JOSEPHSON ENGINEERING • C700 USERS GUIDE
Stereo on a Simple Mixer
The simplest way to use a C700S for stereo with a mixer requires only a wye cord built with one of
its outputs reversed in phase. See Appendix C1 for a wiring diagram, this cable is not included
with the microphone. Four mixer channels will be needed. The W and X channels are connected to
the first two mixer channels, which are panned center. The Y channel is connected to an inverting
wye cord; the straight-through connector is connected to the third mixer channel “Y” which is
panned left, the inverted connector is connected to the fourth mixer channel “-Y” which is panned
right. Start with just the W and X channels, trim the channel gain controls so that a cardioid (null at
180°) results when the faders are at equal positions. Confirm this by placing a sound source at the
null and adjusting W and X channel gain for a deep drop in pickup toward the rear. Now move
the sound toward the front of the mic and begin to increase the level of the Y and –Y channels.
Adjusting the relative levels of Y and –Y will shift the image left and right (“pan” or “balance”)
and adjusting the ratio of the Y signals to the W/X signals will adjust the “width” or “focus.”
Using a basic mixing console or digital audio workstation, you can derive all of the channels
needed for stereo, center-channel-stereo, 5.1 or 7.1 surround. In practice, the mixdown or balance
engineer will want to adjust the ratios to produce a convincing sound image, but these basic
relationships for surround are a good starting point:
Left Front = W+X+Y
Left Rear = W-X+Y
Center Front = W+X
Right Rear = W-X-Y
Right Front =W+X-Y
Low Frequency Effects = W (lowpass filtered)
Mixing for Surround
A practical way to derive surround channel mixes from raw C700S W, X and Y signals uses a
mixer or DAW with multiple aux busses. Three busses are sufficient if the channel strips have the
capability of reversing phase from the busses; if they don’t, you’ll need five busses, one each for
W, X, -X, Y and –Y.
If you use digital processing to produce the “inverted” signals, be certain that the DSP doesn’t
introduce unwanted phase anomalies in the signal due to changes in processing latency. Many
digital workstations have variable delay depending on the amount of processing being done. This
would cause shifts in stereo imaging due to differences in phase between the channels.
Summary of Contents for C700
Page 1: ...C700 Users Guide ...
