I just have a pair of boston towers right now. Nothing else. So all my bass is coming out of my mains. Its seems at higher volumes that my reciever sounds like its straining. Do you think that just getting a sub and redirecting this would solve all my problems, or should I still look into a new receiver. I think Im going to get a new receiver now anyways, and get a sub for my b-day. But do you think I dont need to???