David Pickett wrote:
>
> Perhaps I was not clear. Take 2:
>
> It seems to me that Sampo claimed that the omni from a double capsule
> mic is not the same as the W signal obtained by processing the ouputs
> of the four mics in the A-format tetrahedral array, and I would
> agree. However, the former can at least produce an omni in one (i.e.
> the horizontal) plane -- which i what I want. So the question really
> is whether X and Y derived from the tetrahedral array are different
> from those that would be obtained with two horizontal figure of eight
> mics. (I dont think that they are, but I am asking for confirmation
> or denial.)
>
> ...Always asuming that the polar diagram are "perfect", which they never
> are...
>
I would say "confirm" ... but happy to hear another view ;.)>
I would also (in a way) disagree with Sampo about whether one can take Z
away from W.
Certainly you cannot arithmetically subtract it (as he explains).
But:
-If you want a horizontal W (say 'W(2)')
-if you are happy to have this 'omni' as having a cardiod polar pattern
(in the vertical plane) -which surely one wants to match the vertical
polar patterns of X and Y (???)
then:
-I am fairly sure you can derive this from a Periphonic B-format, that is
a transformation from
{ W(3), X, Y, Z } ---> { W(2), X, Y }
is possible (and X and Y are unchanged).
(I'm thinking aloud, one should try it first and speak second !!!
If there is anything in this ... then there are two interesting
comparisons that could be tried:
A)
(I used to like this one when I only had four channel playback ... "Never
mind the reverb, hear the vertical placement of the orchestra".)
Discard X, and playback W, Y, Z on four speakers mounted in a square on a
wall facing you ... using either W(2) or W(3).
Though even that 'is not right' as you should be in the centre of the
plane of speakers ...
so:
B)
Try X and Z as pantophony.)
My (very iimited) experience of omni mic's is that they don't specify
vertical polar patterns ....
Michael
_______________________________________________
Sursound mailing list
[email protected]
https://mail.music.vt.edu/mailman/listinfo/sursound
