Thanks for the reply. Do you have an opinion as to whether a bad right side amp might be causing the problem - or definitely the speaker(S)?

I have (real) Infinity speakers in my previous daily driver's doors, but still have it, '75 Alfa Alfetta GT and even though they're only 5" ones (space situation) at least they talk to my stomach, rather than to my lower legs.

You mentioned Most Bang capacitors. I read that thread and it sounds like something I also should do.

Are the two base speakers buried behind the seats fairly bullet proof?

Biba