Hardening drivers?

Is it possible to gradually apply thin layers of some hardening agent (some lacquer or epoxy?) on the cones of woofers to improve rigidity?
I’m mainly talking about plastic cones. First of all, do I want to make them more rigid? Are there possible high frequency break-up issues if I make plastic cones much more rigid than stock?
Obviously I don’t want to add weight so it’d have to be something thinly layered.

If there’s any sense to this, what kind of applicant do you recommend?

It’s a change from the design that was, presumably, calculated to some precision.
It will change the mass of the cone as well as rigidity.
If you know the equations it might shift things in a favourable direction though :slight_smile:
Wasn’t the BBC LS3/5 originally using hand coated woofers?
I’m thinking PVA glue applied in thin layers, but I definitely wouldn’t do it myself without some study of what the effects are likely to be.
If nothing else it should reduce cone breakup at the higher end of its range I guess, but at what cost I’ve no idea.

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Hmm, well I guess these plastic cones are already massive enough that a few layers of thin coating wouldn’t be too hefty.
Just something that gives the hardest surface with as little applicant as possible.

This idea actually came to me because I was wise to apply glycerol and later monopropylene glycol to the surrounds. Great bass.
Now, my situation is this… I have a great (fairly expensive) balanced DAC driving JBL LSR308s with XLR cables that were like 70% of the monitors’ street value. So I have pretty much a super version of these relatively low-cost monitors. Should get new monitors from HEDD but that’ll take some time…
In the meantime, I’d like to experiment further with subtly improving my JBLs. This might not be a bad idea but I certainly don’t wanna ruin them!
Has anyone done this?