is the SPL (Sound Pressure Level) a speaker will produce given one watt of power as measured from one meter away given a typical input frequency (usually 1kHz unless otherwise noted on the speaker). Typical sensitivities for car audio speakers are around 90dB/Wm. Some subwoofers and piezo horns claim over 100dB/Wm. However, some manufacturers do not use true 1W tests, especially on low impedance subwoofers. Rather, they use a constant voltage test which produces more impressive sensitivity ratings.

The minimum input level signal required to output a specified output level.

The voltage required at the input of an electronic device in order to produce the rated electrical output. For example: in power amplifiers, the input voltage needed to produce the rated steady-state output power.

In Altec Lansing systems, the level of sine wave input signal (in Volts RMS) which, when applied to the input terminals of the amplifier of the system, will produce the targeted system output power (in Watts RMS) at the rated THD (Total Harmonic Distortion) %.

The input signal level required for a power amplifier to produce its rated output; input sensitivity is adjustable on many power amplifiers and signal processors.