The SF-2MP Active Ribbon Microphone from Royer is a matched pair of SF-2 microphones.
Designed primarily for classical applications and acoustic instruments, the SF-2 combines high-quality audio performance with active electronics for high output. The SF-2's output of -38 dB puts its sensitivity on par with that of phantom powered condenser microphones, allowing it to be used with a wide variety of mic pres regardless of gain characteristics. The mic uses custom designed FETs to deliver quiet operation, with self-noise of lower than 18 dB. The SF-2's magnet/pole piece transducer structure gives a wide, uniform frequency response and the 1.8-micron ribbon element is designed to deliver accurate transient response. The mic also is designed to provide accurate frequency response regardless of the angle of sound striking the ribbon and for low off-axis coloration.
The electronics in the SF-2 provide the correct load to the ribbon element at all times, so its performance is never compromised by the effects of improper loading and regardless of the input characteristics of the mic-pre. Due to its low impedance output, SF-2 can be used on long cable runs with minimal signal loss. In addition, the mic is designed to resist ribbon element damage by phantom power, electrical glitches or miswired cables.