Bass Blocker

I want to get some new 6 1/2 speakers for my car and since I already have 2 subs in my trunk, I was wondering if there is any good in blocking the bass going to the 6 1/2 speakers. I've seen the things in crutchfield that block the bass. Is there any other place that sells them? Or is there another way to block bass?

bass blocker would improve sound quality, because the speakers aren't playing bass, which they aren't designed to anyways. get a 100hz high pass blocker. that should block out the bass.

radio shack sells them for like 99 cents a piece

yeah, go to radio shack and ask for a mid-frequency crossover :)