i have a 2001 ford ranger with an 1100 watt sub and a punch 300w x1 amp and rockford fosgate 6 x 9 's in the doors but when i crank up the bass i get distortion from my fosgate's.i was wonderin wether or not i need a bass blocker or not
What's driving the 6x9s? You're probably just getting distortion.
You're more looking for a high-pass crossover than a subsonic filter. "Bass Blockers" are designed to prevent woofers from bottoming-out at very low frequencies, which isn't likely the case.