I used 12 gauge speaker wire from the sub enclosure to one set of pos and neg terminals on the sub, and then I only had 14 or 16 gauge on hand for the other coil so I took the smaller wire, stripped the ends, twisted the ends together, and ran it from the open set of terminals.

That shouldn't be a problem right? Both sides of the wire are transferring the current the same way, but I was just checking since I want to make sure it won't be harmful in any way.