Wisdom Audio DCAB-1 - Manual (Page 30)

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The Calibration Process
What follows is a methodical process for correcting the anomalies found in your
specific acoustic environment. It assumes that everything is properly connected
and that your computer is communicating with the DCAB-1 via TeraTerm Pro
(or a similar terminal program).
One important note on using pink noise to calibrate systems: your ears hear
things differently than an omnidirectional microphone. Therefore, it is essential
that we adjust the speakers to fit a curve that takes these differences into ac-
count.
Specifically, our ear/brain mechanisms differentiate between early arrival sounds
and subsequent reverberation; what we perceive is a complex combination of
the two. By contrast, the microphone lumps all of this information together.
Since the later reflections have lost much of their high frequency information
through absorption, trying to make the overall mix measure “flat” will make the
direct sound far too bright.
Our founder, Tom Bohlender, has personally calibrated many Wisdom Audio
systems, in a huge variety of rooms. In his considerable experience, the target
curve you should be shooting for when using pink noise calibration looks some-
thing like the following:
In short:
±3 dB from about 30-100 Hz •
smoothly shelf down by about 3 dB, then ±3 dB to about 600 Hz •
smoothly shelf down another 3 dB, then ±3 dB to 20 kHz •
a little extra energy below 30 Hz (as measured by pink noise) is fine •
Note that this target curve is specific to planar magnetic line sources such as the
Wisdom Audio Adrenaline series of loudspeakers. Also, if you want a little more
movement of your pant legs, you can increase the 20-30 Hz range a couple dB
more without unduly upsetting the tonal balance of the system.
Important The microphone will capture any and all noise in the environment.
We live with many low frequency sounds that we tend not to
notice, including vibrations from passing traffic, air conditioning
compressors, furnaces, and refrigerators. All such low frequency
rumbles will be picked up by the microphone and displayed on the
RTA. To get accurate results, do everything you can to quiet the
environment: close the windows, turn off heavy equipment in the
home, and in extreme cases, do the calibration in the early morning
on a weekend, when traffic noise is at a minimum.