d) Speaker Outputs: If the UUT includes speaker outputs, connect a resistive load across each pair of output terminals equivalent to the nominal rated load impedance or lowest impedance of the rated impedance range (e.g., 6 ohm if rated 6-8 ohm). The same resistive load must be used for all amplifier tests. For self-powered or internal speakers with no accessible output terminals, output power must be measured across the speaker input leads, using the attached speaker as a resistive load.
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The following tests shall be performed on any product that contains one or more full-spectrum audio power amplifiers.
7.1. Active State Test
1) Connect the UUT to the output of the signal generator. For devices with multiple independent audio amplifiers, all amplifiers shall be connected and tested simultaneously.
2) Generate a 1 kHz sine wave input signal per Section 4.3.b. For devices that accept only digital input signals, generate an appropriate representation of a 1 kHz sine wave.
3) Monitor each channel, one at a time, with a distortion analyzer and power meter.
4) Set the volume of the UUT to 100% and adjust the amplitude of the input signal until the THD of any single channel is 1% or greater. This shall be considered the maximum undistorted power (MUP) of the channel, and this channel shall be considered the reference channel for testing.
5) Measure and record the mains input power.
6) Reduce the sine wave input signal amplitude until the output power of the reference channel is at 1/8th MUP.
7) Measure and record the mains input power.