Question about Ohm's

[Jake Berry]

Ok when i read about ohms, i get a little confused about how they change the power levels and such. For example, if a 2000 watt amp has 800 watt@2ohms 400watts@4 ohms and 200 watts@8 ohms does this mean a 400 watt rms subwoofer running at 8ohms would need an amp twice as powerful to hit the rms?

[HHR Ed]

you go by the amp's rated rms power at that ohm load. And each amp will be different. Most modern car amps make most of their power at 1 or 2ohms for mono amps, and 4ohms bridged for 2channel amps.

So if you have an 8ohm subwoofer, it is not optimal for high power in a car setup. And you would look for an amp that can do about 400w rms at 8ohm. The size and power of that amp at lower ohm loads would not concern you.

[HHR Ed]

But for running a single woofer in a car, Id suggest to not use an 8ohm woofer. I suggest using a Dual 2ohm voice coil or dual 4ohm voice coil woofer to run from a 1ohm or 2ohm stable mono amp.