2 single 4 ohm subs cant be wired to present a 4 ohm load, you would have to run only 1 or get different subs.
this shows the ways you could hook up 2 4 ohm single voice coil subs, you can have either 2 or 8 ohms.
http://www.the12volt.com/caraudio/woofer_configurations.asp?Q=2&I=41
you would be fine running it at 2 ohms just leave loudness and bass boost off and listen for clipping or your subs bottoming out when you set your gains.
i see... so run em at 2 ohm and dont crank the gain. fair enough, but i want em dam loud. not always but i wanna be able the shake the show ya know? read on...
Why would you want a 4 ohm load? The amp you have is 2 ohm stable, so leaving the subs wired the way they are (in parallel, giving you a 2 ohm load) lets your amp put out 500W rms instead of 300w rms at 4 ohms.
for the reason that my subs cant handle the load @2ohm. cause like mentioned below, they are 150rms@4ohm and the amp is 500rms at 2 ohm. so if i cant achieve 4 ohm, how do i keep em alive?
his subs are only rated for 150 rms each but ~250rms shouldnt kill them if hes careful and knows how to set up an amp.
i dont crank em often. just to show off to my friends. (who does drive around subs cranked, like cmon) i just like the added bass. however, i've been using/setting up subs forever, but i actually dont know much about setting amps. my bass boost and gain are over 1/2 way up, but on the head unit they are turned down quite a bit.i noticed when the are cranked they sound like crap, probably due to the fact that they are "bottoming out" and i am running too many watts. i would have bought a more appropriatly sized amp ut i payed 140 cad so it was cheap. and i got the subs for 100 pair. and 20bux for wiring, and its 4 gauge, and the box cost me 30 to build to fit my ex-cab, and viala, louds music.
so i have 3 adjustments on my amp. bass boost, a filter of some kind, and gain. without gain i have to crank the bass on my head unit to get any movement out of the subs. soooo... i turned em up