Напольная акустика — Cessaro Horn Acoustics BETA II

BETA II comes from Cessaro Horn Acoustics in Germany as a 4-way horn tower, built around a large bass horn and part of the brand's modular line. In its F4 form it can be upgraded to the GAMMA II-F8 at any time, which protects the investment for owners who later move to a bigger space.

Key specs that matter

Efficiency is 105 dB at 1 W/1 m and nominal impedance is 8 ohm. The stated frequency range covers 30 Hz to 45,000 Hz, maximum output is above 124 dB and power handling is 60 W. The main unit is 176 cm high, 58 cm wide and 84 cm deep, and the active bass horn measures 105 cm in height and 100 cm in width. Weight per channel is 750 kg in plywood or 950 kg in composite construction.

Engineering and use context

The crossover networks use high value capacitors of pure silver MICAS type, and the internal wiring throughout is pure silver cable. Cabinets are hand built by German craftsmen to coach-building standards. Horn shells are double walled and filled with a heavy polymer of set density, the throat is a solid one inch aluminium ring, and the mid horn alone of a Beta model weighs more than 100 kg. The bass section uses four 16 inch TAD alnico units in a backloaded or frontloaded horn, with an 18 inch field coil option. Two special solid state power amplifiers, each with a 1200 W transformer, drive this section. The low-mid band is an 11 inch alnico driver in a spherical composite horn, a 2 inch alnico compression unit fitted with a beryllium membrane covers the midrange from another composite spherical horn, and a 0.5 inch cobalt treble compression unit, again beryllium, sits in a 9 cm milled spherical horn. The maker lists a room above 33 m2 and a listening distance beyond 3.5 m, so the system does not target the typical 20 m2 living room. Composite horns come in unlimited colours and several wood veneers are offered for the cabinets. Founder Ralph Krebs had the spherical horn shape developed over 2.5 years in custom simulation software, with the mouth edge modified to soften the wave there.

Pairing

Because the bass horns carry their own amplification, the owner's amplifier only feeds the upper three bands, and the maker simply asks for high quality, fast amplifiers. The floor has to carry the full mass of each channel.

Alternatives

Cessaro GAMMA II is the 5-way tower in the same modular range with up to eight bass units per side and 107 dB efficiency.