yeah the crossover is set exactly at 80hz.
what causes a sub to bottom out? it wouldve had to have happened when i tried to hook the infinity amp up to it, cause they were fine before that

A box that is severely leaking can cause a sub to bottom out and damage the suspension, or overpowering but you haven't done that. Try turning you crossover down, somewhere between 60hz and 70hz. Where you cross it really depends on your music and listen style. I have a feeling that your box is leaking, and your subs are fine. If the suspension was damaged the sub would be drawn back into the magnet, you would notice it. Unless the suspension can be damaged without destroying it, that I'm unsure of.

If you want to fix a leaking box, take the subs out and run a bead of 100% silicone caulk or liquid nails along the seams and press it in with your fingers and allow it to cure 24 hours before putting the subs back in.

Cut the carpet where the sub gasket contacts the MDF, so it's just straight rubber -> MDF, not rubber -> carpet -> MDF.

Redrill the sub mounting holes and use new screws to get the seal tight again, overtorqued screw will cause the MDF to strip out and loosen up. A 1/8" or 3/32" drill bit and some 1-5/8" square drive decking screws in the matte black finish are awesome.

EDIT: By redrill the holes, I mean turn the sub so the new mounting holes will be "in the middle" of the original holes. Properly turning the sub will allow you to reseat the sub tight again at least 4, and probably up to 8x before the MDF is all used up.

EDIT 2: QLogic and prefabbed boxes are not sealed with caulk. That is another area they skimp on besides using staples instead of screws.

Very good advice, I usually don't think about those things as they just seem to be common sense to me, but very well said Brandon.

Thanks.

Also I would add liquid nails to the back of each hole that is not going to be used anymore, not really necessary but a nice precaution. Don't do it on the front as you need a smooth and even surface for the sub gasket to seal properly.

thanks ya'll. i guess it could be leaking from where i unscrewed the amp, but it shouldve sealed up when i mounted it back on, right?
i do hope its just a leak

Small holes like that isn't enough to damage your sub right away, but it will take away from the sound. I like to put a little silicon on all the screws I drive into the box.

So you bought some subs from somebody that didnt know they were 8 ohm?? Do they even make 8 ohm car audio subs?

Where did you buy them from and were they working fine before? Im thinking youve got some defective subs.

yeah theyve been working great for a few months now. this only started when i tried them with another amp and didnt like it because the popping sound started. so i hooked it up to the original and the popping continued