Hi, Whats the difference between a symphony and symphony 2 head unit? How can i tell which one i have and are the connections at the back of the head unit the same? Also what size are the front door speakers? I have a set of 5.25 inch mids and tweeters which i want to put into the sockets. I know you can get adaptors to make them fit in the sockets, but is there a way to make the tweeters fit in the current tweeter sockets? Also whats the maximum depth i can have for tweeters and mids? Thanks.