Diff bewteen A/B and class D amps.

[ahole-ic]

efficiency is the energy lost to heat simply put, theres a little more to it but...

It's not lost TO heat. It's lost in the form of heat. To clarify, heat does not cause inefficiency, it is the result of it. To explain efficiency, lets say your amp is drawing 100 amps and the system voltage is 12v. p=i x e so 12 x 100 = 1200w right? Wrong. The amp is changing this dc power input to ac output at varying frequencies with the input signal to make music. It does this at a loss because humans cannot make anything that is 100% efficient. The rate at which we get usable energy on the output side vs what we put in on the input side is efficiency. If you clamped your power and got 900 watts, you'd be 75% efficient. This means you lose 1/4 of the power you put in.

 

[ahole-ic]

The subwoofer motor assembly is the biggest waster of power converting it to heat! //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

I don't want to quibble on a technicality, but there are noobs trying to learn so... maybe it needs clarification. The "motor" as referred to by builders and people who know, is the fixed magnet of the woofer. To be a motor, of course it takes the voice coil, which is what gunz was referring to. Specifically, the voice coil is the only thing that power goes into thus the only thing that can waste it. It transfers energy by becoming an electromagnet and reacting with the fixed magnet (motor) but still, the voice coil is the only thing that can waste energy and create heat.