Hi Alex, thanks for the response.
I'm certain that I have swapped speaker cables at some point over the last year, but to be honest I can't be certain so will test that when I am back in town.
As for the offer for a phone call - a conversation would be great, but I can't seem to access your profile to send a PM ... And "My Messages" does not show a "New Message" option.
Apparently this newbie has very few privileges. WTF?