Alto CYCLONE User Manual page 37

The final links in audio systems are graphical equalisers, loudspeaker processors and finally amplifiers and speakers.
Graphical equalisers have the same problems as the Cyclone's EQ. If excessive boost is applied to the signal, the
graphic equaliser's output (and subsequent electronics too!) may be overloaded. If, Cyclone output is higher than
the maximum input level of the graphic, the input of the graphic equalizer may be overloaded.
Loudspeaker processors have similar problems. If the input level to the processor is too high, the input may be
overloaded and introduce distortion into the outputs (and to the speakers). In addition to this, any boost on the
processors outputs (e.g. 3dB more bass) will cause that output to overload earlier (in this case 3dB before the other
outputs). Finally, amplifiers can introduce the most interesting results. An amplifier has a sensitivity. That is, an
input signal level that causes the amplifier to produce it's maximum
output level. For most of the amplifiers it's 0dBu (0.775 volts RMS), others use 0dBV (1 volt RMS) others use dif-
ferent levels. Beyond this sensitivity, the amplifiers output will not be able to produce any more power and 'CLIP'
(usually indicated by some serious looking red lights). Sending +22dBu level from the Cyclone will clip the output
of most amplifiers causing damage to your loudspeaker system.
There are a number of solutions to this problem:
Reduce the amplifiers input attenuators to a level where the amplifier and console clip at the same point.
e.g. The input sensitivity is 0dBu, setting the input attenuator on the amplifier to +22dBu would mean that the
console would clip at the same time as the amplifier. So operating the console sensibly the amplifier should
never be clipped. The console LED Meters will also accurately show the available headroom left in the entire
system.
+22dBu may not be a sensible level to set as many operators choose not to run the output of the console so
high. That is personal choice.
Run the output of the console at a level below 0dBu
This solution means that you won't get full benefit of the console, and may suffer a reduced signal to noise ratio
especially when running over long signal cables. But the amplifiers should be saved from clipping.
As with many things in the audio world, use your ears. If something sounds distorted check:
Input Gain too high?
EQ Too Much Boost?
EQ Too Much Cut coupled with a High Input Gain?
Too High a level into Inserted Processor?
Clipping Loudspeaker controller or Amplifiers?
Final links
(lower input gain and check)
(disable EQ and check)
(disable EQ and check)
(disable insert and check)
(Check both CLIP LEDs)
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