after market problems please help

[sc_mustang]

I got a clarion 845mc pro audio head unit,alpine amp,2 jl audio subs,got a wiring harness,and 4 gauge amp wiring kit,OK the problem is when i cut the radio up the sub bass cuts down and when i cut the raido all the way down the subs and amp still put out some bass,IM clueless,my brother says its from the stock 460 sound system wiring but i have no clue,please help