Unity Audio have released a follow‑up to their first entry to the monitor market, the Rock, in the form of the Boulder. A three‑way design, the Boulder employs two low‑frequency drivers — a pair of seven‑inch woofers — crossed over at the relatively low frequency of 454Hz. The cones are of pulp construction with a 0.2mm aluminium‑foil coating, which stiffens the cones for a generous 30mm excursion.
Reproduction of the mid-range and high frequencies, meanwhile, comes courtesy of a dual‑concentric driver arrangement, comprising a five‑inch ring radiator with a folded‑ribbon tweeter in the middle. This configuration means that there are no time‑of‑arrival differences between the two drivers, in theory creating a wider monitoring sweet spot with less off‑axis coloration.
The amplifiers that power the drivers have been designed by audio guru Tim de Paravicini, of Esoteric Audio Research. There is one amp per driver (four per speaker), and they are all Class‑AB designs. The rear panel of the speakers house controls for overall level, a ±2dB high‑frequency shelf, and a mid‑band cut/boost.
All the above is built into a Baltic birch‑plywood cabinet with 18mm walls, with the front baffle being topped with a 30mm slab of Corian. A synthetic material, Corian was apparently used for its density, mass and rigidity, and the slab on the Boulder has been sculpted with highly radiused edges to reduce edge diffraction.
Unity Audio’s Managing Director Kevin Walker describes the speakers as having a “fast, accurate, detailed sound but with extended bass response, even more detailed mid-range and higher SPLs for larger rooms.”
Available from this Summer, the Boulder is expected to sell for around £5000 per pair.
