Напольная акустика — Raidho Acoustics C2.2

The C2.2 is a 2.5-way floor-standing loudspeaker from Raidho Acoustics, a Danish manufacturer producing its own tweeters and woofers. It belongs to the ceramic-cone C Series, a range that Raidho now shows among its archived earlier models. The maker describes it as a design built with the qualities of its smaller C-model standmount, but with a somewhat larger cabinet and an additional Ceramix driver.

Key specs that matter

Three drive units are fitted - a sealed ribbon tweeter, a 115 mm ceramic mid-bass driver and a 115 mm ceramic bass driver. The crossover to the tweeter is at 3 kHz with second-order filters. Raidho quotes a range of 40 Hz to 50 kHz, a sensitivity of 86 dB at 2.83 V and 1 m, and a nominal impedance above 4 ohm, and asks for amplification of more than 50 W. The cabinet measures 200 mm wide, 1,055 mm high and 470 mm deep, or 320 x 1,150 x 510 mm with its spikes, and each speaker weighs 43.5 kg. The cabinet is offered in black piano, walnut burl or a paint colour of choice, with the wood veneer and custom colours offered at extra cost.

Engineering and use context

Raidho explains that the added lower driver relieves the workload on the upper Ceramix unit, which gives deeper bass extension and more dynamic headroom than the standmount can offer. The Ceramix cones start as thin aluminium, and a liquid plasma process at very high voltage converts the outer skin of the metal into aluminium oxide ceramic. The finished diaphragm is a natural sandwich of thin, stiff ceramic skins on each side of a softer aluminium core that combines stiffness with good self-damping. The planar magnetic ribbon tweeter is hand-built in Denmark and works in a sealed chamber without any voice coil, which keeps its moving mass to about 20 milligrams on a foil 11 microns thick - roughly 50 times less than a conventional dome - and moves its breakup point to 82 kHz. A reflex port on the back panel loads the bass, and the narrow front carries only the three drivers.

Pairing

The maker reports very good results from small valve amplifiers, so the choice is not limited to large solid-state designs as long as the power minimum is met.

Alternatives

The Raidho C3.2 is another floorstander of the C Series in the maker's archive of earlier models, a three-way design with a ribbon tweeter, a Ceramix midrange and three Ceramix woofers.