The watts-per-channel (WPC) rating always stands out in advertisements and product descriptions for amplifiers, stereos, and home theater receivers. There is a perception that more watts is better, with more watts equating to more volume. But that is not necessarily true.

When it comes to actual amplifier power, especially with surround sound receivers, you can’t just take a manufacturer’s claims about amplifier power at face value. You have to look more closely at what they’re basing their claims on.

For example, for home theater receivers with a 5.1 or 7.1 channel configuration, is the listed wattage output specification determined when the amplifier is driving one or two channels simultaneously? Or is the specification determined when all channels are being driven simultaneously?

In addition, was the measurement performed with a test tone of 1 kHz or with test tones from 20 Hz to 20 kHz?