Which Amp
If you can get a PDX-1.1000 for cheap, don't let it pass!!! You can always turn your gain down. Amplifiers don't ALWAYS put out, per say, 1000 watts of power. So long as you turn your gain down a bit, your subs will run fine. Best thing is if you decide to upgrade your subs, your amp can still be used to handle higher power demands.
Yeah do it! Don't let it go or I'll find a way to catch it!! I bought a brand new MTX Thunder TA92001 amp on ebay for $400, very faithful and very loud with four 12" Thunder 9512's.


