Hi John--
It does seem like the floor buffing pads could be thick, fibrous and
water-resistant enough to break-up the rain drops. I guess one could
layer them too. Let us know what you discover; I'll pick up some 18"
pads to try. Thanks, Rob D.
= = ==
At 3:18 AM +0000 12/5/08, John Hartog wrote:
>Rob,
>
>I like your description for a rain cover. I recently discovered a
>material that I think will work very well for the hog hair part -
>floor buffing pads.
>
>I noticed them in the rental section of a hardware store. The ones
>there are 1" thick non-woven plastic mesh and come in a couple
>different diameters, 13" and the larger I'm guessing around 18". They
>come in several colors that correspond to abrasiveness. Some were very
>abrasive to touch, but the tan colored one I bought is soft enough to
>be useful. They have a center hole, but the ones I found come with the
>hole piece still in place - just needs to be glued in.
>
>I got the 13" but now I'm thinking the larger one will be better for
>cutting to form a hemisphere like you describe. My initial test of
>holding it under the shower sounded very promising.
>
>I'll report back with results once this project is completed.
>
>John Hartog
>
>--- In
><naturerecordists%40yahoogroups.com>
>Rob Danielson <> wrote:
>>
>> At 12:52 PM +0000 11/7/08, colinbox wrote:
>> >From the information and suggestions you gave, Rob, I have sketched a
>> >rough design idea and recently showed it to my dad when visiting him -
>> >he worked in mechanical and civil engineering all his life. We both
>> >ran into difficulty regarding the "hogshair furnace filter" material -
>> >this term does not appear to have a direct translation into UK
>> >English! However, my dad suggested deer hide - with hair - as a
>> >possible combined waterproof and rain-noise-suppressing 'roof'. He
>> >also suggested sheep's wool as a possible material for absorbing the
>> >sound of rain drops. Both these materials are freely available to me
>> >(my brother is a deer stalker), but are these materials suitable?
>>
>> Hi Col,
>>
>> I suspect you are correct that the fine-woven, plastic material we
>> call "hog's hair" is probably called something else in the UK. Its
>> been around and used in furnace filters for many years-- most often
>> in larger furnaces where larger, custom size filters are needed. Did
>> you ask in a furnace supply company that specializes in industrial
>> and new applications? The purpose of the hog's hair is to break-up
>> the rain drops into a fine spray that are much less audible than drop
>> impacts.. You can try a layer of 1"-2" thick fiberglass. The water
>> runs through the hogs hair so whatever material you use should go on
>> top of waterproof nylon like is used in umbrellas and tents. If the
>> hemispherical cover is covered with nearly transparent materials and
>> is large (around 2 feet in diameter), the lower rim of the cover can
>> come down to the height of the mic capsules. It will take a very
>> strong wind to blow rain into the capsules in this arrangement.
>>
>> Here's the design theory of the cover: The sound-transparent cover is
>> to keep the rain and dew from falling directly on the mic wind screen
>> where it can saturate the fake fur and drip onto the mic. The
>> collection of dampness and water from blowing rain on the sides of
>> the wind protectors needs to be able to drip off without puddling
>> near the cables or mic bodies.
>>
>> Deer hide and Sheep's wool will not be transparent to sound. The both
>> will also retain too much water and become too heavy.
>>
>> >With deer-hide for wind- and water-proofing I envisage making a
>> >rectangular box with basic wood frame, hardwood "floor" (with standard
>> >3/8inch fixing for screwing shock-mounts onto), nylon covering the
>> >roof and 3 or all 4 of the vertical faces, and deer-hide (or other
>> >suitable material) attached to the outside of a larger frame which
>> >could be lifted off during dry weather... Does this sound like a
> > >viable design concept?
>>
>> I wouldn't use _any_ kind of enclosure or box around or near the
>> mics. Its likely to add resonance and interfere with mic array and
>> sound performance. What type of stereo array are you using-- the NT3?
>>
>> > The hairy deer-hide would cover the top, rear, and 2 sides to
>> >minimize noise from the house,
>> >heating system, neighbours, etc, while leaving the front unobstructed.
>>
>> So you are not able to move the mics very far away from these less
>> desirable sounds then? Increasing the distance from them is much more
>> effective because most of the sound will wrap around any object you
>> can construct-- especially low frequencies. A large tree or other
>> surface that is not highly sound-reflective can provide some
>> abatement of the mid and high frequencies.
