Problems with some old Wharfedale Diamond 9.4

[bballtom]

I sold a mate who was setting up on his own my old Sony str da1200es and Wharfedale Diamond 9.4 which had been in storage for a while. Got them set up but they kept causing the amp to trip and go into “safe mode”.

After some diagnostics I deduced that it was one of the speakers causing the problem, I played the working one through both channels and it was fine.

They need to be bi wired as I’ve lost the metal bars so connected the terminals with a section of cable (did the same on the other speaker and worked fine). I then tested the sub and tweeter separately, both seemed to work fine without tripping, as far as I could tell. As soon as I connected them again with the using the small section of cable the amp tripped.

Has anyone got an idea what the problem could be? I’ve taken away the one that is playing up to have a play at home. I didn’t have enough cable unfortunately to bi wire the amp to the speaker, that could be the next test but I’m out of ideas. Always a problem when you sell to mates!

 

[Gray]

With regard to your last paragraph. If you do biwire the speaker from the amp, you will still effectively be linking those speaker terminals (just at the amp, as opposed to with shorting links at the speaker) so that won't help the diagnosis.

If I were you, I'd keep both speakers together for comparitive measurement. Start by just gently pushing the mid/bass cone on the bad one to check for free movement. If you've got a meter, compare the resistance accross each pair of unlinked and open (unwired) terminals on the good and bad speaker. A big difference would be a clue.