Напольная акустика — Fischer & Fischer SN/SL 570

The SN/SL 570 is a slate-cabinet three-way passive tower by Fischer & Fischer, a German manufacturer based in Schmallenberg that makes all of its loudspeaker enclosures from natural slate. In the maker's line-up it follows the SN/SL 470 M and is paired with a revised SN/SL 570 M, below the SN/SL 670 and the four-way models. Two finishes exist, SN with the unpolished stone face and SL with the slate polished and then painted in any RAL tone or a car colour on request.

Key specs that matter

Bass is produced by two 220 mm Fischer & Fischer cones whose membranes are a carbon paper foam sandwich. Two further cones of 180 mm run the midrange, built from carbonized paper laminated with carbon foil and fitted with aluminium phase plugs. For treble the speaker uses an Air Motion Transformer that Mundorf produces to the brand's own specification. Rated response is 28 Hz to 27,000 Hz within a 3 dB window, with 4 ohm impedance, 92 dB sensitivity at 1 W and 1 m and a 112 dB acoustic pressure ceiling. The stone cabinet measures 1250 x 240 x 400 mm and, standing on its floor system, 1295 x 345 x 455 mm. Each unit weighs 129 kg.

Engineering and use context

A bass reflex principle is used, and the dividing network combines 1st and 2nd order slopes with correction for phase and impedance. Walls are 20 or 23 mm of low-resonance slate. Fischer & Fischer argues that the layered rock and its great mass let the full energy of each driver move the air instead of setting cabinet panels in motion, which also allows enclosures of domestic proportions. Its slate, the company says, took nearly half a billion years to form. Fischer & Fischer also offers owners the option of updating their speakers with newer technology years later. The supporting frame is aluminium and can be levelled. The company also credits the mass reactance of the stone with holding the baffle still so it does not move along with the tweeter diaphragm, and it says chassis and components are bought from leading makers on the world market.

Pairing

A bi-wiring panel with rhodium plated 63 A terminals and pure silver jumpers accepts either a single cable run or two runs, one per section. The partnering amplifier should be specified to drive the low nominal impedance comfortably.

Alternatives

The Fischer & Fischer SN/SL 570 M, a three-way tower, has a 4-chamber slate cabinet, a rated low end of 24 Hz and a weight of 115 kg.