Originally posted by KnuKonceptz:
Ok, I took Math/calc etc. ( Seems like years back) Now my understanding of this after playing with numbers is that R is the resistence in the wire not the amps load impedence.
R = R. If you are measuring the voltage across the wire, then that is the resistance you should be checking the voltage across. Wire should have very little resistance, almost zero. We really don't care what the resisance of the wire is when computing current draw. What we want to know is the resistance of the load, or speakers in our case. We use the nominal 2 or 4 ohms for exaplme, but really should be measured for acuricy.
Do this one 80 amps of current at 1 ohm, according to your interpretation you need 80V for it to be possible(80=80*1) I think we all know most true 800-1000 watt class AB amps will draw this amount. Now figure 14V with 80 amps R=.175 Ohms. So you going to say that in order for an amp to draw 80 amps it has to be at .175 Ohm! I think there is a more advanced law that has efficiency figured in. I haven't looked for it yet, most likely will be in my calculator as well (HP 48G)
Your calculations are not quite right.
80A into a 1 ohm load = 80V, 6400w ((80^2)/1)
I seriously doubt you are actually drawing that much current with a 1000w amp. 1000w into 1ohm (1 ohm is most current draw) is only 31.62A.
Here's where I think the confusion lies. The voltage I am using is not the DC voltage out of the batter or alternator. It is the AC voltage measured at the load (woofer) after the amplifier. No where does the 12.5V or 14.4V come into play, except that the amp can provide the voltage gain from battery to the load.
BTW, I have the same calculator (at home).
