I used DRA Labs’ MLSSA system and a calibrated DPA 4006 microphone with an Earthworks microphone preamplifier to measure the Audiovector QR 7’s farfield frequency response and dispersion. I used an Earthworks QTC-40 mike for the nearfield and in-room responses and Dayton Audio’s DATS V2 system to measure the impedance magnitude and electrical phase angle.
Audiovector specifies the QR 7’s anechoic sensitivity as 90.5dB/W/m. My estimate was slightly lower, at 88.7dB/2.83V/m, though this is still higher than average. The QR 7’s impedance is specified as 6 ohms. The impedance magnitude (fig.1, solid trace) varied between 5 ohms and 12 ohms in the midrange and treble, with a still drops below 3 ohms between 57Hz and 140Hz, with a minimum value of 1.8 ohms at 76Hz. As long as the partnering amplifier can drive 4 ohms, the QR 7 shouldn’t present it with any drive problems.