sub not working

hi

my HU is stock, from there i connected the Pac-Audio adaptor where i can connect the RCA cables

i have 2 sub they are infinity 1250W SVC @ 4ohm connect to crunch PZi 250.2

also have 4 channel absolute amp connected door speakers and from 4ch amp i connected the above sub amp. this sub amp powers but subwoofer don't pump out any base it's just sitting dead.

the power is coming from battery and i used d/block to split to two(4awg in, 2 8awg out) goes to each amp only remote wire i'm sharing it on both amp

am i missing or don't wrong? can someone tell me how i can get the sub to work

TIA

each amp have ground screwed to the car

it was the ground problem

Thanks for your help