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Bedrock SMxx operating manual
© Bedrock Audio BV, 2019
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Once a measurement has started, each combination of the above settings is measured si-
multaneously. However, not all of these combinations are displayed: only two level meas-
urements are displayed at the same time. Each of these two levels is shown in its own bar
graph and its own digit field. The red graph corresponds to the red field, the blue bar graph
to the blue field. You are free to select which level to display in each of the two fields. Tap
the “set” button in the level field to choose time weighting, frequency weighting, max hold
and time integration settings for the corresponding field.
The SMxx will warn you if the signal level is outside the linear range of the microphone.
This occurs if the signal level is too low in comparison to the noise floor of the microphone
(underrange ) or if it approaches the maximum acoustic level that the microphone can
handle (overload ). Both types of range warnings are shown as a warning label next to the
corresponding measurement value.
Range warnings are shown in both level fields if the signal level is either too low or too high
(such as in this example).
The limiting factor for the overall dynamic range of the measuring system is
usually the microphone. If the standard microphone is replaced by a micro-
phone of a different type, the displayed overload and underrange warnings
may not be reliable. Please check the Bedrock audio online support pages
to find out for which microphone types (besides the standard microphone)
range warnings are supported. If you replace the microphone, it may be nec-
essary to patch the system firmware with a specific update package.
For MAX, EQ and PK measurements, the range warnings will be displayed from the mo-
ment the underrange or overload condition occurs until the measurement is restarted. For
FAST and SLOW measurements, the range warning will disappear once the overload/
underrange condition has passed.