Ohms?

Be careful! Speaker impedance and efficiency are two very different things. If a speaker is 8 ohms, all that means is that the speaker's voice coil has a nominal impedance of 8 ohms (Rayhall gave an excellent explanation of impedance). The efficiency is the measure of the speaker's ability to turn electrical energy in sound waves. This is represented in db (sound wave intensity) per watt (electrical energy). The higher the rating ie. 93 db/watt, the better the speaker is in converting electrical energy into sound waves. For example a speaker rated at 93 db/watt is more efficient than one rated at 89 db/watt and their impedances can both be 8 ohms nominal.

Close, I will give you an A for your effort. Try this: Voltage is the pressure at which the water is being pushed, current is the amount of water of water and resistance is the size of the pipe. Or maybe I am wrong?? :-)