It refers to the electrical power coming into the speaker (not the acoustic power). It is the amount of power (in watts) that can be made to the speaker before distorting too much or it can be damaged. Within the potency difference between rated power and power handling.
Maximum power, continuous duty, the speaker can withstand before deteriorating. If the speaker is operated above the rated power can irreparably damage the speaker because it cannot dissipate heat produced by electric current flowing through the coil and it can melt the insulation covering the copper wire that form, causing short circuits or cutting back by melting the copper wire.
Maximum Peak Power or allowable power
Impulsive peak power (peak signal), which may support the speaker time to time before deteriorating. Corresponds to the maximum instantaneous power is applied during a very short time. This value is closely related to another limitation of the speakers that is the maximum travel of the coil without destroying the diaphragm (called unknown speaker). This power is greater than the maximum average power. These first two are perhaps the most important but there are others whose measure is important for understanding the behavior of speakers in the short, medium and long term.
P.M.P.O. (Acronym for Peak Music Power Output) is a specification of common power consuming equipment such as cassette players or mini components representing the peak value that is capable of supporting a speaker during an extremely short time (usually 10ms), and is usually measured to that the speaker is burned, giving values greater than the maximum peak power. It is important to note that this specification is the speaker and not the amplifier that feeds, which can give false hopes to buy a team. In other words, the PMPO power is not a “real” value, but rather commercial sound power. To more accurately recommend using the rms or RMS (Root Mean Square) which represents the real power that the amplifier is capable of delivering.