Help installing a subwoofer?

I want to get my sweetie the following subs for our Xterra:





Subwoofer Size: 12"


Voice Coil(s): Single (1 voice coil)


Impedance (per voice coil): 4 ohms


Peak Power Handling: 1200 watts


RMS Power Handling: 400 watts


Woofer Surround: Rubber


Woofer Composition: Stainless Steel-coated Polypropylene


Sealed Box Volume: 0.8 - 1.75 cubic feet


Ported Box Volume: 1.0 - 2.0 cubic feet


Sensitivity: 90 dB


Frequency Response: 25 - 800 Hz


Xmax (millimeters): 11.3 mm


Top Mount Depth: 6-11/16"


Cutout Diameter: 11"


Warranty: 1-year Sonic Electronix





There 2 of them. Is this good? Also, do I need anything else to install them?|||sounds good you'll need an amp to power them up. i would suggest you get at least an amp that has 800 rms @ 2 ohms. i would go with the 750.1 kicker amp or the 1000.1 kicker amp if you go with the 1000.1 make sure you don't put the adjustment too high cause it'll damage the subs. and don't forget the amp kit (amp wires) go with a 4 gauge amp kit.|||These are great subs but if you want awesome sound and what you need to have anyway is to get an amplifier. Here a link to one that will work.


http://www.sonicelectronix.com/item_9356鈥?/a>





Also, to keep your cars power source alive I suggest you get a two battery setup and an alternator that can put out 265+ amps