naturerecordists
[Top] [All Lists]

Re: Introduction and a question - windshields

Subject: Re: Introduction and a question - windshields
From: madl74
Date: Wed May 27, 2015 5:02 pm ((PDT))
Charles,

I forgot to mention windshields. These can be expensive but you can make
your own. Acoustic foam  can be expensive but all you need is a layer of
sound-transparent cloth on a frame so it doesn't flap. Two plastic kitchen=

sieves would be a starting point.

Choose a cover cloth which is thin, stretchy, and resistant to being blown=

through, like fine T shirt cloth. Test it by putting it over your head to
check that it doesn't muffle the incoming sound.

Even expensive windshields modify the frequency response but people don't
talk about that. They also change the shape of gunmic response patterns, an=
d
manufacturer don't discuss that either. All that really matters is that the=
y
make recording in a wind possible.

The bigger the radius of curvature the higher the wind speed it will
withstand without causing turbulence. End of.

An inner foam windshield will alter the response, but if the outer shape
causes turbulence and thus LF noise, anything inside won't prevent that.

Furry windshields work because they increase the effective radius of
curvature of the windshield. They also look technical. They absorb high
frequencies as will anything with a thickness similar to the HF wavelength.=


David Brinicombe







<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU