This paper from Ron Stryker and Wes Dooley is worth a read:
http://www.ribbonmics.com/pdf/technique.pdf
If you are new to MS it should explain tons.
Best,
Michael
On Oct 15, 2012, at 8:08 PM, ajustend <> wrote:
>
>
> It definitely seems that the out of phase rear lobe of the MKH50 is what =
is causing my problem. The polar pattern of a standard cardioid seems to be=
much more ideal for what I am trying to accomplish, and since I am new to =
MS recording I failed to realize how the rear lobe of the super-cardioid wo=
uld end up translating.
>
> I figured that the rear lobe of the MKH50 Mid mic would only create a vol=
ume bump in the sounds recorded directly behind (6 o'clock position) the Mi=
d microphone. I did not consider the fact that when decoded the result woul=
d be the same as a pair of super-cardioids in a coincident XY with both of =
their rear lobes pointing across each other diagonally at the 4-5 o'clock &=
7-8 o'clock positions. :)
>
> Thank you for the feedback.
>
> -Justin Mullens
>
> --- In "Avocet" <> wrote:
> >
> > > Here is the test I conducted: Set the microphones up in the middle
> > > of an open field so that I can walk in a full circle around it.
> >
> > Justin,
> >
> > An excellent stereo test.
> >
> > > Here's the problem, when I get to the 4 & 5 o'clock postions (rear
> > > right side) the sound source swap sides and sounds like it is coming
> > > from front left. And the exact opposite happens to the 7 & 8 o'clock
> > > positions sounding like they are coming from the front right.
> >
> > That is what you would expect. M-S gives a good stereo image of a
> > forward object, but at angles where M<S, the image tends to wander,
> > then swap over. What you hear depends on your listening system.
> >
> > The best explantion for what is happening, especiually with an MKH-50
> > / MKH-30 pair, is to look at the polar response diagrams side by side.
> > As you look left and right, the M signal decreaes and the S signal
> > increases. When they become equal (for a particular frequency) these
> > are the full left and full right image positions.
> >
> > Beyond this "sweet image" the decoded M-S goes out of phase, and the
> > image placement is not defined. I usually hear this as a behind image,
> > but it may be just defocussed.
> >
> > The MKH-50 supercardoid gives a narrower front "sweet object" angle,
> > but a larger out of phase rear object coverage. Now the MKH-50 has a
> > rear lobe which is out of phase with the front lobe, so this swaps
> > left and right when matrixed to L-R. As with the front image, an
> > in-phase but reversed rear image can he heard as long as M>S.
> >
> > Increasing or decreasing the S signal moves the extreme L and extreme
> > R object angles.
> >
> > Does this correspond with your walk around test?
> >
> > David
> >
> > David Brinicombe
> > North Devon, UK
> > Cogito cogito ergo cogito sum - Ambrose Bierce
> >
>
>
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