Roswell Pro Audio Mini K87 Condensor Microphone – Matched Pair We match Mini K87s to 0.5dB in sensitivity (measured at 1kHz), and about 1.5dB in frequency response, 50Hz–15kHz. Acoustic testing is done at Roswell HQ in northern California. The matching procedure uses a calibrated, proprietary low-diffraction speaker to produce a swept sine wave, which we [...]