Upgrading speakers soon - a question ....

[dg5150]

As far as the front goes, is bigger always better? Will a L/R tower with larger woofers overpower a center with two smaller woofers? Would I be better off sacrificing a little bass from the towers and going with smaller woofers on the towers so that the woofers in the front are all relatively the same size? Just hypothetically, if my center uses 5 1/4's, should the towers be 6's , or could I use 8's and still have a seamless stage across the front. All the speakers would be from the same line, so they would have the same tweeter. I use my speakers 50/50 for music and movies, so I want the towers to be as big as possible for music without compromising movies.