Speaker Glow

[Sigilion]

I had an odd problem the other day, and haven't been able to find anything through forum search. We were setting up our portable sound system with a rented snake, and we used the snake's two monitor returns to connect an electric keyboard to the mixer. I couldn't get the keyboard sound to come out of the speakers, so I turned off the other channels of the mixer and turned up the main output to see if I could get any sound at all, at which point the speakers began to screech quietly and a yellow glow appeared from inside them. It turns out that one of snake wires was TRS and the other was TS, and we has used a TS patch cord to connect to the TRS snake wire and a TRS patch cord to connect to the TS snake wire, and after switching these everything worked fine.
Does anyone know what was happening?

 

[rwhealey]

Some speakers have an automotive light bulb used as a protection device - I bet you you caused feedback, overloaded the speaker, then protection circuit kicked in and dropped the level - which is why the screeching was quiet.

 

[Blacksheep0317]

Im agreeing with rwhealey. Esp being from toronto I think it is a safe assumption that your most likely running with some Yorkville boxes? We have a ton of them around here as well since Yorkville's American office is about 4 miles from where I am sitting. They are famous for having little light bulbs as a "fuse" so to speak. Great system actually..

 

[Sigilion]

Yes, they were Yorkville speakers.

Thanks for your help.