Here's a little trick I've tried twice that I thought I'd share. Spraying WD40 all over a paper speaker to "fix" it.
The first time I did this was with an 8" 1930's speaker I picked up somewhere that was terribly rusted and the vioce coil seemed to be rubbing. It sounded blown and had that grindy sound if you pressed the voice coil in a bit.
It was made so that you could easily see the voice coil and the magnet, and the magnet was rusty. As it didn't have a cover of any kind over the voice coil, just a little slotted bakelite/plastic thingy, I doused the voice coil liberally with WD40 and played loud music through it until the rust wore off the magnet so the voice coil could move easily. And yes it actually worked! After a few days of spraying it and messing around with it the speaker eventually healed itself and sounded really rather good, until the bakelite/plastic thingy crumbled away from old age. But while it worked it sounded very good.
Yesterday I obtained another pair of old 12" Hammond organ speakers that were not in great shape with signs of rust and on one of them part of the cone had come unglued there at the frame by the magnet. Looked to have been that way for ages. Anyway, I glued it back together with Serious Glue (wonderful stuff) but there was still terrible grating voice coil rub, presumably from moisture and crap getting in over the years while it was unglued.
So I decided what the Hell, it's already toast so why not experiment? So I cut a hole in the paper dome over the voice coil and sprayed loads of WD40 into it and hooked the speaker up to a 30w amp with a bass guitar and started whacking the strings to basically cause the most square wave jiggery pokery I could, sending the ancient paper cone in and out to it's extremes.
After about an hour of such activity the speaker hadn't blown but it HAD become significantly less grumbly at the voice coil.
I sprayed the whole paper cone with a liberal dose of WD40 and left it over night. Today I've worked the voice coil with WD40 some more and blatted it with the bass amp and now when played at sensible volume with a guitar it actually sounds like a speaker again. The voice coil rub is gone.
I do notice a bit of volume decrease, probably due to the cone still being saturated with WD40, but the overall tone is excellent. Perhaps if I can find a way to dry out the speaker cone now it'll get even better!
The first time I did this was with an 8" 1930's speaker I picked up somewhere that was terribly rusted and the vioce coil seemed to be rubbing. It sounded blown and had that grindy sound if you pressed the voice coil in a bit.
It was made so that you could easily see the voice coil and the magnet, and the magnet was rusty. As it didn't have a cover of any kind over the voice coil, just a little slotted bakelite/plastic thingy, I doused the voice coil liberally with WD40 and played loud music through it until the rust wore off the magnet so the voice coil could move easily. And yes it actually worked! After a few days of spraying it and messing around with it the speaker eventually healed itself and sounded really rather good, until the bakelite/plastic thingy crumbled away from old age. But while it worked it sounded very good.
Yesterday I obtained another pair of old 12" Hammond organ speakers that were not in great shape with signs of rust and on one of them part of the cone had come unglued there at the frame by the magnet. Looked to have been that way for ages. Anyway, I glued it back together with Serious Glue (wonderful stuff) but there was still terrible grating voice coil rub, presumably from moisture and crap getting in over the years while it was unglued.
So I decided what the Hell, it's already toast so why not experiment? So I cut a hole in the paper dome over the voice coil and sprayed loads of WD40 into it and hooked the speaker up to a 30w amp with a bass guitar and started whacking the strings to basically cause the most square wave jiggery pokery I could, sending the ancient paper cone in and out to it's extremes.
After about an hour of such activity the speaker hadn't blown but it HAD become significantly less grumbly at the voice coil.
I sprayed the whole paper cone with a liberal dose of WD40 and left it over night. Today I've worked the voice coil with WD40 some more and blatted it with the bass amp and now when played at sensible volume with a guitar it actually sounds like a speaker again. The voice coil rub is gone.
I do notice a bit of volume decrease, probably due to the cone still being saturated with WD40, but the overall tone is excellent. Perhaps if I can find a way to dry out the speaker cone now it'll get even better!
Being oil based it will be a long time before the cones dry out . WD recently introduced a new range of
" specialist " sprays , i 've been using the electrical contact cleaner on volume pots faders etc for some time now and it works really well , drys fast and leaves no residue . Don't know how effective it would be for your " experiments " though .
" specialist " sprays , i 've been using the electrical contact cleaner on volume pots faders etc for some time now and it works really well , drys fast and leaves no residue . Don't know how effective it would be for your " experiments " though .
Interestingly enough I left the speaker in a warm place all day and when I came back to it the paper cone was definitely a bit drier. I've just given the speaker another blatt hooked up to a 10w guitar amp and it sounds a bit louder now and the tone quality is still quite good. I think it's going to work. I'll bung it into a proper speaker box sometime soon and really give it a bash to see how it holds up.
Not sure what to do about the 5p sized hole I cut in the voice coil dome. It doesn't seem to make any difference to the speaker and I do know many older speaker designs had the magnet and coil exposed to the open air so I might just leave it that way and see what happens.
The previous speaker I sprayed with WD40 took some months to dry out before it seemed almost normal again so yes the oil based WD40 is probably the wrong thing to use really, and it probably plays hell with old glue but the results have been interesting. That one was in daily use at low power in an old 1940's wooden cabinet that I'd converted into a powered speaker for my computer. Maybe the old dry wood in the cabinet helped the speaker cone dry out.
In all it's just been an interesting experiment to see if I could bring a crappy old rusty speaker back to life and it seems to have worked, at least temporarily. I wouldn't be losing anything if it didn't live long because I've got a few extra speakers like this around as spares.
Not sure what to do about the 5p sized hole I cut in the voice coil dome. It doesn't seem to make any difference to the speaker and I do know many older speaker designs had the magnet and coil exposed to the open air so I might just leave it that way and see what happens.
The previous speaker I sprayed with WD40 took some months to dry out before it seemed almost normal again so yes the oil based WD40 is probably the wrong thing to use really, and it probably plays hell with old glue but the results have been interesting. That one was in daily use at low power in an old 1940's wooden cabinet that I'd converted into a powered speaker for my computer. Maybe the old dry wood in the cabinet helped the speaker cone dry out.
In all it's just been an interesting experiment to see if I could bring a crappy old rusty speaker back to life and it seems to have worked, at least temporarily. I wouldn't be losing anything if it didn't live long because I've got a few extra speakers like this around as spares.
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