subs wont work
 

i need help,i gotta 03 f150,i just put in a pioneer mvh 7300 and 4 focal 5x7 access speakers run on a kenwood 8405 4 channel speaker,after hooking all up i tried to hook subs up and then the music wouldnt play unhooked subs,music played fine,hooked subs up while music playing the music got quiet and you could barely hear,unplugged subs music is fine again,any help

You have a 4 channel amp with 5 channels (4 door and 1 sub). How did you connect the sub?