The Cremona was significantly more sensitive than average, at an estimated 91dB(B)/2.83V/m. It should therefore work well with moderately powered amplifiers. However, that amplifier must still be capable of delivering a goodly amount of current. Even though the Sonus Faber's impedance magnitude remains reasonably uniform at higher frequencies, it drops to 2.8 ohms through the upper bass, with a cruel combination of 4.5 ohms and a -53 degrees electrical phase angle evident at 73Hz (fig.1).
Fig.1 Sonus Faber Cremona, electrical impedance (solid) and…