Im not sure how to phrase my question or what to google, but does anyone know how this feature is implemented (eg a simple example circuit):
On some audio mixers, if only the left channel is plugged in, the audio from this input will be split across the left and right channels. However if both left and right inputs are connected, then the audio from the left and right inputs will remain separated on the left and right channels.
For example, a behringer q502 mixer has this functionality, it is marked on the mixer as "mono L"
I know this could be implemented by having a separate switch to toggle between stereo and mono inputs, but im curious how this is done by simply plugging in a TRS cable.