Can the cone on my subwoofer be repaired?

I think I already know the answer but might as well check anyway. I hooked up my 2 10's that were given to me and the one was rattling a lot. Upon further inspection I noticed what looks like (doesn't go all the way through) a small slit about 2" long on the speaker. It's an Audiopipe 1200 watt sub and it's only about an $85 sub but still,if I could repair it (for the time being as I plan to upgrade my system eventually) I would be a little happier. One 10" sub just isn't cutting it. It's got a nice sound but I'm wanting a little more 'thump.' Thanks in advance for any info.