13
ϕ
= one-half the recording angle,
α
= one-half the angle between the two “virtual microphones”
“Virtual microphones” in an M/S recording, showing the left channel
result (M+S) when a cardioid is used for the M-channel microphone
Extreme settings of the WIDTH control
can lead to unexpected and possibly
undesirable results. A sound source
that is moving from left to right, for
example, will normally be heard in a
steadily decreasing degree in the left-
channel output signal. But if that
sound source crosses past the null in
the polar diagram of the left-channel
"virtual microphone" (see above), its
presence in the left-channel output
signal will begin to increase again. This
will cause it to be located incorrectly
within the stereo image. The signal
will also be out of phase, which can
cause further problems: in a Dolby
Surround recording, for example, this
sound source could be audible in the
surround-channel loudspeakers.
main stereo axis
Increasing ratio of S signal to M signal
(unusable)
mono
Summary of Contents for VMS 5 U
Page 3: ...3 15 16 19 17 18 8 9 10 11 12 13 14 1 2 3 6 7 4 5...
Page 18: ...18 16 Block diagram...
Page 19: ...19 Frequency response curves above without low cut filter below with low cut filter...
Page 22: ...22...
Page 23: ...23...
