Taperssection.com
Gear / Technical Help => Microphones & Setup => Topic started by: OhioHead on October 20, 2015, 12:44:12 AM
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Ran my Oktava 319's in the taper section @ the SCI show tonight, picked up "a bunch" of talking behind the TS, anybody who runs LD's for open aud taping have have any suggestions for a "baffle, etc." to prevent the back pick up? I was about 9.5 feet tall.
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Run hypers when possible
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If you're picking up unwanted sound behind the mics hypers might not solve the problem as they have a rear lobe of pick up, too. Might just have to go up higher with the mics.
A venue I used to record a lot of shows at had a pool table in the back but directly in line with the mics and the stage & when I ran hypers I would pick up every time someone broke a rack of balls. Not so with cards. Luckily they 86'd the pool table eventually.
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Well--the thing is, a microphone's polar pattern is three-dimensional, and cardioid is quite a broad pattern all around--not just in the horizontal plane. A microphone with a narrower pickup pattern is narrower all around, not just in the horizontal plane.
Yes, a supercardioid/hypercardioid has a rear lobe BUT it is markedly less sensitive than the main, front lobe (by >11 dB for a true supercardioid, 6 dB for a true hypercardioid, and something in between for microphones whose patterns are in between), and once again the rear lobe is also narrower in both the vertical and horizontal plane than the main, front lobe is. So all in all, a supercardioid/hypercardioid will pick up distinctly less room sound, as compared to on-axis sound, than a cardioid--despite the presence of the rear lobe.
--best regards
P.S.: The attached composite shows two nice pseudo-three-dimensional polar graphs as published by Beyer. This may help to visualize the situation.
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too bad there are no 3d representations of hyper and super patterns in http://taperssection.com/reference/images/polarpatterns/ as I find the omni and card .gifs make it easy to visualize the way those patterns translate from 2d to 3d (for me better than the Beyer-sourced drawings Mr Satz posted)
< though the following "by >11 dB for a true supercardioid, 6 dB for a true hypercardioid" makes me think the two patterns are either mislabelled or my understanding of them is faulty >
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too bad there are no 3d representations of hyper and super patterns in http://taperssection.com/reference/images/polarpatterns/ as I find the omni and card .gifs make it easy to visualize the way those patterns translate from 2d to 3d (for me better than the Beyer-sourced drawings Mr Satz posted)
< though the following "by >11 dB for a true supercardioid, 6 dB for a true hypercardioid" makes me think the two patterns are either mislabelled or my understanding of them is faulty >
^
The gifs at that link (http://taperssection.com/reference/images/polarpatterns/ ) are mislabeled. Hypercard is closer to figure-8, supercard closer to cardioid. >11 dB less sensitivity at 180 degrees compared to 0 degrees on-axis for a true supercardioid means the rear lobe is smaller than a true hypercardioid with a 6 dB difference.
Also- since two microphones are being used together as a stereo pair rather than individually, when thinking about pickup of room sound and sound arriving from directly behind or back quadrants, it can be more useful to consider the combined pattern of the two overlapping each other. In that sense, two cardioids, angled apart from each other in a typical stereo pattern, produce something resembling a single subcardioid pattern when overlaid upon each other in combination - there is no clear rear facing "null" in their combined pickup. Two supercards in a similar stereo configuration combine to resemble something resembling a single forward facing cardioid.