- Written by Chris Groppi
- Published on 26 November 2012
Design of the Crystal Cable Arabesque Speakers
The first thing you'll notice about the Arabesque Mini is the unique cabinet shape. The multi-faceted curved horn shaped enclosure footprint of the speaker is the shape it is to break up any resonant modes inside the cabinet. Standing waves can selectively reinforce or diminish sound at specific frequencies, when the cabinet dimensions are multiples of ¼ the sound's wavelength. The shape of the Arabesque Mini cabinet is such that there are no parallel sides to the enclosure to create resonances (excepting the top and bottom panels). Furthermore, the spacing between the cabinet facets is constantly changing, which also reduces the presence of internal standing waves. The B&W Nautilus line uses similar ideas for their high frequency driver sub-enclosures, but only the limited production Nautilus model used that type of shape for the whole enclosure. The top and bottom panel resonances only come into play at frequencies below about 250 Hz.
The case itself is made from several machined aluminum panels, fastened together internally using an aluminum skeleton. Small oval ports are located at the narrow end of the cabinets. The only visible fasteners are on the speaker's bottom panel. Like its glass big brother, the cabinet uses no internal damping whatsoever, with a bottom mounted crossover. The drivers are very expensive Scan Speak models, the Illuminator 5.25" woofer and a positive dome Beryllium tweeter. A rear panel switch allows the user to tune the tweeter response to the room and personal preference. A single pair of beefy 5-way binding posts are provided, so bi-wiring or bi-amping is not an option. A simple 2nd order low-Q crossover is used between the woofer and tweeter at 2 kHz. The aluminum cabinet material, like glass, has a very high soundspeed. This means mechanical resonances will be low in amplitude and at high frequencies. Also, the cabinet will react very quickly to any transients. With no damping, this type of design relies on mechanical rigidity and carful design to control resonance. Many speaker designers allow resonances to occur and then soak them up with various types of damping materials. The Arabesque Mini uses just the opposite approach: let as few resonances occur as possible, and don't try to stop them. The idea is to create a "fast" loudspeaker that will let the full impact of transients though. Any damping material in the cabinet, or a soft cabinet material will slow and dull desired musical signals just as well as resonances.
This is all well and good, but the ideas do have a down side: cost. The Arabesque Mini is a very expensive speaker, particularly for its size. The cabinet is very complicated to make and assemble. Your money does buy you excellent fit and finish, though. The quality of machining and assembly in the cabinet is excellent. The drivers are the best money can buy, as are the binding posts and internal wiring. My speakers came with very nice optional stands made of four solid Lucite rods and a synthetic stone base that all screws together. I think I would have preferred the look and rigidity of aluminum pillars, but the Lucite did fit the speakers into the Crystal product line better. The stands are available in two heights depending on how tall your listening seat is. Feet are provided if you want to actually put these on a bookshelf, but I don't understand why anyone would want to do that.
The asymmetrical shape of the speaker gives you two setup choices: pointing the narrow end of the cabinets in or out. I found through experimentation that narrow end out worked best for me and my room, with the speakers strongly toed in toward the listening position. The setup was roughly an equilateral triangle to the listening position with 10 foot sides. My room requires that the speakers be placed well out into the room, over 3 feet from the rear and side walls. I knew this would have a negative effect on bass response, but would probably result in better imaging and soundstaging. I also used the short stand pillars, as that placed the speakers closer to ear level when I sat in my listening room's sofa. I used the speakers for light home theater listening duty for a few weeks before getting down to the review.