The objective is to know the maximum sound pressure (peak) at the listening point in order to calculate the required amplifier power. With a hand-held sound level meter, set in C-weighting mode, and if it has the Z-mode, the better, but it is not common in simple sound level meters. In this way we are measuring the sound pressure given by the amplifier plus the loudspeakers, not the one received by the human ear (A-weighting). As we are looking for the peak power, the sound level meter is configured in MAX or PEAK mode, as it is called in the sound level meter model used. As a source, I would use at least two tracks that I usually listen to, one very compressed and the other with the highest possible dynamic range, both played at the usual listening level.
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