If this is the org I am thinking. This is how they determine power output. Great rog to run. Very equal and relies on skills to get the numbers.
A Volt meter will be placed on the speaker leads coming out of the amplifier going to the sub(s). Then a Ammeter/Current meter is “clamped” around the positive(+) speaker lead at the same point as the other meter. The “peak hold” feature is selected on both meters. A competitor will have 30 seconds to achieve their highest SPL. During the run, the meters will keep track of the peak voltage, amperage/current coming out of the amplifier going to the subwoofer.
After the run, the judge will examine both meters and multiply the measurements together to determine max wattage. Example: (50ACV x 10ACA = 500 watts).