Audio Systems: Matching an amp with subs, watts rms, deep cycle battery


Question
Hey man i wanted to know if you could recommend an amp for me. Right now i have 2 15inch legacy subs at 4000 total watts each, 2000 rms each and i think 4 ohms each too. I want em to really BANG, so what would you recommend?

Answer
Look for an amp that's 4000 watts RMS @ 2 ohm and wire the subs parallel.

Side note:

If your total system power is 1500 watts RMS or more,  you will need to:

1. Upgrade the alternator to a high output alternator
2. Upgrade to a heavy duty deep cycle battery
3. Upgrade the "Big 3" - that is to replace (or add to) the power wire between the battery and alternator, the ground from the battery to the chassis and the ground strap from the engine/tranny to the chassis with at least 2 AWG wire.

Failure to do this will result in the early death of the alternator  as it will eventually fail.

Here is a guide that will calculate what size alternator and power wires you need  http://www.datafilehost.com/download.php?file=6d26c621

You will need Microsoft Excel. If you don't have Excel, use this link http://www.box.net/shared/nkkw1dhk4g

A second battery is never a good idea as it's an added strain on the alternator to charge two batteries AND supply power for the car. The ONLY time a second battery is useful is if the audio system is to be used with the car off.

A capacitor is only good so far as the audio system isn't trying to pull too much from the electrical system. A cap doesn't provide more power, it's designed to 'stiffen' the voltage to the amp, nothing else. If the current isn't there, a cap won't help.
The alternator must have at least 20% more amperage power than the entire vehicle and sound system combined for a cap to be of benefit which is ironically the same requirements for an amp to be efficient.