I understand SPL and the conversion to other units, but I haven't been able to find the distance used when measuring microphone sensitivity. Your example (Tech Bulletins; Mic Sensitivity) of -75 dBV/microbar for example, says "microbar" indicates the mic was tested with 74 dB SPL, but at what distance? If the answer is 12 inches, can I assume that any mic rated in dBV/microbars was measured at 12 inches? I have to calculate preamplifier gain, and would appreciate your help.
Our standard distance is 24", unless otherwise noted in the data sheet. The 74 dB SPL is measured at the mic diaphragm, not the source loudspeaker.
No, you cannot assume that any mic rated in dBV/microbar was measured at 24", but you can assume that one microbar was measured at the mic diaphragm.