its a sony, and it has a sub setting and sub-out plugs that what i have the sub plugged into. i looked everywhere in every setting i could find to see if the head unit was doing somthing, but there are no settings for just the front or just the back speakers anywhere i could find,except the fade, which i changed all the way front and nothing. i even changed it to some differant preset audio settings (pop, jazz, rap, club, xplode..e.ct) and all of them gave the same problem.

is there somthing that i can measure (i have a multimeter, not sure if that helps) on the speaker leads comming out of the stereo that will tell me if its not putting out the bass? or just hook a speaker directly to it and see what happens? it also has rca plugs for front and back, if i get the prob from the regular wires comming out of the back ill try the RCAs too.

thanx for helpin out everyone.