DY N A M I C PO W E R ME A S U R E M E N T S
About the Dynamic Power Measurements
The Audio Graph PowerCube is a test instrument used to measure the output of an amplifier in accordance with
Music
Music is dynamic; the sound waves are complex and constantly changing. In order to simulate this, the
Listening to Loudspeakers - Not Resistors
A loudspeaker is not a resistor. A resistor's value (resistance measured in ohms) is fixed. A loudspeaker's impedance is dynamic. It is constantly changing in value, dependent upon the frequency of the input signal. Therefore, measuring power with the amplifier loaded into a 4 ohm resistor is not the same as measuring power with the amplifier connected to a 4 ohm speaker. Most people do not listen to music through a resistor.
A 4 ohm speaker may experience a drop in impedance
To simulate a speaker the Audio Graph PowerCube measures output power into 20 different loads. It tests at 8 ohms, 4 ohms, 2 ohms and 1 ohm. Each of these impedances is also tested at
– 35 –