ok i jsut finished installing a system in my winter vehicle, 1988 gmc safari, sub/amp/headunit ect.... so everyone sounds good, but the sub kindoff drowns out the stock(old) 6.9's, now they are only running off the HU but if i got new ones would it be louder, so onto part 2 of my question, the head unit is only running the front speakers, i dont have rear speakers, now to hook up the other 2 channels on the head unit would i jsut directly attach the speaker wire to the wires comming out of the back of headunit? and lastly should i used 6.9's again....thanks in advance