Winston, the amp could still be the problem...if you are still connected to the same mono bloc..If not, then I would definitely suspect the x-over. Probably one of the x-over parts is getting hot and is therefore acting up. Once it cools, you are temporarily ok.
The age factor that you mention is the culprit.
BTW, thought you had sold the SF's...great speaker BTW!
The age factor that you mention is the culprit.
BTW, thought you had sold the SF's...great speaker BTW!