For a short history. I purchased a Bergantino NV610 from a place in detroit michigan. When I got it, it had one of the speakers replaced with a different looking speaker, and it sounded blown at that. Apparantly the original speaker had blown, and they put an ampeg 10" speaker in there while the other one was getting re-coned. After speaking with the shop and Jim Bergantino, I finally got a new speaker sent to me direct from Jim himself. I have since installed it, and it sounds damn fine, but I can see this speaker moving NOTICEABLY more than the other speakers. I would say the excursion is at least twice the other speakers. Now it's possibly true that this cab blew both the original speaker and the replacement ampeg speaker in this one location. And frankly i'm scared it's going to happen again. what could be causing this, and what can I do to fix it?