Unity Audio Speakers from Kazbar Systems

The next active professional monitor following on from the The Rock, is the new larger 3 way Boulder, due to be available at the end of May.

Unity Boulder Speakers from Kazbar Systems

Unique Cabinet Construction

The Boulder shares some of the same interesting material and designs of The Rock, such as a Baltic Birch plywood cabinet instead of commonly used MDF, but this time 18mm instead of 12mm as used in The Rock. The cabinet dimensions are 368mm deep x 256 mm wide x 549mm high.

To add density, mass and rigidity to the design, the front baffle is manufactured from Corian, like The Rock, and bonded to an internal wooden baffle, but the Boulder uses a huge 30mm slab of Corian instead of The Rocks 12mm and with large radius edges and scalloped sections either side of the coaxial mid/tweeter unit to reduce reflections.

The Rock has gained a fantastic reputation for it’s super accurate smooth, fast, deeper and detailed bass response, partly due to it’s closed cabinet design, and The Boulder continues with this closed cabinet design. An ingenious bracing system has also been designed to stop cabinet flexing.


Unlike other 3 way monitors, The Boulders 2x180mm (7” ) woofers are employed purely for bass reproduction, and they are the same woofer model as used in The Rock, the crossover point being 454Hz. This will increase low frequency extension and achieve higher SPL’s. Each woofer has a 0.2mm aluminium foil chemically bonded to a rigid pulp fibre cone. This reduces harmonic anomalies and permits +/- 15mm of woofer travel producing accurate low bass frequencies.
The use of Aluminium bound to a pulp fibre cone insures that the woofer cone will remain symmetrical at all frequencies, producing a long life for the woofer element and full accuracy of the driver through its life. Something few other materials can claim.

Unique Coaxial Midrange-Tweeter

A new dual coaxial Midrange/Tweeter is employed, another unique feature of The Boulder. This very special new unit is a combination of a 5” midrange ring radiator and a concentrically arranged folded ribbon tweeter. This design realizes the vision of an acoustic point source eliminating phase issues This facilitates an optimized acoustic power response and results in a homogeneous and very wide sound dispersion angle which provides for a new kind of relaxed but very precise reproduction.

Custom Discrete Amplification By E.A.R

The Boulder uses the same custom designed Tim de Paravacini Esoteric Audio Research Class A/B amplifier modules from The Rock, but a total of four amplifier modules are used, one for each drive unit. A high frequency shelving EQ with a +/-2.5dB control, and mid band cut/boost control as well as an overall level control with also be accessible on the rear amplifier panel.

“ I’m very excited about the new Boulder, the team involved, acoustician Kevin Van Green and Tim de Paravacini and Elac have helped to create and produce something really special. Field trials with numerous UK engineers and producers have confirmed this. The continuing association with Elac who have allowed us to use their coaxial mid/hf unit, which from the company’s range of drivers is their jewel in the crown. Like The Rock, this new model will boost true fidelity, fast, accurate detailed sound but with extended bass response, even more detailed mid range and higher SPL’s for larger rooms.” Kevin Walker-Unity Audio LTD MD.

Estimated price £5,000 inc VAT a pair. Available May/June.


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