Amplifier Specifications

There are some class of amplifiers like class A, class B, Class C etc and a quick and easy way to check the true power output is to take the fuse value of the amplifier or the sum of the multiple fuses and multiply it by 6, if it is an A or B class amplifier or 10 for class D amps where the efficiency is higher. Though this will not give you an accurate result, but it will be able to indicate if your car audio amplifier is close to the specifications.