"Chris Whealy" wrote in message
...
In response to comments from the reviewers and some user questions, I
have reworked my Helmholtz calculation spreadsheet - particularly the
sheet for slotted absorbers.

Thanks! This is a very easy to use implementation.

How much detail does Cox and Antonio's book go into about this calculation?
Does it take into account resonant modes which involve more than one hole or
slot? I can see I will have to buy this book but it would be nice to know
that while I am saving up.

Also, the calculation depends on knowing the flow resistance of the damping
material. Is there any handy place where one can look up the approximate
flow resistance of commonly used mineral fibre materials?

Finally a word of warning. The panel thickness can be set as low as 1 mm.
In most configurations panels only a few mm thick would be far from rigid
and, depending on the intended frequency of operation, that could have a
very major effect on the performance.

--
Tony W
My e-mail address has no hypen
- but please don't use it, reply to the group.