My girlfriend just bought me a sub that is rated at 400 rms x 4 ohms and i need to find an amp to match it but the ohms are confusing me. For example I'll see an amp that is 400 rms x 2 ohms but its only 220 rms x 4 ohms. What type of amp should i be looking for and what rms/ohms?

 

you need a 2 channel amp that does roughly 400wrms bridged @40hms