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several positions in the room and compromise the equalization/attenuation
setting for the best possible sound. This may be done either with the equal-
izer or by aiming the tweeters of the main speakers differently.
Low frequency dips and peaks are room-related, and may be corrected to
some extent. Before you make any corrections, be sure to move the calibrat-
ed microphone around in the room to get a feel about how position dependent
the peaks and dips may be. When you know where in the room the peaks are,
at what frequencies they occur, and their amplitude, you may attempt to notch
them out with the equalizer.
Finally, play some program material with which you’re familiar and set the sys-
tem’s response to your taste.
EQUALIZING STAGE MONITORS USING THE RTA
The following procedure is a quick and easy way to minimize feedback in a
monitor system, and to get the best sound from your stage monitors. Place
the calibrated microphone a few inches to the side of the stage microphone.
This is so that the stage microphone doesn’t get in the way of the calibrated
microphone when picking up the stage monitor signal.
Turn on the pink noise generator, being careful not to blast the monitors.
Make sure that you turn down the input to the system, then increase the pink
noise level to a convenient measuring level. Use just enough level from the
RTA to overcome any ambient room noise
Turn up the gain on the stage microphones until they begin to feed back. You
will see the feedback frequency displayed in the RTA window.
If you’re using more than one stage monitor, find the one that feeds back the
worst and use that monitor to find the feedback nodes. Notch out the offend-
ing frequency with your equalizer. Increase the gain on the stage micro-
phones until you observe another feedback node. Notch out this frequency.
You may attempt to find and notch out other frequencies, but after the third
frequency, this will become unproductive. You’ll find that in making deep
notches to reduce the feedback, the sound quality of the monitor system is
reduced.
Using pink noise, attempt to flatten the response of the monitors. If you are
trying to achieve the highest possible sound level before feedback from the
stage monitors, the sound quality of the monitor system will be reduced. The
best sound from the monitors is usually obtained with a "compromise setting"
on the equalizer. The goal of this type of setting is to modestly reduce the
feedback nodes, but still allow good sound quality from the monitors.
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