Topic: DIY foam windscreen for RODE NT4 - what foam to use?

[Eldo Rado]

I've read several posts here and elsewhere that a double-walled foam windscreen is just as effective, if not more so, than a "blimp" style wind screen.  In an effort to test this for myself and also maybe save major $$ I would like to construct something akin to what I've shown in the diagram below.  But I really don;t know what type of foam to use.  I am assuming that it should be "open cell" foam, for starters, but as to the density and nomenclature of the particular type of foam, I'd appreciate any knowledgeable tapers out there giving me some tips.
Many thanks for your comments and suggestions.

[MIQ]

Hi Eldo Rado

Will you be able to measure the effects on frequency response caused by the addition of your experimental windscreens?  If not, you will be shooting in the dark and may greatly change the high frequency response of the NT4. 

The folks who design and sell high quality windscreens use science and validation testing to create great performing products.  If you want to experiment without this skill and knowledge that's great, but be prepared for a trade off between saving major $$ and the performance of your homebrewed windscreen.  I'm not saying you won't be able to come up with something you like, and have fun doing so, but it is unlikely that you will be able to equal the performance of a commercially available product.

John Willett had a great post a while back about why some accessories are more expensive than you'd think.  Turns out in most cases, you get what you pay for.  To get high performance, companies need to invest in the design and development of these products and this cost needs to be recovered.

Miq

[MIQ]

Hi Eldo Rado,

Sorry for the rant above.     If you want to experiment with making screens here are a couple links to other threads that may help. 

Homemade Mic Windscreen Questions - http://taperssection.com/index.php?topic=128810.msg1701887#msg1701887

Windscreen Foam/Making Custom Windscreens - http://taperssection.com/index.php/topic,110913.0.html

DIY Blimp Windscreen - http://taperssection.com/index.php?topic=110851.msg1480061#msg1480061

This should be better than buying a random open cell foam and is still inexpensive:  http://www.bhphotovideo.com/c/product/410408-REG/WindTech_WSF_1_WSF_1_12_0_x_12_0.html

MIQ

[it-goes-to-eleven]

Will you be able to measure the effects on frequency response caused by the addition of your experimental windscreens?

Where can I get those measurements for commercial windscreens? Maybe those are published, and I've just missed it.

In addition to my very nice Shure windscreens, I have some windtech screens. The windtech foam is not very open - at all. I think they're junk.  One concern about foam is that it varies.  A manufacturer could measure and make nice claims about the performance of their test batch, but then have QC issues in what is actually being sold.  Sometimes foam should be discarded but there is pressure on a low end product to sell it anyway.   But, regardless, I'm not aware of much measurement data being shared.

As for making screens, I think the best approach is a blimp type design, with fabrics and furs rather than foams.  If you do decide to use foam, give it the blow test.  See if you can force air through it.  It's easy with the good foams, while the bad foams tend to behave more like a solid sheet of plastic.  It is possible you could slice up some sheet foam and glue it into a windscreen, or mount it on a form, but it would be a challenge.

Btw, quality windscreens hold their value surprisingly well in the used market.  But the foam does wear out, so the prices sometimes puzzle me.

[Jonmac]

The reason why foam windscreens are not very effective, is not that the wind passes through the foam, but the surface of the foam is quite
rough, and when the wind hits it, it makes a noise. The noise then passes through the foam and is picked up by the microphone.

The furry type windscreens behave differently, the hairs are quite smooth and have little friction and they also tend to move away from the
wind, producing much less surface noise.

You would be better off building a windscreen with a thin layer of foam, and a cover of fake fur.

Jon.