Amplifiers with a Power Output Rating of 40-Watts x 4-Channels, 4-Ohm Final Impedance
RMS power: This rating of any amplifier is the continuous power rating that an amp is designed to output at a maximum continued volume rating. The RMS power specification is one of two numbers to go by when pairing your speakers with an amplifier, not the only 2 but a good starting point. As an example, a speaker driver with a 40-Watt, or 40W for short, RMS rating should be paired with a forty-watt RMS amplifier. We usually recommend an amp to be over powered by 10% RMS so that the power-plant does not have to work at 100% capacity to get 100-percent efficiency from your speakers. This will keep your amplifier from overheating during long periods of continuous operation.
Ohms: Is the resistance rating of an amp and is the second most important when pairing drivers with amplifiers. A power-plant that is 40W @ 4-ohm might put out 80-Watts @ 2Ω. When purchasing an amplifier, the correct pairing of a speaker’s RMS wattage and Ohm ratings with an amp’s output power rating is absolutely essential.
