Напольная акустика — German Physiks Carbon MK IV

The Carbon MK IV is a floorstander from German Physiks, the German company whose loudspeakers are all built around its own omnidirectional DDD driver, hand-built at its factory in Germany. It is a luxury version of the Borderland MK IV, the company's most popular model, using the same crossover and cabinet but finished in high-polish carbon fibre under a deep clear lacquer.

Key specs that matter

One carbon fibre DDD driver sits on top of the cabinet, with a downward-firing 12 in woofer in the base. The DDD covers 190 Hz to 24 kHz. Frequency response of the system extends from 28 Hz to 24 kHz, sensitivity is 86.1 dB and impedance is 4 ohms. Amplifier power from 4 W to 160 W is specified. Two sets of WBT nextgen binding posts allow bi-wiring and bi-amping. The octagonal cabinet measures 404 mm wide, 1229 mm high and 404 mm deep and weighs 54 kg.

Engineering and use context

The DDD driver uses a cone of carbon fibre only 0.15 mm thick, mounted vertically with its outside surface exposed, so it radiates evenly through 360 degrees. Its moving mass is under three grams. It works as a pistonic driver at the low end of its range, then as a bending-wave radiator and finally in modal radiation at the top, which is how one driver covers almost seven octaves without a crossover in the midrange. The magnet sits at the apex, and the cone's throat plays into a small sealed enclosure. Each DDD takes a technician six hours to build, is pre-aged for 96 hours at high level, retested and matched into pairs. The woofer's sealed box connects by a narrow opening to a small upper chamber, which behaves as a Helmholtz resonator matched to the main box resonance and evens out the low end. The Carbon name dates from the Carbon Mk I, which differed technically from the Borderland Mk I, whereas today the finish is the only difference. The woofer is the same type as in the Loreley Mk III. The latest version has a new crossover with better bass integration with the DDD. The rigid octagonal cabinet avoids large flat panels. The Borderland on which it is based was introduced in 1992, and its concept has since informed the Unlimited and HRS-130 models. The DDD motor generates around 1.2 tesla in the gap, and the driver withstands being pressed by hand.

Pairing

The Carbon MK IV benefits from amplifiers of 100 W or more for high levels, although it works from low power. Because it radiates omnidirectionally, it needs space around it and suits rooms of 20 to 40 m2.

Alternatives

German Physiks' Borderland MK IV is the same design in conventional veneer and paint finishes.