- old University 12" fullrange - its spider is still reasonably soft but the pleated paper surround has dried to the point where resonance is above 110Hz. I've heard of polysorbate being used - what else might work? -- got a can of automotive gasket cement but don't know if that would renew function.
Paper surround?
Maybe try zen's Mod rat glue recipe? but not sure on paper...
Another Tannoy K3809 adventure (read ? revitalization , again ) – 3 previous episodes cumulative , with finish | Zen Mod Blog
Maybe try zen's Mod rat glue recipe? but not sure on paper...Another Tannoy K3809 adventure (read ? revitalization , again ) – 3 previous episodes cumulative , with finish | Zen Mod Blog
Boob cream. (lanolin). It works on leather, perhaps it might work on your speaker. (But don't blame me if it ruins your speaker and turns the paper into mush.)
ah - am half blind besides crazy - its a cloth surround - almost brittle - lacquer thinner seems to soften the surround to some degree - at least while its wet
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It is always difficult to figure out what the old masters used. I suspect it might well be a coating of PVA based glue (water based contact glue). Reason is that this stuff stays sticky, just like the coating used on these surrounds.
-also think PVA was originally used - it may stiffen again - right now, wet with lacquer thinner and Permatex gasket sealant, its somewhat flexible - I probably should have tried water first to remove the old gunk but don't have much patience.
this is one of my favorite funky old speakers - dropped a can on its whizzer once ripping it -
this is one of my favorite funky old speakers - dropped a can on its whizzer once ripping it -
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that was probably good GM - taking chance with Permatex/lacquer thinner - wonder how long to wait to see how it did? - fs was around 119Hz IIRC - guess 70-80 might have been ~ its original resonance (?)
I have very successfully used straight glycerin (or glycerin diluted in a small amount of water or alcohol) brushed carefully onto the surround of my older speakers. Works like a charm. At first, the surround will be *very* soft. Let it dry for a day or two before using it.
thanks - will keep that in mind for EV SP12s - think I put thinned Weldbond on them a decade ago in an attempt to extend life
I was on to something with glycerin then - glad to hear confirmed by real use.
One other thing to try is cyclopentasiloxane - main ingredient of slippery hair slicker serum/gels, lubricants, food flow enhancer. It is inert and you can eat it even.
One other thing to try is cyclopentasiloxane - main ingredient of slippery hair slicker serum/gels, lubricants, food flow enhancer. It is inert and you can eat it even.
I heard from M. Poppe that Karlson used polysorbate80 on little TV speaker surrounds - those were probably new speakers with paper surround
Greg if that is the case people can pick up some light weight food grade mineral oil at the drug store in a small bottle. Handy to have as it is the purest form of oil that is available and is a great lubricant for anything. They typically have light medium and heavy available and the light would be about the same weight as an SAE20 which is about the same as 3in one oil or sewing machine oil weight just for reference. Best regards Moray James.
I'm leery of lacquer thinner, acetone or similar since it might damage the cloth and don't recall experimenting with them, though no doubt it will soften the sealing goo. The Summertime heat is enough to make the Altec's goo sag/puddle at the bottom, so either need to rotate them or use a cheap adhesive application brush to redistribute it.
Back then, all the brands, models were pretty similar to maximize interchangeability, with 12" good for 40-45 Hz output, but they were relatively high Q, so actual Fs tended to be in the 55-65 Hz range once limbered up.
GM
- hope its better than "before" as the cone was completely locked for practical purposes by the stiff surround - how long would you let it set til giving a whirl ? do you think Gasket sealant can be applied over surrounds softened by glycerin? btw - this is a UC122 University
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