Need Help and Advice
 

Hey guys, im new to this site, just joined yesterday and was looking for some advice and help. So just to let you know where my car stands, it is a 97 chevrolet cavalier and it has pioneer speakers 4x6 and 6x9 at the back, along with a pioneer deck. Past week i got some subs for free along with a bassworx box, i got 2 10" subs of Rockford Fosgates the P1's and each are rated at 150 RMS, what i wanted to know is that if i install these subs in my car and i connect the two subs together meaning one sub output to the output of next sub and then to amp would i need 150 RMS to power both or 300? And if i buy an amp rated at 400 RMS what would happen would my subs still work?

Look for an amplifier with a max output of ~300rms at the desired load.

Wiring diagrams can be found here: http://www.rockfordfosgate.com/rftech/wiringwizard.asp

So say i buy an amp that monoblock 400 RMS, for example is that enough to power both subs or is it too much, and if i connect them together so both subs are connected to one because its monoblock, do i need only 150 RMS or 300 RMS and again if i have more is that ok. My subs are rated at 4 ohms, so do i need an amp to be at 4 ohms, or what?

You'll want ~150rms per driver and with two 4ohm drivers you're looking at a 2ohm load. What you want to look for is an amplifier that will do ~300 (400-500 is just fine also) at 2ohm mono/bridged (if applicable).
If the amplifier will do more power at a lower load then that is just fine and it will give you some options for the future.

A couple great choices could include:
http://www.cardomain.com/item/ROC06P3251

http://www.cardomain.com/item/ORI47400

Cool, thanks for the help.