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7th February 2010   #77
Tom McC
Gear maniac

Joined: Apr 2009
Posts: 208

Quote:
 Originally Posted by NorseHorse Ah ha. Yes, I think I'm getting closer to what I'm trying to say...... .
Norsehorse, to expand on Didier's comments and give you something to hang yourr hat on, I enclose below some calculations for the 'virtual' XY mic patterns that result when you run MS using an ideal cardioid ("0.5 + 0.5cosX") with a Fig-8 of the same sensitivity ("0 + 1cosX")

Three scenario's are shown: for M/S mix weightings of 2:1, 1:1, and 1:2 (i.e linear ratios, e.g voltage). And the patterns for cardioid, Fig-8, and hypercardioid ("0.25 + 0.75cosX" are included as reference

By inspection - hope table does not get too munged - you can see that a 1:1 mix of M and S equates reasonably closely to hypercardioids with an X-Y included angle of ca. 127
°. Also the polar patterns of the virtual mics change with mix weightings, but are never cardioid (except, of course, for the tivial case given by Didier)

I don't know if you dialled in similar hypercardioid patterns and angles when you used your Schoeps CMTS mic, but if not, then you are comparing apples with oranges, and your conclusions may be a bit premature and simplistic.

regards,
Tom

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Mic patterns:
Virtual XY mics Reference mics
'2M+S' 'M+S' 'M+2S' Card Hyper Fig-8
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Included angle,
° 90 127 75 - - -
of virtual XY
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Off-axis
Angle Off-axis level drop (-dB)
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0° 0.00 0.00 0.00 0.00 0.00 0.00
10° 0.08 0.09 0.11 0.07 0.10 0.13
20° 0.31 0.37 0.43 0.15 0.40 0.54
30° 0.71 0.84 0.99 0.60 0.92 1.25
40° 1.28 1.53 1.81 1.08 1.68 2.31
50° 2.04 2.46 2.94 1.71 2.71 3.84
60° 3.01 3.68 4.47 2.50 4.08 6.02
70° 4.23 5.27 6.55 3.47 5.91 9.32
80° 5.75 7.35 9.50 4.63 8.40 15.21
90° 7.66 10.20 14.19 6.02 12.04 inf
100° 10.10 14.47 24.04 7.68 18.43
110° 13.40 22.78 9.66 43.72
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