>>
>> I wanted to experiment with 2- 4' X 8' X 1" MDF (medium density
>> fiberboard) panels, water-proofed and covered with 1/2" thick high
>> density foam in a slight "V" shape placed behind my parallel boundary
>> stereo array about 4-6' to see if this would significantly abate
>> sounds coming from the rear with my omni mics.
>>
>>
>> >
>> >Something I have discovered recently is that both my Rode NT3 and NT4
>> >mic's do not exhibit the same "sputtering" noise when connected to my
>> >external soundcard with balanced XLR connections and 48Volt phantom
>> >power... So, instead of new mic's, I need a new recorder! The Edirol
>> >R09 has served its purpose by igniting my passion for nature
>> >recording, but now I need a 'proper' recorder!
>>
>> The R09 should be a pretty good fit for your NT-4 in terms of
>> quality. I' not sure why the NT-4 would sputter if powered with 9
>> volts,.. but if it does, and the NT-4 is the mic you want to use in
>> the field, you could power it with an Art Phantom II between the R09
>> and NT-4.
>>
>> If you are after lower noise performance than that you get with your
>> NT-4 [~16 dB(A)], I'd study lower noise mics and array options first
>> before buying any recorder. Buying the recorder before looking at
>> your whole system is a common mistake. Rob D.
>>
>>
>> >Has anyone got a decent
>> >4-track field recorder (SD card or hard drive) they no longer use and
>> >want to find a good home for?
>> >
>> >Colin
>> >
>> >--- In
>>
>><naturerecordists%40yahoogroups.com><naturerecordists%40yahoogroups.com>
>
>> >Rob Danielson <type@> wrote:
>> >>
>> >> At 10:21 PM +0100 10/25/08, Colin Brown wrote:
>> >> >Thank you, nature recordists, for all the welcoming words of
>support,
>> >> >suggestions, and links. Martyn, you and your wife have my sincere
>> >sympathy.
>> >> >I'm blessed with wonderful family and friends and a great doctor
>> >here in the
>> >> >Lakes, so moving to a warmer, drier place is currently a more
>painful
>> >> >prospect!
>> >> >
>> >> >I live on the side of a hill with lush green fields stretching up
>> >from my
>> >> >garden fence to the horizon, so the idea of a microphone
>outside in an
>> >> >all-weather housing is very attractive. My garden is terraced and
>> >no more
>> >> >than 20feet from the house wall to the boundary fence. Roughly 50
>> >feet from
>> >> >the house wall are several thorn bushes, currently laden with
>> >berries which
>> >> >attract many bird species. As well as the common Blackbirds, Crows,
>> >> >Sparrows, Robin, Chaffinch, Blue tits and Great tits, a stone chat
>> >visits
>> >> >these bushes, usually in the early morning, but I have yet to
>> >record it. A
>> >> >mic outside would massively increase my chances of recording its
>> >surreal
>> >> >calls. Bats also swoop around the back of my house all night but
>> >recording
>> >> >them will have to wait until I have enough experience and
>appropriate
>> >> >equipment! All this activity comes from within an angle of
>> >approximately
>> >> >90-120 degrees, depending how close or distant the listening
>> >position is to
>> >> >the rear wall of the house. By far the most abundant source of
>> >berries and
>> >> >birdsong is a single, centrally positioned bush, again roughly 50
>> >feet from
>> >> >the rear wall of the house and 30feet from the garden fence.
> > >Unfortunately
>> >> >the bathroom, kitchen, and heating system are all located at the
>> >rear of the
>> >> >house. I can still safely use carpentry tools (on good days!) so an
>> >> >all-weather microphone housing will be my next project. If
>anyone has
>> >> >experience of building such a unit I would greatly appreciate
>advice on
>> >> >design and materials.
>> >>
>> >> Mic/array factors aside, a high priority goal of the rig design
>is to
>> >> eliminate rain and dew from striking or descending on the mic
>bodies.
>> >> A nylon umbrella will shed both or you can make a cage out of
>> >> hardware cloth that even extends all the way down the sides.
>Nylon is
>> >> fairly sound transparent. You can also layer ~1"+ thick "hogshair"
>> >> furnace filter material on top of the nylon which shatters rain
>drops
>> >> into fine spray make rainfall less obtrusive.
