omichalis
Date: Fri Jul 22, 2011 6:53 pm ((PDT))
I totally agree with everything :)
you can' t have a set of mikes that do everything.. you need the right tool=
for each occasion
On 23 Jul 2011, at 04:41, John Lundsten wrote:
> Marinos Koutsomichalis wrote
>
> @ John
>
> > The maths
> > W =3D Front + Back cardioid
> > X and Y, will depend on how you orientate the mic. But will be:--
> > Front - Back cardioid
> > The Fig8 mic
>
> "this is exactly my point - I do not think you will get the same results =
as
> you would with 4 cardiods even if you do the right math - it may be right=
in
> theory, but the theory makes some assumptions"
>
> Sorry if you got the impression I was saying a Schoeps Double MS rig was=
> going to sound the same as a Soundfield Mic.
> Very far from it, which was in a way my reason to say (well I thought I'd=
> said) . If you like the qualities of a Double MS rig but want a B-format=
> signal, because of it's post production potential, then it is quite easy =
to
> convert DSM to B-format.
>
> "take for example the XY vs MS paradigm, in theory you can just convert
> between the two,"
>
> Well you can, so long as one is talking for example of taking a digital
> recording in XY form & Sum & differencing the 2 tracks into MS. It will b=
e
> perfect. You could convert back to XY & the result will be indential, it=
> would pass a "null" test.
> You could if you wish convert back & forth many times.
>
> "However in actual practice if you record in the first place with a MS mi=
c
> and you compare it with a XY pair converted to MS, you will not get the s=
ame
> results. "
>
> Absolutely, no doubt about that at all, IMO.
> MS, Double MS, Blumline pair & sound-field type mic arrays are all
> "Coincident" mic techniques. The ideal is all mics are in the same physic=
al
> place.
> This is impossible, so at higher frequencies the minimum spacing possible=
> starts to introduce significant errors.
>
> How audibly significant these errors are will be influenced by the mic
> technique you used, the source material & your priorities & tastes.
>
> A technique like XY depends quite heavily on the idea the off axis respon=
se
> of the mic, tends to perfection.
> Eg a "perfect" cardioid would be 6db down in level at 90deg off axis, and=
> infinity dB down at 180deg. All frequencies will attenuate by the same
> amount.
> Again such a mic does not exist, even mics that have well regarded off ax=
is
> response, still sound way better on axis.
>
> What this means to me, from a practical point of view, is where I want a=
> stereo recording with maximum sound quality & image stability for sounds=
> coming from the median plain (centre), MS makes a lot of sense.
> If say I'm recording orchestral music where the client wants the 1st & 2n=
d
> strings (placed L&R) to sound great but don't care so much about the perc=
&
> wind inst, dead centre. Well then XY has loads to offer.
>
> But back to the "maths" point, every mic array will have it's qualities. =
If
> you want to convert from 1 supposedly coincident technique to another you=
> can preserve those qualities whilst converting to another format, with th=
e
> right fomula.
> JL
>
>
--
Marinos Koutsomichalis
Music Research Center, University of York
Contemporary Music Research Centre (CMRC)
Faculty of Music Technology & Acoustics - TEI of Crete
www.marinoskoutsomichalis.com
www.agxivatein.com
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