I'd love to see this magic coating that "always improves the sound".
I've been in electronics (including industrial and consumer audio)
probably twice as long as you've been alive and never found that magic
solution. Voice coil cement, Cone dope, surround cement, yes.
Damm you are Old..)) I should have specified coating paper or fiber
cones. With plastic, I'd probably make some Paper and apply it.
Depends on the drivers. Most paper cones are coated now a days. I did
it when trying to add some mass to mids to extend the lows. I just
added white glue and changed the sound of the drivers so much, the
store I was selling to couldn't believe they were Phillips drivers.
Well, they said they never heard a system that sounded So good, and
they couldn't blow it up when they tested it, but then I Didn't go by
the book and built a front loaded, folded corner horn sub woofer that
was copied from an old University Sound rear loaded one, using a high
compliance driver, because I didn't want the efficency of the horn,
but wanted the acoustic coupling, corner loading, and reduced
distortion with a loose horn. The lows didn't go low enough for me but
opening a dead air space in the design did. Then I saw Cyclone Anti
Reversionary Headers and realized what opening the space did. Kept the
returning sound wave from canceling out the lower frequencies than the
horn design could produce. Can Feel the low notes at Low volumes. The
mids are in odd shaped boxes, open on the sides. That worked out Real
good on the woofers in the rear deck of my car. Carpet foam half round
tubes with open ends gave the lowest bass. I like low, not boom.
VF
I had contacted A.J. May at RCA who used to design their horn
speakers, when debating whether to use a horn sub, and he said, Give
it a try... As old as you are, you Must have heard of him, or know
him.))