WVGR was forced to downgrade to a mono signal at 20,000 watts, but resumed broadcasting from its own tower in the fall of 2006.
WBLK went from a mono signal to stereo in 1974.
The technology is similar to parametric stereo, in which a mono signal is recovered to stereo.
For example, while a mono signal is played, the strong correlation to the center channel triggers the output volume of the left, right and surround channels to be lowered.
By combining multiple "pan-potted" mono signals together, a complete, yet entirely artificial, sound field can be created.
The output can be routed as a single summed mono signal to an amplifier or recording console.
Composite video connector including S-Video and mono audio signal (compatible with C64)
If the two output buses are further combined to make a mono signal, then a pan control law of -6 dB is optimum.
As for mono signals, a half-inverted signal would be reduced to (near) silence.
Fly guitars feature a stereo output jack, allowing the piezo and magnetic pickups to be sent to different amplifiers, or blended into a mono signal.