The Avalanche 12in active sub-woofer, previewed at AES, is shipping now. Primarily designed to compliment Unity Audio’s existing Rock and Boulder models, Avalanche transforms them into three way and four way systems respectively. It can also be used with other manufacturers monitors.

Like the Rock and Boulder, the Avalanche is a sealed cabinet maintaining fast detailed transients and accurate bass reproduction. Internally the cabinet is split into two chambers with a dividing bracing partition and restrictive membrane feeding the second chamber. The cabinet is built from 24mm ply, with a laminated baffle some 42mm thick. Internal damping is achieved with a dense rubber lead substitute attached to the walls, thereby reducing cabinet resonance.

The Avalanche has a 12in downward firing woofer keeping a low centre of gravity thus reducing vibration and movement. Unity Audio’s aperiodic vent enables extended low frequency (down to 22Hz) as if the relatively small enclosure has a larger volume.

Amplification is by two Rock/Boulder low frequency amplifiers running in parallel giving a total power of 150 RWNBSW. These are mounted with the output transformers onto a heat sink isolated via rubber anti-vibration mounts. Burr Brown ICs are used throughout the custom input crossover, with the Burr Brown OPA627 op-amp specified to maintain signal integrity in critical audio paths.

The crossover low pass utilises a fourth order filter, while the high pass utilises a second order filter.

For teaming up with the Rock or Boulder, two factory presets are provided for each model, the ‘R60’ is for the Rock, setting the crossover at 60Hz, while the Boulder ‘B50’ preset sets it at 50Hz. If situations like acoustics, positioning or personal preference dictates something other than the presets provided, then both low and high pass filters can be set independently in Vari Mode. This will, if desired not only allow different crossover frequencies, but also controlled and independent overlapping to create the perfect crossover.

Other controls include input gain, balanced XLR I/O and a 180-degree phase reverse switch. Included is a foot-switch bypass pedal as standard. This allows the Avalanche to be bypassed and transmits the full frequency range to the satellites without any additional electronic circuitry in the audio path.

The Avalanche sits on four large heavy-duty rubber feet to reduce vibration, and isolate it from the floor.

www.unityaudioproducts.co.uk