In this expose, I am going to have a closer look at one of the most fundamental of these terms: “amplifier output power”. This term is also known as “wattage”.
Let me now go ahead and explain the power specification of audio amplifiers.
“Wattage” shows how loud your amp can drive your loudspeakers. Many amplifiers will have increasing audio distortion as output power increases. Wattage is either shown as “Watts peak” which means the amplifier can produce brief bursts of this level of power or “Watts rms” which describes how much power the amp can offer for a longer amount of time. Music and voice signals inherently always change in terms of their power, i.e. the power envelope of the signal is going to vary over time. Please notice that frequently the peak power of the amplifier is going to depend upon the impedance of your loudspeakers which is commonly between 4 and 8 Ohms. An audio amplifier that has a set internal supply voltage will have a maximum output signal swing that is limited by that supply voltage. On the other hand, ideally the maker will tell which loudspeaker impedance the output power rating is being referenced to. Please note that several mini amps are not able to drive loudspeakers with extremely low speaker impedance.A Close Look At The Expression "Wattage" Of Class A Amplifiers by GM MyLink