QSC Audio CX Series User Manual

Page 25

USING COMPONENTS WITH DIFFERENT VOLTAGES

Sometimes it may be practical to use a transformer or loudspeaker/transformer combination with a different

voltage system from what it was originally intended. For example, a 70-volt transformer could be used in a 25-

volt system, although you would have to derate the power taps similarly. Never use a transformer with a higher

voltage than what it is designed for, though; i.e., you couldn’t use that same transformer on a 100- or 140-volt

line.

To properly derate the transformer tap power levels, locate the column with the voltage the transformer is rated

for in the table below, then locate the row with the system voltage you want to use it in. The table will indicate

the dB reduction to use with the derating chart below it.

EXAMPLE

You have a 70-volt transformer with taps labeled 0.6, 1.2, 2.5, and 5 watts. What power points will

those taps provide on a 50-volt line?

The table shows that 50 volts is 3 dB less than 70 volts. The chart confirms that the taps will provide

0.3, 0.6, 1.25, and 2.5 watts, respectively.