Dynaudio AIR 15, Reference Manual

Page: 125 / 129

Appendix: Acoustics
Dynaudio Professional AIR reference manual – 2014-09-28 122
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.
►
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.