MEASUREMENTS

I measured the Marten Oscar Duo’s farfield behavior with DRA Labs’ MLSSA system and a calibrated DPA 4006 microphone. I used an Earthworks QTC-40 mike for the speaker’s nearfield and spatially averaged in-room responses. I didn’t have the optional magnetically attached covers, so I didn’t use them. The Oscar Duo’s drive-units are protected with individual metal-mesh grilles.

My estimate of the Oscar Duo’s sensitivity was 85.3dB/2.83V/m, which is within experimental error of the specified 86dB/2.83V/m. Marten specifies the Oscar Duo’s impedance as 6 ohms, with a minimum magnitude of 3.1 ohms. My measurement indicated that the impedance magnitude (fig.1, solid trace) remains above 6 ohms for most of the audioband, with minima of 3.9 ohms between 35Hz and. The Oscar Duo has an EPDR of 2 ohms from 46Hz to 52Hz, 89Hz to 128Hz, and 3.7kHz to 8.6kHz, and the EPDR drops to 1.79 ohms at 100Hz and 1.82 ohms at 5.46kHz. The Oscar Duo should be partnered with an amplifier that doesn’t have problems driving impedances below 4 ohms.