firing passive drivers, fed by a powerful amplifier, and includes both high- and low-level inputs for use in audio and audio-video systems. It’s a natural partner for the QR range.
To recap, that QR range is Audiovector’s entry-level range, which features an AMT tweeter and what it refers to as a ‘Pure Piston’ driver for midbass. In a subwoofer, you can forget about the tweeter, but the Pure Piston driver design is used here, in a larger 250mm form. Pure Piston is essentially a sandwich, with aluminium acting as bread, either side of a fibre-filled foamy glue replacing the cheese. So far, there have been discussions about the use of pickle. Lunchtime hunger aside, the point of the Pure Piston driver technology is to use the filling to mitigate the break-up properties of aluminium cones, and the aluminium cones to act as constrained layers for the filling itself. This combines to make a driver that has a ‘best of both’ set of properties, retaining the light and reactive performance of an aluminium cone, without the potential for cone break-up in the audible frequency range. In a subwoofer, especially when faced with a long-throw auxiliary bass radiator firing downwards, cone break-up could significantly interfere with the Presence region, and instead of underpinning a good loudspeaker, the QR Sub would ruin it at a stroke. Fortunately, the Pure Piston drivers seem pathologically incapable of making a poor sounding subwoofer. And, fed by that 350W amplifier, they are well controlled and capable of both surprising depth, and surprising subtlety. The amp can be used auto-sensing, and includes two volume settings, a frequency adjustment, and phase.
The frequency and volume adjustments for stereo loudspeakers only kick in when you use a high-level cable, unfortunately provided as an optional extra. This includes a Neutrik Speakon connector and three wires, designed to be connected to the speaker terminals of your amplifier (the surround sound option takes a phono input feed (the cables for which is also not supplied, and you should use left and right inputs even if you only have a single subwoofer output. Audiovector recommends a Y-splitter). If you are using this in a stereo context, I would recommend using the high-level connections even if there is a subwoofer output on your amplifier, primarily because it sounds better. It can also be made to sound better still with REL’s Bass Line Blue cable.
Set-up is relatively straightforward in either case. With the recommended-for-audio high-level installation, set the frequency to the -6dB point of your loudspeakers to begin with, and then turn the volume up to perform a phase check from your seat, then turn the volume down until the subwoofer is at the limits of audibility. What Audiovector doesn’t suggest is revisiting the installation a couple of weeks later and turning the frequency level up slightly and the level down slightly. Try it – it works!
After-market subwoofers tend to fall into one of two categories; big, booming subs that can do audio in a kind of ‘paying lip service’ manner, and more subtle, faster types that give honest, but not too overblown bass. The QR Sub falls largely into the second camp. The surround sound setting can make this a more full and deep sounding subwoofer, but it’s best used in a more subtle setting to underpin the bass of a good pair of loudspeakers rather than to add extra heft to home cinema explosions. Most of all, though, the QR Sub is extremely fast, which makes it great to add a bit of air and depth to drum kits (real and electronic). When it comes to adding ‘thwack’ to the same, it’s pretty good, too. It’s at this point where it becomes an ideal match for Audiovector’s QR range, in that it’s voiced to retain the same speed of attack these loudspeakers deliver, and yet add some depth. Bigger, more full-sounding floorstanders would perhaps benefit less in the ‘oomph’ stakes.
I tried it with a copy of Augustus Pablo/King Tubby’s ‘King Tubby Meets the Rockers Uptown’ on an old Island CD of the same name, which might just be the best example of dub ever recorded. It’s mid-1970s dub that has a deep, but tuneful bass line instead of the earth moving that came later. Here, the bass lines took on a deep, walking quality that sounds accurate and enjoyable. But most subs can do that.
The mark of a really good subwoofer in an audio context is when its effect is not heard as much in the bass as it is across the midband and treble. It helps open up and open out the midrange, almost as if the system is having to do less work. The Audiovector does this very well, especially with smaller floorstanding loudspeakers where the sense of additional space is palpable. This even opens up the lyrics to make them a shade more intelligible: I played ‘Without Me’ from Eminem’s The Eminem Show album [Interscope], which is so fast paced it’s easy to mis-hear, and time helps make that harder to remember the lyrics. I definitely picked up more words with the QR Sub than without. Unfortunately, it’s all to easy to miss this result and instead drive the subwoofer too high into the upper bass and just add a syrupy bass thickening agent instead, which works entirely against vocal intelligibility. The secret is in the installation, however.
Used carefully and installed with a mind toward improving the sound instead of simply adding bass, the Audiovector QR Sub has a lot to offer thanks to its terrific speed of delivery. It does do deep bass too, more than enough to keep the bassheads in cinema and stereo happy, although there are bigger units that deliver a less subtle but more energetic performance. It sounds paradoxical, but if all you want from your bass is bass, the QR Sub might be gilding the lily. On the other hand, if you want refinement, enhancement to your loudspeakers, and some deft underpinning of the bottom end, the QR Sub subwoofer comes highly recommended.
Type: Active subwoofer with passive radiator
Drive Units: front-firing 250mm ‘Pure Piston’ with downward-firing 250mm passive radiator
Amplifier Power: 350W
Frequency Response: 22–180Hz
Inputs: Neutrik Speakon high-level, RCA low level
Finish: Gloss black, satin white
Dimensions: (W×H×D): 38 × 35 × 38cm
Price: £930, high level cable, £299
Manufactured by: Audiovector
Tel: +45 3539 6060
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