Battery power ????

[phebus]

Does your amp draw more from your battery if you run it 4 ohm or 2 ohm.
I know it puts out more power at the lower ohm load, at lower resistance, but is that a bigger draw on your battery then less power, but greater resistance?

[speedaddict]

There's no magic here.. 1000w, regardless if it's a 500watt amp running at 2 channels into 4 ohms, it's drawing 1000 watts, and the power supply will pass at least that much to your battery.. if you run a competition amp that is rated at 125 x2 at 4 ohms into two 4 ohm speakers, you'll burn 250 watts, if you run two 2 ohm speakers, you'll burn 500 watts, if you bridge it into a single 2 ohm speaker you'll burn 1000 watts.. this would have the same relative draw on your battery as the afore mentioned 1000w amp driving 2 4 ohm speakers at 500w. If you want to be more efficent, and get the most from your battery and alternator, look into a D class or E class amp for your sub. They are around 25% more efficent then the standard AB class amps... result: your 1000 watts to the speaker pulls 1100 watts from your battery, rather than 1300 watts.
Bryan

[phebus]

So, lets use a 800w amp rated at 100x4 @4ohms, and at 200x4 @2 ohms (since that's what I've got) powering 8 speakers @ 2 ohms is drawing 800 watts? And that is at full power correct? Or, should I say full volume? If it's turned down, it draws less correct, the 800w is it's potential?
What I'm trying to understand, is it drawing twice as much powering 8 4ohm speakers at 2 ohms vs running 4 4 ohm speakers at 4 ohms.

[ROZ]

Amp draw is limited to your finger and fusing.....You're right to think that more current is demanded....

[phebus]

Amp draw is limited to your finger and fusing.....You're right to think that more current is demanded....
In my case yor wrong Roz. Current draw is limited by my wife yelling at me to turn it down. :D

[ROZ]

So, lets use a 800w amp rated at 100x4 @4ohms, and at 200x4 @2 ohms (since that's what I've got) powering 8 speakers @ 2 ohms is drawing 800 watts? And that is at full power correct? Or, should I say full volume?
That is at optimum performance....
If it's turned down, it draws less correct, the 800w is it's potential?
Yes... And because frequency changes, volume demand changes, and voltage changes(as battery goes down, long wire runs, demand, etc.), you can't pinpoint exact current draw from the battery(s)...
What I'm trying to understand, is it drawing twice as much powering 8 4ohm speakers at 2 ohms vs running 4 4 ohm speakers at 4 ohms.
Math says yes...