Natural Science Forum / Physics / Acoustics / December 2003

My group has been assigned the project of redesigning the acoustics of
the university's central library. I was hoping if someone could guide
us as to how to go about our business. So far we have collected most
of the data that we would be needing. We have got hold of all the

Does anyone have or know where to find plans to build a quadratic residue or
primitive root diffusor?
Pete

Is there a FAQ for this newsgroup? If so, where can I get it? I need
to look up some basic acoustic models (i.e. difference between
spherical and hemispherical, etc..)
Any direction would be much appreciated.

I've been studying room acoustics recently and have been looking at various
models.  I have noticed that in many calculations of room impulse response
functions there are negative numbers in the output.  Does anyone here know
why there would be negative numbers in the output?  This, ...

Does anybody know where I can find
the A, B, C, D-weighting values in
one-third octave bands?
Any help or directions??

I'm reading an noise impact assessment, created using the MITHRA
model, which has a section saying
"attenuation due to  punctual sources in which energy is distributed
over a sphere of radius d, the decibels of attenuation are expressed

lost it.. :(

Dear friends:
I recently ran into a Building Code requirement (actually a Fire Marshall
requirement) that required a vapor barrier applied to the wooden studs. The
wall assembly consisted of a common wood plate with double studs, insulated,

I need to make an automatic volume control system for school happenings and
concerts...something that picks the room volume, the music volume and keeps
the music level an amount of db higher than the room one and limit the
maximum volume to a fixed level ...so that no man is