My Corvette's set up in a way that I plan on putting a set of RS180 7" midwoofers in the doors and pair them up with a set of Seas 27 series tweeters. In the rears, directly behind my ears are spots to hold 5 1/4" speakers with a depth of a good 4-5+ inches. Because of space reasons, I do not want to deal with getting a sub. Crystal makes some small drivers specifically for such a task. Would it be a dumb idea to get 5 1/4" midbass woofers that will strictly handle bass frequencies? Or am I better of with just my 2 way setup up front and removing the rears period?