2up crew

I phone up Honda to find out where the premier sound system amp is and they told me it's being the 6 cd changer. Because I've got a bass box wired to the rear bass speakers then to the premier sound system ( a shop wired it for me ) some how the bass currently out,the set is still working its just the bass that's not working, so I would like to know if there is a fuse for the out put for the bass on the head unit amp.

Looking to do up my Honda Accord 2.4 ivtec