Bass blockers

I'm about to get a Bazooka Amplified Sub Tube thingy, because currently all the bass I am getting is from my infinity 652Is, and I don't want to risk the chance of harming them, because I like to turn my bass up a lot. So, I was thinking of getting bass blockers to keep the low frequencies out of my 2 ways. I don't want to get a crossover, because that would mean an amp and I don't care to have an amp. I don't want some kick-ass system, I just want somethign that sounds pretty good and will put out some bass.

So does anyone here know anything about bass blockers? The sub I plan on getting has a frequency response up to 120Hz, so would a 120Hz bass blocker be what I need? Or would that cut out some of the bass? Also, do I need 2 per speaker? One for the neg wire and one for the pos wire? (Keep in mind, I know absolutely nothign about wiring/systems/etc.)

Anyway, thanks in advance for any help.