At 11:43 PM -0800 1/3/09, Robb Nichols wrote:
>Thanks to Rob and John for the windscreen suggestions. As a shell, for
>the windscreen, I'd thought about GoreTex or even Tyvek, but the ripstop
>idea seems good.
Tyvek is interesting material isn't it? Seems like its prone to flap
and crackle with movement and it appears to filter some of the high
frequencies. You can test this by sliding a piece of Tyvek between
your ear and a sound source with high frequencies.
> The siliconized nylon might be good too as the
>silicone would make water bead up. It wouldn't be UV stable, but
>nothing that I've talked about so far is. As mentioned, I don't need to
>protect the mic, but I need some kind of replaceable barrier to keep the
>windscreen from becoming saturated. Have you guys experimented with
>this in terms of audio noise from raindrops?
The hogshair diffuses the drops and lessens the impact sounds. The
role of the nylon inner-jacket is to only shed the water and let it
roll off. This skin does need to be fully water proof to prevent the
water from blowing sideways and reaching the capsules. For this
reason, I would try quality, nylon, "rip-stop" material first. It
seems to do the job with vertical surfaces an those with a low slope
like that of an umbrella. Should water form inside of the inner
jacket where a wind gust could send the droplets hurling towards the
capsules, then a more water proof cover might be in order. The
silicon coated materials could be just the thing if there is pooling
water.
Water may present a lesser challenge compared to wind protection and
shock-mounting. These sound intrusions might occur even within your
limited frequency range requirements. You might also want to look for
Rich Peet's vacuum cleaner cartridge design in the lit archive and
there's a 1993 full sphere design proposed by Harris Miller Miller
and Hanson Inc. for the DPOA that looks interesting. Rob D.
>The hogshair cover would
>help with this and would also shield this membrane from UV, but does it
>hold water? Colin, if you're following this, did you ever put together
>your system after your November posts? How is it performing? I have
>wondered if one could saturate this in a silicone oil to make it more
>water repellent.
>
>On these all-too-rare occasions of enlightenment, I stop tinkering to
>see what I can learn from others. But I'm ready to scrounge up some
>materials and try some things.
>
>Regards, Robb
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