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3. Re: parabolic mics

Subject: 3. Re: parabolic mics
From: "Peter Shute" pshute2
Date: Thu Jun 16, 2011 4:57 am ((PDT))
You made your own dish? Can you share construction details? How did you des=
ign and make the mould? How thick did you make the dish?=0D
=0D
Peter Shute=0D
=0D
=0D
--------------------------=0D
Sent using BlackBerry=0D
=0D
________________________________=0D
From: =0D
To: =0D
Sent: Thu Jun 16 21:45:30 2011=0D
Subject: Re: [Nature Recordists] parabolic mics=0D
=0D
=0D
=0D
Hello,=0D
I hope this will help=0D
http://soundcloud.com/freitojos/ms-stereo-the-first-3-5=0D
=0D
I put ms mkh 30/40 in a fiber glass 65cm parabola that I made and the focus=
 of the parabola was the line in the limit of the parabola not inside the p=
arabola, in the limit.=0D
Best regards,=0D
Jos=E9=0D
--- In <naturerecordists%40yahoogrou=
ps.com>, "diesel33dsl" <> wrote:=0D
>=0D
> Thanks all dudes!=0D
>=0D
> Most of your answers can be synthesized with a 'try it and see' basis.=0D
> Thats what I'll be doing then, once I have gear and mikes enough to make =
comparisons (and software and measurement tools too, we could give some wor=
ds here also about what tools you use).=0D
>=0D
> It is a pleasure to read your debates and opinions, specially now I am st=
arting to take it seriously.=0D
>=0D
> About using parabolas, i guess my decision is to gather some coins and tr=
y to ask one of those swedish to send me a telinga set :)=0D
>=0D
> Positioning a shotgun mic in a parabola seems quite an unexpected go sinc=
e I'd be combining two different caption ideas (thanks David B.) and probab=
ly locating the capsule in the focus is not easy due to mike size and so on=
... I guess the same happens when trying to locate there two isolated mics =
for a stereo take of a distant element.=0D
>=0D
> Thanks Raimund also, your Goshawk take makes worth the try with my approa=
ch.=0D
>=0D
> What's clear is that small/light mikes will fit best there and omnis poin=
ting to reflected sound are best choice...=0D
> i guess the Telinga sets include good mikes on them, specially designed f=
or better performance, but has anyone of you got better results by swapping=
 default Telinga mikes with others?=0D
> Or, is my choice to get a Telinga set (dish, handle, mount) without mikes=
 and put some specific models there?=0D
> Which models/brands go well here?=0D
>=0D
> Thanks!=0D
>=0D
> --- In <naturerecordists%40yahoogr=
oups.com>, "Avocet" <brini@> wrote:=0D
> >=0D
> > > Question 2:=0D
> > Is the parabola approach designed to be used with JUST omni mics?=0D
> > Are other caption patterns allowed, or is it senseless to use=0D
> > directional mics here?=0D
> >=0D
> > Dani,=0D
> >=0D
> > As a supplementary answer, try any mic with a parabola and see what it=
=0D
> > does. However, bear in mind that a double mic or a gunmic will be=0D
> > wider or longer than the high frequency focus of the parabola so the=0D
> > basic parabola theory won't apply.=0D
> >=0D
> > > Does this enhance directivity for a shotgun?=0D
> >=0D
> > You would be combining two very different directional principles and=0D
> > it is unlikely that they would reinforce each other's characteristics=
=0D
> > but try it. And it is likely that they would reinforce each other's=0D
> > disadvantages.=0D
> >=0D
> > BTW I regard the MKH 416 one of the most useful mics available and=0D
> > can't see how it can be improved on except for the MKH 816 (still=0D
> > available second hand). If you have a bottomless pocket there is the=0D
> > MKH 8070 which has an amazing spec but I can't afford two of them for=
=0D
> > stereo. :-) I think the law of diminishing returns would act here,=0D
> > money-wise.=0D
> >=0D
> > Going to basic parabola theory:=0D
> >=0D
> > a) The focus is finer at higher frequencies and virtually non-existant=
=0D
> > at low freqencies.=0D
> >=0D
> > b) An omni mic will pick up both direct sound and reflected sound and=
=0D
> > at some frequenies these will tend to cancel out, but for most wanted=
=0D
> > frequencies the reflected sound swamps the direct.=0D
> >=0D
> > c) A cardioid theoretically avoids cancellation effect type b) but=0D
> > other diffraction effects still apply. A cardioid is always more=0D
> > susceptible to wind and handling noise. Take your pick on=0D
> > disadvantages.=0D
> >=0D
> > d) Stereo with a parabola is only possible using two points just=0D
> > off-focus on either side. The theory behind this is complex so trial=0D
> > and error is the best method of finding out what works.=0D
> >=0D
> > David=0D
> >=0D
> > David Brinicombe=0D
> > North Devon, UK=0D
> > Cogito cogito ergo cogito sum - Ambrose Bierce=0D
> >=0D
>=0D
=0D
=0D
=0D









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