Different phones have different “microphone maximums”: the maximum sound level, as measured in decibels (dB), that the microphone can record. For most phones this is around 100 dB. In order to record accurate sound level readings, AirCasters need to adjust the “microphone maximum” setting in the AirCasting app to match the specifications of their phone microphone. To do this, compare the readings from an external sound level meter with those from AirCasting. Then navigate to “settings” and adjust the “microphone maximum” until, through trial and error, the readings on your phone match those from the external sound level meter.  Those looking for extra precision may also want to adjust the “Offset at 60dB” setting.