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6. Re: parabolic mics

Subject: 6. Re: parabolic mics
From: "Peter Shute" pshute2
Date: Thu Jun 16, 2011 9:49 am ((PDT))
Thanks for that. What diameter and focal length did you use?=0D
=0D
Apologies for hijacking this thread.=0D
=0D
Peter Shute=0D
=0D
=0D
--------------------------=0D
Sent using BlackBerry=0D
=0D
________________________________=0D
From: =0D
To: =0D
Sent: Thu Jun 16 22:48:03 2011=0D
Subject: Re: [Nature Recordists] parabolic mics=0D
=0D
=0D
=0D
Hello,=0D
I have used this exel=0D
http://graffiti.virgin.net/ljmayes.mal/var/parabola.htm=0D
=0D
after computation you make your elements in hard papel, you connect the ele=
ments toghether with tesa film you chose a place with sand and you put the =
paper parabola sustained by the sand. After that you make with water and cl=
ay a soup, you put the soup in the parabola for one day. With a knife and s=
and paper you makes a good mold. After that you puts the fiber glass, two t=
imes at least but you can make the parabola as thik as you like it.=0D
Good job,=0D
Best regards,=0D
Jos=E9=0D
=0D
=0D
--- In <naturerecordists%40yahoogrou=
ps.com>, Peter Shute <> wrote:=0D
>=0D
> You made your own dish? Can you share construction details? How did you d=
esign 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: <naturerecordists%40yahoogro=
ups.com>=0D
> To: <naturerecordists%40yahoogroup=
s.com>=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 foc=
us of the parabola was the line in the limit of the parabola not inside the=
 parabola, in the limit.=0D
> Best regards,=0D
> Jos=C3=A9=0D
> --- In <naturerecordists%40yahoogr=
oups.com><naturerecordists%40yahoogroups.com>, "diesel33dsl" <diesel=
mil@> 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 mak=
e comparisons (and software and measurement tools too, we could give some w=
ords here also about what tools you use).=0D
> >=0D
> > It is a pleasure to read your debates and opinions, specially now I am =
starting to take it seriously.=0D
> >=0D
> > About using parabolas, i guess my decision is to gather some coins and =
try 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 si=
nce I'd be combining two different caption ideas (thanks David B.) and prob=
ably 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 mic=
s for a stereo take of a distant element.=0D
> >=0D
> > Thanks Raimund also, your Goshawk take makes worth the try with my appr=
oach.=0D
> >=0D
> > What's clear is that small/light mikes will fit best there and omnis po=
inting to reflected sound are best choice...=0D
> > i guess the Telinga sets include good mikes on them, specially designed=
 for better performance, but has anyone of you got better results by swappi=
ng default Telinga mikes with others?=0D
> > Or, is my choice to get a Telinga set (dish, handle, mount) without mik=
es and put some specific models there?=0D
> > Which models/brands go well here?=0D
> >=0D
> > Thanks!=0D
> >=0D
> > --- In <naturerecordists%40yahoo=
groups.com><naturerecordists%40yahoogroups.com>, "Avocet" <brini@> w=
rote:=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 i=
t=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-existan=
t=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
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