Well for analog the output always changes, and since one mosfet is only conducting at one time for a short period of time, that one time means power goes from +ve into one pin of the mosfet and out the other (I get my source and drain pins messed up unless I stare at datasheets for 24/7) but the point is while the top mosfet is on, power flows from +ve to ground through an inductor, capacitor, and speaker and to ground. If there was no inductor, then at hoigh frequencies we can assume capacitor is almost short circuit. So let's say 1 ohm. Then speaker is 8 ohms for resistance (assuming it functions like a resistor which it probably doesn't when running). Then 1 + 8 = 9. Now current = 5 / 9 =a bit over 1/2 amp. times 5 = 2.7W
Earlier on when I was playing with mosfets and it was overheating with 7.2 volts, It turned out I was drawing 7.2 / 9 = 800mA then multiply by 7.2 = 5.76W
Still 1/2 an amp is alot of power consumption but because I'm using batteries and off a 9V battery I'm already appreciating the results from the LM386, I'm gonna give that a shot.