There’s more going on inside this soundbar than you might expect. Behind the the Sub Zero's grille are eight speaker drivers in total (six 40mm long throw full range and two 19mm aluminium dome tweeters), two of which are the aforementioned Vector Firing Side Drivers that enhance stereo and surround modes by widening the sweet spot and theoretically creating a more expansive soundstage.
Meanwhile, two ‘Ultra Bass’ passive woofers are included in place of a separate subwoofer, powered by a new Class HD amplifier. This is said to be more efficient that conventional analogue and Class D amps, while its compact design cuts down bulk apparently without compromising on power.
Also at play inside the Sub Zero is Fractal Expansion, an advanced processing technology that creates a wide soundstage with a two-channel signal, creating virtual centre and surround channels in a bid to replicate the experience of a real surround system. This mode can be turned on and off by hitting the Surround button on the remote.
Thankfully, all this impressive-sounding audio tech adds up to an assured performance. We rigged up a Blu-ray player via its analogue outputs with Super 8 in the tray and what struck us straight away is the sheer power on offer, which makes the 2 x 16W (RMS) rating seem very modest indeed.
The movie’s train crash scene, for example, is handled with plenty of dynamic thrust and drive, while the built-in bass drivers do a great job at conveying the impact of those massive carriages careering into each other. The speakers have no trouble filling a room, delivering a loud yet comfortable listening experience that will give your TV’s own speakers a serious case of audio envy.
The Fractal Expansion and side-firing drivers do a decent job at widening the soundstage too. We’re not talking Yamaha-quality sound beam surround sound, but the stage is certainly more spacious and involving with it switched on. Effects fly around in the spaces either side of the TV, making everything seem more open and expansive.
On top of this, the Roth Audio Sub Zero locks dialogue tightly to the centre of the front soundfield, allowing voices to cut through busy scenes with no trouble at all. We’re also impressed by the clarity of high frequencies, which again helps the sound feel airy and detailed – there’s no sense of soundtracks feeling boxed-in or compressed, which is hard to achieve on a soundbar with limited cabinet volume.
With a digital TV receiver rigged up, TV material also sounds clear and powerful without making more dynamic material like adverts sound harsh or distorted. If there’s a weakness it’s with music playback – the Sub Zero lacks the sensitivity and neutrality to kill you softly with its song, but to be fair that’s not its main focus anyway.
With its tasteful, compact design, easy operation and dynamic sound quality, Roth’s Sub Zero is a fine soundbar at a great price. Even without a subwoofer it delivers a deep, powerful sound with decent detail and clear dialogue handling, and although its surround processing isn’t a patch on Yamaha’s Digital Sound Processors, it achieves a pleasing sense of width and space.
It’s also easy to install and use, and thanks to the choice of wall or tabletop mounting – not to mention the lack of a subwoofer – there’s plenty of flexibility when it comes to placement.
Bear in mind though that it’s a fairly simple unit with sparse connections, no HDMI and no Dolby/DTS processing. It’s designed as an add-on to your TV and not really ideal for those who want to run lots of sources through it – if that’s what you had in mind, you’re better off looking at a more comprehensive soundbar system like LG’s BH5521A.