When you’re researching the wattage of musical instrument/pro audio speaker drivers, you will often find two values for the power handling rating: RMS (root mean square), and “peak.” It’s important to know what each of these refers to in order to find the correct speaker for your amplifier.
Mean power, or root mean square (RMS) power handling, refers to how much continuous power the speaker can handle. The peak power handling value refers to the maximum power level that the speaker is capable of utilizing in short bursts. For example, a speaker with a 30W RMS rating but a peak rating of 60W means that speaker can comfortably run with 30 watts of continuous power, with occasional bursts of up to 60W.
Many speaker manufactures give you both values for a given speaker. Both values are important. You may have an amp rated at 50W continuous (or RMS), but when dimed it can put out 150-watt peaks, so you’ll want to make sure that you get a speaker or speakers that can handle those power levels.