I bought a second sub that was the exact same as the one i already had. I found it on craigslist in florida. Not sureit was important that it was the same but at the time i was on a mission lol. I ended up replacing the woofer in the sub with a driver from parts express and they sound identical to my ears, so as i say im not so sure you would really need a matching sub.
See if yo can borrow a second sub from a freind or buyone and return it if you dont like.

DOG is GOD spelled backwards.
What others think of me is none of my business.
M80 V3 MY GLOSS Cherry