Полочная акустика — Buchardt Audio S400 MK3

The S400 MK3 is the third generation of the S400 stand-mount from Buchardt Audio, the Danish direct-sale loudspeaker company. First shown as a prototype in 2016, the S400 became a cornerstone of the Buchardt range. The MK3 is described as a ground-up redesign, with only the binding posts carried over from the MK2. Buchardt supports it with a 10-year warranty.

Key specs that matter

It uses a 7.5 in SB Acoustics Satori Papyrus paper-cone woofer with a neodymium motor and a custom 26 mm aluminium dome tweeter in a 7.5 in aluminium waveguide. The crossover sits at 2.2 kHz. Frequency response starts at 33 Hz, sensitivity is 88 dB and impedance is 4 ohms, with more than 30 W recommended. The cabinet measures 392 x 198 x 280 mm and weighs 8.5 kg.

Engineering and use context

The woofer has a BIMAX spider, a CCAW voice coil on a non-conducting fibreglass former, a vented pole piece and a copper sleeve that lowers inductance. It offers 65.5% more displacement than the MK2's 6 in driver, while the cabinet has grown by only 18% in volume. The MK2 used a passive radiator, and the MK3 changes to a rear-ported bass reflex design. Buchardt recommends at least 5 cm of clearance from the rear wall so the port can breathe. The tweeter moves from the MK2's 19 mm soft dome to a 26 mm aluminium dome, driven by a matrix neodymium motor with copper in the magnet system. Its back chamber gives a low resonance, which allows a quasi-first-order tweeter filter, and the dome is bonded directly into the waveguide, which controls directivity, keeping the response consistent on and off axis. This gives a more even in-room response and a wider listening area, which Buchardt considers especially useful in untreated rooms. The crossover, developed with Jantzen Audio, has a simpler topology than the MK2's, with air-core inductors up to 1.6 mm wire, Jantzen Cross Cap polypropylene capacitors and Superes wire-wound resistors. The first S400 was the first hi-fi speaker Buchardt developed with a Klippel Near Field Scanner. The original S400 used a deep waveguide that extended below the woofer, and the waveguide principle continues in the MK3. Finishes are black or white, with walnut and natural wood veneers at extra cost. Foam port plugs are supplied for reduced bass output.

Pairing

Any amplifier stable into its low nominal load suits the S400 MK3, ideally with 60 W per channel or more. Its bass extension from a compact box suits rooms of 12 to 30 m2.

Alternatives

Buchardt Audio's S400 MK2, introduced in 2021, is the previous generation with a 6 in woofer and a passive radiator.