Using The Power-Q Automatic Room Eq; What Is Automatic Room Eq?; How Automatic Room Eq Works; Reference Microphone Choice - SABINE Power-Q Operating Information Manual

means of fast, automatic equalization, calculated by the POWER-Q on the basis of measurement
of acoustic energy heard at a reference microphone, and designed to provide a neutral, repeat-
able "starting point" for additional program equalization and signal processing. The EQ curve
calculated is designed to make the response curve heard at the microphone as flat as possible,
compensating for room acoustics and the frequency response of the sound system components.
1. Environmental Artifact Removal (EAR). First, the POWER-Q's Environmental
Artifact Removal function measures the frequency response curve of ambient noise in the room,
as heard by the reference microphone placed in the optimal reference position. Most acoustical
environments exhibit some degree of unwanted sound artifacts (e.g., air conditioner rumble,
running fans). The POWER-Q measures this energy and calculates a temporary "noise curve."
2. Room Analysis. Second, the POWER-Q measures the energy of pink noise played
through the sound system at the reference microphone. The POWER-Q will automatically boost
or cut frequencies to achieve as flat a room response as possible when the tones are played
through the sound system and heard at the reference microphone. This flat room response is
abbreviated "EQ RM" and is meant to serve as a consistent starting point for further adjustments.
Note that the frequencies heard and analyzed when the pink noise is played discount the "noise
curve" and represent only the interaction of audio played through the sound system and impacted
by the specific acoustics of the auditorium.
Note that the accuracy of measuring and compensating for ambient noise will improve when both
noise level and noise frequency are relatively constant. For best results, minimize or eliminate any
ambient noise sources when possible.
use, and the acoustics of the environment are important considerations for performing an
acoustic analysis such as the POWER-Q's Automatic Room EQ. This is potentially quite a
complex subject and a complete discussion is beyond the scope of this manual. Any attempt to
equalize an acoustic environment will be subject to compromises and response variations from
one location to another. Nonetheless, it is possible to make adjustments that will improve the
system/room response for most if not all audience listening areas.
Ask 20 experts and you're likely to get a variety of opinions and strategies about room equaliza-
tion; suffice it to say that experience and your unique skill as an engineer will play a significant role
in your choice of mic type, model, and placement. For a more complete discussion on this
subject, please refer to John Murray's excellent article, "Doing the Right Thing" in the July/August
1997 issue of LIVE SOUND! International.
For those of you who may want a relatively quick summary of what to consider about this topic,
read on.
Let's first consider the type of microphone to be used.
First of all, the frequency response of the microphone should be as close to flat as possible, within
"1 dB from flat across the audible frequency range (20 Hz to 20khz), and should exhibit flat
response at both loud and quiet sound pressure levels. The greater the deviation from flat
response by the microphone, the greater the deviation from flat response your system may exhibit
when using the mic to set EQ.
Sabine's unique AUTOMATIC ROOM EQ feature is simply a
Sabine's Automatic Room Equalization works in two steps:
Microphone placement, the type of microphone you