Owners Manual

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DRAWMER
MONITOR CALIBRATION
Whether you are installing one, two or three sets of speakers it is imperative that
your system is calibrated, not only to centre the stereo image and to ensure that all
speaker levels are the same, but also to ensure that you are mixing your music at
industry standard listening levels. The MC3.1 can calibrate the speakers of any
system as it has individual rotary level trim controls for every speaker attached
(found on the underside of the product).
The following method is by no means the only way to calibrate your system, and a
quick look on the internet will soon find many others, but is a good starting point.
Before beginning the procedure there are a couple of things that you will require:
Sound Pressure Level (SPL) Meter:
Unfortunately, it is virtually impossible to measure the level
of sound from each speaker by ears alone. A good
instrument that does a more accurate job is a Sound
Pressure Level meter.
SPL Meters come in two varieties: with an analog meter or
with a digital display, either works well, just choose your
preferred type. You can purchase an SPL meter from most
electronic stores, or search the internet in stores such as
Amazon, with prices ranging from £25 to £800. Radio Shack
is a good source for reasonably priced SPL meters in the
USA, though to get better results, you may consider a more
expensive SPL meter, such as Galaxy, Gold Line, Nady,
etc.
The ideal meter should have the industry standard “C-
weighted” curve, slow setting. Refer to your meter’s manual
to learn how to select these settings.
If all else fails there are iphone/Android apps that claim to
be SPL meters - whilst these are nowhere near the quality
of a dedicated meter they are better than nothing.
Test files:
Test tones can either be generated through your DAW (such as the Signal
Generator plug-in in Pro Tools), but you can also download test/calibration
files from the internet if you search around: wav files are preferred to mp3’s
due to the compression/limited frequency range of mp3’s. You can also
purchase good quality reference CD’s/DVD’s from various stores.
The tones required for this calibration process are:
1. 40Hz to 80Hz bandwidth limited pink-noise file recorded at -20dBFS.
2. 500Hz to 2500Hz bandwidth limited pink-noise file recorded at -20dBFS.
3. Full-bandwidth pink-noise file recorded at -20dBFS.