higher resistance = lower power consumption?

I will have a guess at this, but I am no expert on such things. A bit of googling has led me to some information that would suggest that the reduced resistance is providing your higher wattage output from the same current draw. Hopefully some experts will offer an opinion.

I have a 1000w amp (APSM-1300).
If I wire it down to 1 ohm to achieve 1000w out of it, will that draw that same amount of power as if it was wired to 4 ohms at 400w? Or less?

Does having a higher resistance (lower power output) reduce the amp's power consumption from the battery/alternator?

Click to expand...

Yes that amp at 1 ohm will draw alot more from ur electrical system than at 4 ohms...with that little power i dont see a problem running at 1 ohm tho

Got an equation or something for that? I would like to have a look at it.

Got an equation or something for that? I would like to have a look at it.

Click to expand...

Im sure there is but simply wired at 4ohms ur at at say 400rms with a potential draw of 40amps from the eletrical system..and at 1 ohm or 1000rms capabilities areup to 100amps so u can see the difference that would have on a electrical system

Take the rms at said impedence and divide by 10 to get possible draw ..generic rule of thumb

Everything in this thread so far is inaccurate.

It's simple Ohm's law.

Power = Voltage x Current

So, solve for current.

Current = Power/Voltage

Current = 1000watts/12v ~83 amps.

Keep in mind this is assuming 100% efficiency, which doesn't happen in the real world. So let's assume 80% efficiency for a Class D amp.

83amps/0.8 ~ 105amps.

This is peak current draw. Music is dynamic, and you won't be drawing near that on a constant basis unless you play 0dB sine waves all the time. Also, most vehicles are at last 12.6V at battery, and around 14.4V with the vehicle running.

A great site to learn more, is Basic Car Audio Electronics

Everything in this thread so far is inaccurate.
It's simple Ohm's law.

Power = Voltage x Current

So, solve for current.

Current = Power/Voltage

Current = 1000watts/12v ~83 amps.

Keep in mind this is assuming 100% efficiency, which doesn't happen in the real world. So let's assume 80% efficiency for a Class D amp.

83amps/0.8 ~ 105amps.

This is peak current draw. Music is dynamic, and you won't be drawing near that on a constant basis unless you play 0dB sine waves all the time. Also, most vehicles are at last 12.6V at battery, and around 14.4V with the vehicle running.

A great site to learn more, is Basic Car Audio Electronics

Click to expand...

Good stuff.
Had to rub my eyes to make sure it was you posting.