56
Bedrock SMxx operating manual
© Bedrock Audio BV, 2019
57
To start calibrating, apply the calibrator to the microphone and press “start.” Do not worry
if the reference level shown is incorrect; you can change this after the measurement. An
octave band spectrum will be shown while the equivalent-continuous A-weighted sound
level is measured. Once this measurement is finished, the Bedrock SMxx will show the
results.
The new calibration factor (sensitivity adjust) of the device is shown, as well as the origi-
nal calibration factor as currently used in the device. The differences between the old and
new value are typically small (less than 5 dB), unless you have connected a different signal
source or microphone than the device is currently calibrated for.
If you already know the calibration factor for your microphone, you can enter it manually.
The second screen of the calibration module has two editable fields: “acoustic calibration
factor” and “electric calibration factor.” The acoustic calibration factor is the same param-
eter that is normally measured with a calibrator.
The second screen lets you enter calibration factors manually.
The electric calibration factor cannot be determined automatically with a calibrator; it can
only be changed by hand. This parameter modifies the sensitivity of the XLR input for
electric measurements (e.g. AC Volt measurements). Recalibration should rarely, if ever, be
needed; exercise great caution when adjusting this value.
We recommend that you verify any new calibration in the SPL meter module. Re-apply
your calibration signal source, and check that the correct reference level is measured.
Once you press “save,” the measured calibration factor is committed perma-
nently to the device’s non-volatile memory. This overrides earlier calibra-
tions. Do not manually change calibration factors unless you are absolutely
certain that this is what you need to do. All measurements will be affected.