Floor-standing speakers from the German company Elac.
The FS57 uses a traditional tweeter with a soft dome (2.5 cm). Two-way design with a d’Apollito speaker arrangement. The dual midrange / woofer speakers of the TT145 brand have a diameter of 145 mm, their diffuser is made of cellulose, and the voice coil is wound on a Kapton frame. The dome tweeter is covered with a mesh and has a cooling radiator on the back of the speaker. All speakers are made by Elac itself. The front panel has smoothed corners, and the decorative protective grille made of chipboard is firmly held on special copper-nickel pins and does not vibrate at high volume levels. Two bass reflexes are located in the lower part of the rear panel and have rounded edges.
The internal volume of each speaker is 41 liters. The developers recommend using amplifiers that can operate with a load of 4 ohms and have a power of 20 to 150 watts per channel. Despite the nominal impedance of 4 ohms, the minimum value reaches only 3.4 ohms, which is often characteristic of some 6-8 ohm speakers. The crossover frequency is 3 kHz, which is higher than in traditional two-way speakers. Thanks to the sensitivity of 90 dB / 2.8 V / the speaker can be used with not very powerful amplifiers.

Technical characteristics

Range 42 Hz to 23 kHz.
Number of bands: 2
Drivers: HF – 25 mm; 2 x MF / LF – 145 mm
Acoustic design type: bass reflex
Crossover frequency, kHz: 3
Sensitivity, dB: 90
Recommended amplifier power, W: 20-150
Frequency range, Hz: 42-23000
Nominal input impedance, Ohm: 4
Height, mm: 900
Width, mm: 170
Depth, mm: 250