All,
For my various SASS clones I have been making stretchy covers from
lightweight lycra fabric, which protects the mics from a light breeze
and is acoustically transparent. Over this I use a fine-knitted
beanie without any high frequency loss that I could detect. I've
also tried a loose-knitted mohair scarf, 2 layers of it, which is a
bit better at wind protection than the beanie and lets through hf.
As Rob says, fur fabric seems to cut out too much hf, I have found
this as well.
I am just now knitting a large mohair beanie (green!) for a DIY 'fur'
cover that is designed to be acoustically transparent.
If you wanted to make something even more windproof you could
experiment (as Rob has done) with a shield about the size of a large
hatbox but with fabric sides rather than cardboard. That way you
would have say 6 inches of dead air space between the fabric walls
and the mics. Maybe try one of those collapsible laundry/ garden
baskets and re-do the fabric? Endless possibilities!
Vicki
On 25/09/2010, at 3:57 PM, Rob Danielson wrote:
> At 1:42 AM +0000 9/25/10, thesilverloon wrote:
>> Rob, thanks for that info.
>> There's now no good reason not to build one.
>> Maybe except for one. Wind protection. How well can they be baffled
>> against the wind?
>> The original windsock supplied by Crown, would not appear to be that
>> effective.
>
> The stretchy material cover works pretty good until the wind gets
> into 15+ mph range. Vicki Pows adds a wooly layer to the stretchy
> material she can comment about. A single layer of burlap in a full
> surround of dead air is working pretty well for me up to about 25-30
> mph. I couldn't get fake fur to work in proximity to the SASS body
> without too much HF loss. Rob D.
>
> = = =
>
>
>> I would be mounting my AT 4022'S into this setup if I were to
>> build one.
>>
>> Paul
>> --- In
>> <naturerecordists%
>> 40yahoogroups.com>
>> Rob Danielson <> wrote:
>>>
>>> Hi Paul--
>>> Can one make a baffle using high-density foam that will provide
>>> comparable or indistinguishable performance? Its definitely doable.
>>> There are several types of high-density, _open cell_ foam out
>>> there.
>>> I tested four or five kinds and found they did pass pink noise with
>>> very slight differences. A neat aspect of foam baffle is it cleanly
>>> passes some sound energy under < 1100Hz to the off-side mic. These
>>> frequencies are critical for time arrival differences. Michael
>>> Billingsley doesn't mention this aspect of the baffle in his SASS
>>> patent as far as I can tell. Would different types of foam make
>>> audible differences? All we need to do is make some up and compare
>>> them to find out.
>>>
>>> Cutting and sanding the foam to fit snuggly into the crown housing
>>> would take some time. Vicki Powys discovered that sanding is a good
>>> way to get the final shape and dimensions.
>>>
>>> Any open cell foam that has a density of 1.5 to 1.8 pounds per
>>> cubic
>>> foot and is at least 4 inches thick should perform to Billingsley's
>>> high frequency absorption specifications. I use "charcoal gray"
>>> acoustic foam. A 10" X 10" X 4" piece should be sufficient to make
>>> a SASS baffle replacement. Measure twice, cut once. Rob D.
>>>
>>> = = = =
>>>
>>> At 11:27 PM +0000 9/24/10, thesilverloon wrote:
>>>> Does anyone know how important using the correct foam for the
>>> nose piece is?
>>>> One can buy just the foam nose piece from Crown as a spare part,
>>>> and
>>>> then build the rest.
>>>> Thats still $100 landed in Australia. But if any closed cell foam
>>>> would work,that would make the project that more do-able.
>>>>
>>>> Regards,
>>>>
>>>> Paul
>>>
>>>
>>> --
>>>
>>
>>
>
>
> --
>
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