Measuring Sound Pressure - Dynaudio AIR 15 Reference Manual

Measuring sound
pressure
Using a sound level meter or microphone
If you are used to performing acoustic measurements,
you probably already own a sound level meter. A
sound level meter can be used for the level calibration
of the monitors.
If you do not have a sound level meter, there still is
another possibility: Use an omni-directional micro-
phone (this is also called a pressure microphone). A
studio condenser microphone is normally preferred, but
the microphone must not be too big. A simple clip micro-
phone can be used, as it does not influence the sound
field. In any case, the microphone should have a flat
frequency response.
Place the microphone on a stand positioned at
►
the listening seat. Leave the microphone pointing
upwards to avoid sound pressure build-up in front
of the diaphragm and to provide equal conditions
for monitors in all directions.
Connect the microphone to a mixing desk or a
►
recording machine that has a meter built in.
Play back a track containing pink noise from the
►
Dynaudio Professional AIR monitors test signal
collection, or use one of the other tracks that you
have used for monitor setup and calibration.
Dynaudio Professional AIR reference manual – 2014-09-28
Adjust the gain on the microphone channel until
►
the meter deflection reaches a point 10 dB below
full scale. This is now your reference for following
measurements.
Make sure that you have marks on the scale that
makes it possible to read steps of 1 or 2 dB on
either side of the reference deflection.
If 10 dB below full scale is not an adequate point
on your meter, you may choose another one – just
be sure to have a reading on a adequate resolu-
tion.
If you use this microphone setup as described, it can be
used for comparing levels between individual monitors.
Absolute sound pressure levels can be measured if
you...
1. are using a well-calibrated microphone channel
and
2. know the sensitivity of the microphone.
Appendix: Acoustics
122