Efficiency: 85 dB/W/m (Yamaha specification of 88 dB related to 8 ohms, thus too high by 3 dB)
Frequency response: 26 - 40000 Hz (-10 dB)
Transition ranges: 750/4500 Hz
Impedance: 6 ohms (wrong specification from Yamaha. The minimum impedance according to Yamaha is 3.5 ohms, so the nominal impedance according to the standard is 4 ohms)