Behringer CX3400 - Manual (Page 14)

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3. APPLICATION
3.1 Tools
The following tools are indispensable for a perfect system alignment. You should by all means try to obtain the
speaker specifications from the manufacturer, in order to operate the systems in their proper frequency and
level ranges. Use the manufacturer’s documentation to adjust the operating mode and crossover frequencies.
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BEHRINGER does not assume any responsibility for speaker damage caused by improper
handling of the SUPER-X PRO.
3.1.1 Measuring microphone
For making measurements you need a high-grade microphone with a frequency response that should be as
linear as possible over the entire frequency range (e.g. BEHRINGER measuring microphone ECM8000), or
at least between 90 Hz and 15 kHz. Place the microphone about 5 m in front of the speaker system to be
measured, in a height where it is on axis with the drivers of the two frequency bands you wish to measure.
When setting the levels for the individual frequency bands, delay times and crossover frequencies by means
of a measuring microphone, you should operate only one speaker stack each. Usually, the measuring
microphone needs to be repositioned between two specific measurements.
3.1.2 Generator/Analyzer
In combination with a measuring microphone and a generator producing pink noise that is fed into a channel
of your P.A. console, an analyzer gives you a graph that shows how the acoustic energy is distributed among
the various frequency bands (usually, 1/3 of an octave). The equalizer/analyzer BEHRINGER ULTRA-CURVE
PRO DSP8024 is the ideal tool for this application.
3.1.3 Your ears
When you listen to the overall sound of your system, you should walk around in the audience area and try to
detect resonance frequencies or cancellations. The sound should be optimized for the position where most of
the audience will be gathered, however, without neglecting other areas. This often means that the system
must be operated in mono. Whenever you use technical aids such as analyzers, measuring microphones,
etc., you should check the results with your ears.
3.2 Setting the input levels
Both inputs provide a gain boost/cut of up to 12 dB. Normally, the output level of the mixing console and the
input sensitivity of the power amp are the same, i.e. 0 dB in the console correspond to 0 dB in the amplifier.
In this case, the power amp is fully driven and the SUPER-X PRO should have no influence on the system
level, as all input/output controls are set to 0 dB. However, in a home recording or discotheque environment
using operating levels of -10 dBV, the power amp would still need +4 dBu, which requires some additional
gain of 12 dB. If so, the SUPER-X PRO’s INPUT control must be set to maximum.
3.3 Setting the output levels
The output levels of the single bands can be raised/lowered by as much as 6 dB. To achieve a linear
frequency response in the system, all output levels should be adjusted with the help of an analyzer. Then,
mute all outputs except for one to check the crossover frequencies and levels, play back pink noise over the
system at an appropriate volume level. Now, when you switch on the adjacent band, the level measured
around the crossover frequency should go up by 3 dB. Repeat this process for all crossover frequencies.
3. APPLICATION