sub not working correctly

[smoof6]

i have a 2009 nissan altima, it doesn't have bose speakers, they are the stock speakers. i put it two 12" kicker cvr's with a kicker 2X750.1 amp (it's a 750 watt amp) . i have the sub getting the audio input from splicing them into the rear speakers, i did that so i didnt have to take out the stereo. i cant seem to find a good place to plug the turn on wire in to, and when i do get the subs working, they dont sound very strong almost like theyre not getting enough power, and when i turn up the music past about 10 the car speakers make a loud pop and stop working for a second, then i turn it back down and they work again, with the subs still barely working. can anyone help me please?

[AlexN09]

Did you ever get this resolved?