Re: Interior noise

[RonSwinden@aol.com]

I measured the levels in Mike Dolphins Europa and my own Ogar(Limbach pusher)
 in the cockpit they were both about the same as the figure you quote ie 93
db  the limbach is noisy  but is behind the cockpit. Mike has padding forrard
of his firewall and a high standard of construction generally. Does anyone
yet have figures with the air inlet plenum fitted?  I think sound is probably
 best limited by  attention to detail  on all fronts  ;gap sealing at all
possible sound routes ;  inlet quieting(plenum system) ; VP prop to keep revs
down etc  actual sound blanket probably the least helpful except insofar as
it renders gap sealing of the firewall and soforth easier than doing it
structurally but it may pay to use soft surrounds  for around the gaps.  I'm
not sure that adding blanket to firewall  in the unperforated would achieve
mmuch  without adding a lot of weight .  The Subaru installations  have very
elegant  sound blankets but I do not know if anyone has done comparative
tests (quantified) with the same engine and no blanket but gaps filled.
Ron S  No 33
---From Sheldon
>I am interested in what measures people have taken for cabin noise in their
>Europas. I have flown Kim Prouts plane which has no damping and have found
>it louder thatn many spam cans. He has measured it at 93dbA