Reply to used pioneer djm 700

I recently bought a used djm 700-s from ebay and was having some trouble with it. There seems to be some audio bleeding through the headphone jack. However this does not bother me since it is very faint. However something that does bother me is the fact that all of the rca outputs in the back such as booth out, record out, and main out all seem to have a very shallow sound. They in fact sound like the bass has been taken out of them. I am unable to test the xlr jacks since i don't have that kind of cable. But has anyone ever experienced this? and if so how would you fix it. Just to clarify. I am using serato 2.5 with an sl1 box. thanks!