Ah, “100W RMS.” The phrase is printed proudly on speakers, amps, and sometimes suspiciously cheap Bluetooth boxes that cost less than your lunch. It sounds authoritative, scientific even. But here’s the catch: it’s nonsense. A misnomer. Like calling decaf coffee “coffee” or a fun run “fun.”
RMS stands for Root Mean Square, which is a legitimate mathematical trick engineers use to measure the amplitude of current or voltage AC signal. The “watts” part is also real. But when you mash them together into “watts RMS,” it’s like saying “square circles.”
What is important is the average power an amplifier can put out or a load can receive.
You can have Watts, and you can have RMS voltage/current, but you can’t really have “watts RMS.” RMS voltage x RMS current gives average power. The beauty of this is that it is the same for DC or AC signals.
The proper way to say it would be something like “100W continuous average power into 8 ohms.” But try fitting that on a shiny product label. Doesn’t roll off the tongue, does it?