ok hp means a little to me.but really with these x or h pipes im trying to get the loudest most badass sound. so both of them are offroad pipes, but which one is louder?

I'm sure someone with a trained ear can hear the difference, but I don't think that most people would be able to tell the difference by sound.

This is probably true. I've read that the H-pipe is louder, but the X-pipe gives the performance edge. But, as drw0392 stated, the untrained ear probably wouldn't be able to tell the difference.

H pipe is louder, I have a H pipe my self and it sounds great with Flowmasters.