>> >>
>><<http://tinyurl.com/58xyyu>http://tinyurl.com/58xyyu><http://tinyurl.com/58xyyu>http://tinyurl.com/58xyyu
>>
>>A waterproof
>> >>""roof" seems to greatly
>> >> reduce moisture-related problems-- even those stemming from high
>> >> humidity.
>> >>
>> >> The NT4, like most mics, is quite prone to handling noise which is
>> >> usually addressed with some sort of shock mount. I cut out sections
>> >> of 4" thinwall PVC pipe to create suspension rings.
>> >>
>><<http://tinyurl.com/5hzsfq>http://tinyurl.com/5hzsfq><http://tinyurl.com/5hzsfq>http://tinyurl.com/5hzsfq
>>
>>People use
>> >>common rubber bands and silicone
>> >> "O" rings to suspend the mics.
>> >>
>> >> Regarding wind protection, I sew a surround out of thinly woven,
>long
>> >> pile, fake fur. The fur should be no less than 1" from the capsules
>> >> and fully enclose the capsules (if not the whole mic body).
>> >>
>><<http://tinyurl.com/6gucb2>http://tinyurl.com/6gucb2><http://tinyurl.com/6gucb2>http://tinyurl.com/6gucb2
>>
>>The wind
>> >>protection should be inside of the
>> >> umbrella or nylon-covered cage.
>> > >
>> >> Regarding Mic positioning. In addition to attending to direction,
>> >> avoid placing the mics near the ground or other large reflective
>> >> surfaces. Many recordists feel that getting the mics ar least 7' off
>> >> the ground improves clarity. Positioning the mic with the unwanted
>> >> background sound coming from the rear and with a massive object in
>> >> between can help abate the sound-- even a large tree trunk. Lots
>more
>> >> can be offered about mic positioning as you proceed.
>> >>
>> >> >There are 4 of us in my household so noise pollution
>> >> >will be a major issue. Suggestions on minimizing this
>> >noise-pollution would
>> >> >also be great
>> >>
>> >> Its true that human and machine-made sounds from your house or
>> >> neighbors tend to become annoying over time. Could you run mic cable
>> >> further away from these sound sources? I use standard, balanced,
>> >> studio-grade mic cable and encounter negligible signal loss at a run
>> >> of 700 feet. I loosely suspended the signal-carrying cables from a
>> >> taught electric fence wire stretched between trees with bungy cords
>> >> at both ends to absorb tree movement.
>>
>> >><<http://tinyurl.com/6cukav>http://tinyurl.com/6cukav><http://tinyurl.com/6cukav>http://tinyurl.com/6cukav
>> >>
>> >>
>> >> >When the weather is dry my Rode NT3 and NT4 microphones re great.
>> >However,
>> >> >this being the Lake District, most days the atmosphere is damp
>> >enough to
>> >> >cause sputtering (often more than once a minute) which far
>exceeds the
>> >> >clipping level of my Edirol R-09 recorder. That's why the Rode NTG3
>> >with its
>> >> >advertised high-humidity capability looks so appealing, 5dBA less
>> >self-noise
>> >> >would be an added bonus.
>> >> >
>> >> >Before taking either the NT3 or NT4 outside and connecting to my
>> >computer's
>> >> >soundcard (PreSonus Firebox) does anyone know whether the
>> >sputtering and
>> >> >associated clipping would harm either my soundcard or PC - or
>> >whether the
>> >> >humidity would damage mic's?
>> >>
>> >> The literature on the Firebox specifies 20dB of gain on the mic
>pres.
>> >> This spec might be misleading, but the unit might also have less
>> >> gain than is ideal, especially for ambience and night recording.
> > >> You'll just have to test it and see. The noise spec for the unit is
>> >> good. Don't be afraid to use full gain. The NT4 is not particularly
>> >> sensitive. It will work better on phantom power, not batteries.
>> >>
>> >> I suppose a first step might be to get your NT-4 up and running.
>> >> After you've done some recording, you can post some comments and
>> >> sample recordings and folks will be happy to provide some feedback.
>> >> Rob D.
>> >>
>> >>
>> >> >
>> >> >Thanks again,
>> >> >
>> >> >Col
>> >> >
>> >>
>> >>
>> > > --
>> >>
>>
>>
>> --
>>
>>
>>
>
>
--
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
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