I have 4 MB Quart 6 1/2's in my 96 Saturn SL2. My inquiry is about adding a sub woofer and/or 2 other speakers to it. Can I add another speaker to my system by splitting the wires or something and have 1 go to a positive and the other to the negative? I have an external amp and some MTX Road Thunders (8 1/2's) that I want to throw in my trunk because my head unit has an HBASS feature that barely can be heard with the factory receiver driving all 4 speakers. How can I do this to get more bass? The amp I have is a Jensen 100W X 2 MOSFET. I would rather just add something that gives me straight bass than put an entire amp in if possible. The MB Quarts can handle 50-120W continuously and my receiver is 45W X 4.