Floorstanding loudspeakers — Fischer & Fischer SN/SL 570 M

The SN/SL 570 M is a passive floorstanding three-way model produced in the Schmallenberg, Germany workshop of Fischer & Fischer, a brand known for housing its drivers in natural slate. It is listed next to the standard SN/SL 570 and below the SN/SL 670 in the company's catalogue. Customers may order the SN version with a natural slate surface, or the SL version, which is polished and varnished in any RAL colour.

Key specs that matter

For bass, the speaker has a pair of 220 mm Fischer & Fischer cone drivers with carbon paper foam sandwich diaphragms. Two 180 mm midrange cones combine carbonized paper with carbon foil in a sandwich construction and each has an aluminium phase plug. Treble is reproduced by an Air Motion Transformer custom built by Mundorf for Fischer & Fischer. The published range is 24 Hz to 27,000 Hz at plus or minus 3 dB, impedance is 4 ohms, sensitivity reaches 92 dB at 1 W over 1 m and maximum acoustic pressure is 112 dB. The slate enclosure is 1245 mm tall, 275 mm wide and 400 mm deep, and with its feet the outline becomes 1290 x 380 x 455 mm. The weight is 115 kg.

Engineering and use context

Internally the cabinet is split into a 4-chamber system and loaded as a bass reflex design. The crossover uses 1st plus 2nd order filters, corrected for phase as well as impedance, and the maker describes its networks as optimized and selectively separated. The slate walls are 20 and 23 mm thick. Fischer & Fischer attributes the choice of stone to its layered structure and very high mass, which the company says keep the cabinet from vibrating and allow living-room friendly dimensions. The floor system is aluminium, anodized either black or silver, with levelling adjustment. Fischer & Fischer notes that its slate formed over almost 500 million years, and that the heavy stone keeps the tweeter baffle from resonating with the membrane.

Pairing

Bi-wiring is provided through rhodium plated 63 A binding posts, allowing one pair of cables or two separate runs per side. Choose an amplifier rated for the low nominal load. According to the brand, earlier speakers can be upgraded with current technology years after purchase, and it states that its chassis and parts come from top suppliers on the world market.

Alternatives

The Fischer & Fischer SN/SL 670 is a three-way floorstander built in a two-part slate cabinet that weighs 129 kg.