Gareth Magennis wrote:

Have a LEM powered sub for repair.

Speaker toast.
Amp blown/DC. (2 amps bridged for sub, one probably OK)
Relay shorted from amp to speaker.

Not sure of the chronological order of events here, but for sure the relay
did not do its job.

More of this arcing under fault conditions shenanigans I presume.


** My colleague Rod Elliot of ESP

http://sound.westhost.com/

is currently preparing an article on relays with particular reference to audio applications - one of which is dealing with large DC voltages and currents.

The site has a number of articles and construction projects written by yours truly - like this one.

http://sound.westhost.com/articles/speaker-failure.html

Lots of other tech stuff there is from me too, much of it with no formal acknowledgement.

I'll post a link to the new article when it is up.


..... Phil