I jumped to Jorg's findings in the article a few
years ago and stopped there. Maybe foam doesn't
get the respect it deserves from the winds here
in the midwest.
I've made a few very simple zeps using fake fur
that the Rycotes and Sennheisers I've tried
can't match in terms of rejection and I'm never
bothered by tonal impacts, if there are any. My
best performing zeps seem to be good matches for
particular mics-- with more interchangeability
with omnis. I do have several mics I'd like to
outfit better and could do some tests if there's
some agreement on key test variables.
Putting how to create a realistic, "control" wind
and materials aside, is there an incoming-wind
angle) that is usually most challenging for mics
or is there variation from mic to mic here?
(Like, head on?) Putting tent size baskets
aside, would it be worth it to test fairly small
differences in basket size or just start off with
"adequate size" and try much larger and smaller
scales? Do we have any idea about the effects of
head positioning for different polar patterns
inside of the basket or is "roughly in the
middle of the sphere shaped basket" good enough?
Rob D.
=3D =3D =3D
At 2:27 AM +0100 2/24/05, Klas Strandberg wrote:
>It's nice to have quality text to read, isn't it....
>
>One thing which J=F6rg (I have met him and discussed those things) didn't
>mention is that a windfoam works better, the bigger it is; bigger - not
>thicker.
>The best windprotection is a big tent with no acoustics.
>
>Klas.
>
>At 00:52 2005-02-24, you wrote:
>
>>Those who know me know that I tend to take an academic
>>viewpoint on these things. I did a quick check of
>>what has been published in the Journal of the Audio
>>Engineering Society, and found a couple of helpful
>>papers:
>>
>>"Microphones and Wind", Wuttke, Jorg; JAES, vol. 40,
>>No. 10, 1992 October
>>
>>"Windnoise Meausrement using Real Wind"; Woolf, C,
>>Prudden, O., AES preprint 5269, 109th Convention of
>>the AES
>>
>>Jorg Wuttke is chief engineer of Schoeps. I'll try to
>>give a brief synopsis of his paper here:
>>
>>Pressure microphones and pressure gradient microphones
>>have different sensitivity to wind noise.
>>Measurements presented at a wind speed of 18 kph for
>>the Schoeps MK-2 (omni) and MK-41 (cardioid) show
>>about 20 dB greater noise at low frequencies for the
>>cardioid. The difference diminishes to about 10 dB at
>>500 Hz. There is still significant wind noise at 1
>>kHz.
>>
>>Both basket-type and foam windscreens can be
>>effective. Foam windscreens tend to merely attenuate
>>the highest frequencies (about 2 dB in the top octave
>>for the one evaluated in this paper) whereas the
>>basket type has less overall attenuation but
>>introduces narrow-band peaks and dips amounting to
>>about 10 dB peak-peak.
>>
>>The basket type windscreen is more effective at low
>>frequencies, but less effective at mid and high
>>frequencies than the foam windscreen.
>>Quote "
>>Conclusions
>>
>>Foam windscreens should be used wherever the
>>protection they offer is sufficient, for their
>>negative effect on the sound is relatively small and
>>easily correctible. On pressure transducers they are
>>almost always the best choice.
>>
>>Basket-style windscreens must be used on directional
>>microphones if foam types are inadequate to reduce the
>>levels of wind interference. They do detract from the
>>sound and directivity of a pressure-gradient
>>transducer to the degree that they are small and
>>efficient. A good compromise between the two types is
>>a hollow foam windscreen. In all cases care must be
>>taken to avoid overloading the microphone channel's
>>input electronics due to the excessive very low and
>>even infrasonic frequencies produced by the action of
>>wind on the microphone diaphragm. Attenuating the
>>system's low-end response at the earliest opportunity
>>is always a good idea to ensure a clean transmission.
>>*******************************************
>>end quote
>>
>>Now, if you don't happen to agree with this, don't
> >shoot me. I'm only the messenger.
>>
>>eric
> >
>>
> >
--
Rob Danielson
Film Department
University of Wisconsin-Milwaukee
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