I hear so many people talking about getting a 750 watt amp, over 400, 500 or something like that. Everyone is always wanting that extra hundred watts. I want to set something straight. If you are going to increase your power, to actually double your sound output, you must multiply your power by ten times. But, if your amp can handle it, you can double your sound output by doubling your speakers. Speakers move air, moving air = sound. So, when you think of spending an extra couple hundred dollars for 100 more watts, remember, your only making it about 10 percent louder, allowing for physics. Of course there are amps that sound louder, even if they are lower power than others, but remember, and efficient amp will be louder. So the numbers pretty much mean nothing, because they are subjective to the companies anyways. So just remember all this when buying an amp.