Thread: Fascinating MS
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Scott Dorsey Scott Dorsey is offline
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Default Fascinating MS

Gary Eickmeier wrote:
"Scott Dorsey" wrote in message
...
Gary Eickmeier wrote:
A possible new problem has come up with MS, namely some imaging anomalies
at
different frequencies. When I do my stereo test and even during a
performance, I have noticed that higher frequency percussive sounds will
image in the center more than at left or right. Like, the drum set is at
stage left, but there are some pings and other sounds that come from the
center.

Is this some well known principle, or fault, of MS? Ever heard of it?


It's a room problem. Move the mike.


Great responses - thanks to all. I will try some of the tests you suggest.
Could well be a mike problem, changing the M to S ratio with frequency.


You're using two identical mikes, so the response should be the same,
right? It's true that if the side mike has poor high frequency response
off-axis, or is just soft on top, that high frequency things will collapse
into the center of the soundfield. I experienced this with a 77DX
combined with an omni condenser, back when I was a student.

But I'm inclined to think you have reflection issues in your room.

Don't know what the test results might be, but all I can tell you is that I
am using the Audio Technica 2050 variable pattern mikes in Fig 8 pattern.
These are reasonable quality for a beginner like me and I would expect that
would work reasonably well, and maybe my MS mix isn't quite perfiect yet.
And BTW the same phenomenon holds true looking at the lissajous pattern, or
phase response window in Audition, so it is a recording problem and not so
much playback - but I do realize how the rear speakers can affect perceived
frontal direction as well so I will do more testing in stereo only.


Measure it and see. Set up the mike outside, start recording, then walk
a circle around the microphone jingling a set of keys and calling out where
you are. If the high frequency response varies with position, you'll be
able to tell it from just a drop in amplitude overall.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."