The characteristic sound pressure is a characteristic value of loudspeakers. It is the sound pressure measured when applying a power of 1 W at a distance of 1 m. The characteristic sound pressure can also refer to the applied voltage, which is 2.83 V for a power of 1 W and a nominal impedance of 8 ohms.
The characteristic sound pressure is given in dB/W/m or dB/2.83 V/m. The impedance of loudspeakers is strongly frequency-dependent, therefore the power specification of 1 W or the application of a constant voltage of 2.83 V is recommended.
The characteristic sound pressure is determined in the frequency range between 125 Hz and 4 kHz and, depending on the loudspeaker, ranges from about 80 dB/W to over 100 dB/W for loudspeaker cabinets. The efficiency of the loudspeakers can be calculated from the characteristic sound pressure.