Blown speaker question.

[Ron F]

I have a couple Philcos that have questionable speaker problems. Just what is the exact definition of a blown speaker and is it repairable?

Note: Grew up in the sixies, when the term was used all the time.

[49Stude63]

I think in my opinion a blown speaker is one that is not operational, that may be cause by a loose wire, a fried coil or a cone that looks like the cats had a fight with it.

[Doug Houston]

If a speaker (a dynamic one, especially) has had excessive power put to it, you would have a burned-out voice coil, or if not burned out, the winding will burn the cement holding it and the winding will unravel. THAT is a blown speaker!

[Chuck Schwark]

Also voice coil or cone separation or tearing from the spider. Excessive current through the voice coil could also expand or warp the voice coil (due to excessive heating) causing rubbing in the gap.

[Ron F]

Thanks for the replies; I solved the problem on my 630.
I had a rattle, and with the normal checks I couldn't pin down the problem, so I pulled the speaker cone, cleaned everywhere, put some temporary shims around the voice coil and reassembled. That cut the problem in half. Put some temporary nuts and bolts in the speaker to cabinet mounting holes and cut the problem by another quarter. Replaced the #42 tube and the problem went away. I guess when your dealing with three causes its kind of tough to trouble shoot with the quickie checks. Anyway, thanks again, Just wanted to make sure a blown speaker wasn't some mysterious, unsolvable problem like tired cone paper.

Ron F