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Re: some questions about equipments.

Subject: Re: some questions about equipments.
From: "revery" reveryus
Date: Sat Oct 12, 2013 5:41 pm ((PDT))
David,

Yes indeed, it's the front-back coincidence aspect of the two cardiod (end-=
address) microphones that Martyn describes that I am looking to minimise. I=
 can't yet see how how the taping of the two together can be done without s=
ignificant overlap of the microphones, leading to a front-back relative dis=
placement of their capsules.
Perhaps MKH40 capsules are not so close to the end of the body as is the ca=
se with the MKH8040's that I'm looking to use.

For single MS, I use SpectraFoo to compute the delay between between the M =
and S microphones ad try to adjust their positions so that is 1 or zero sam=
ples. Perhaps that is overkill, and maybe say an overlap of 0.5cm can be ac=
hieved for taping overlap (giving a coincidence error of .25cm either side =
of the S capsule) would not be too bad? A full wavelength at 10KHz is about=
 3.4cm but I would think even a quarter wavelength non-coincidence is going=
 to give some significant effects (.85cm)?

Thanks for the link to to the pdf. I have looked around at their stuff on d=
ouble MS but hadn't see this document. It will be very useful.
I had thought to use their double MS plugin, and adapt it essentially by eq=
'ing/level adjusting the inputs into it with their published specs for CCM4=
 and CCM8 sensitivity and frequency response (and adapting for the Sennhies=
ers as well). Does this sound like it would be practicable?

Regards,

Ray

On 13/10/2013, at 9:52 AM,  wrote:

>> I am also working on a double MS setup using Senheiser. The issue that's=
 been bugging me is how to mount the two cardiods above each other with the=
 capsules lining up as accurately as possible.
>
> Ray,
>
> The trick with a double M/S with two cardioids and one fig-8 is to get th=
e
> three capsules as close as possible to enable sum and difference matrixin=
g
> of the three signal. Theoretically the capsule spacing has to be less tha=
n
> the wavelength of the highest frequency to be recorded.
>
> If you look at the Schoeps paper:
>
> http://www.schoeps.de/documents/SCHOEPS_Double_MS_paper_E_2010.pdf
>
> They mount the three mics on a rigid frame and suspend that on elastic.
>
> The tricky bit is matrixing the three signals to get the multiple lobes, =
and
> they give the maths for that.
>
> David Brinicombe
>
>
>
>
> ------------------------------------
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.
>
> Yahoo! Groups Links
>
>
>







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