Art XL 231, Руководство по эксплуатации

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ART XL 231 Dual 31 Band, 1/3 Octave Extended, Long Throw, Professional Equalizer
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overtones of guitar are intensified in this octave.
Upper Highs: 10KHz to 20KHz
The upper limits of hearing fall within this octave. Since only the upper harmonics of
some instruments are in this range, you may often cut these bands to reduce hiss
without affecting the overall sound quality. Brightness of cymbals and synthesizer
harmonics may also be controlled. Boosting this range can add “air” to the instruments
being equalized.
PA Systems – power amp operating levels
It is common to use 31 band equalizers for FOH (Front of House) as well as monitors.
If the Equalizer is the last piece of equipment before the power amps, there is a risk of
operating at less than optimal levels. While under these conditions, it is common for
power amp level controls to be set to maximum sensitivity. The problem with this
approach is that the operating levels through the equalizer will end up being quite low.
Power amplifiers set to maximum sensitivity results in approximately 0dBu for full
power. Since the system has headroom, the actual operating level could end up being
-20dBu. The XL231 has an extremely high dynamic range of 123dB, yet even under
these conditions, it may be possible to hear noise out of the speakers.
To correct this problem, set the power amplifier input level controls for much less gain.
Reducing the gain of the power amp by 12 to 20 dB will allow increasing the operating
level through the equalizer.
The goal is to have the operating level in the range of the front panel level bars. Rather
than turning the gain controls all the way up on the power amplifier, try setting gain
controls half way up as a start.
Tuning a sound system
What is the best way to use an equalizer to tune a sound system? If you ask 10 sound
engineers the best way to do this, you may get more than 10 different answers. In the
following we discuss two common methods.
There are a number of different ways to tune a room. Some use spectrum analyzers or
other computer based tools to try to measure what the room is doing, and then correct
the response with the equalizer. These are useful methods and allow one to gain insight
into the process.
One aspect that many engineers agree on is that listening is the key. Regardless of the
method used, before they are “done”, they listen to a recording they are very familiar
with and walk around the venue checking for coverage, and overall sound. The final
tweaks to the equalization are determined from this process.
One other item to keep in mind. Acoustic environments change with temperature and
humidity. When doing an evening show after a mid day sound check, one must be
prepared to make adjustments just before the show.