why don't you just sell your PDX and get a nice 1ohm stable amp that puts out 2000 watts rms? With the 1.5 ohm load, your subs should see about 1500 rms or so between the two...plenty of power to get any sub rockin'! Get a nice Hifonics, they're cheap, work great (have had mine for 3.5 years now running at 1ohm day in and day out for 120,000 kms with no problems).