5.1 audio switch without popping noises
The addition of the capacitors (“AC-coupling”) will solve the problem of different DC offsets that your sources boxes may or may not have. If you use a non-polarized electrolytic capacitor you don’t have to use a polarized capacitor and guess which way the DC offset may be.
This should solve any pop when switching between two idle sources with DC offsets but won’t do anything to lessen the blow when switching abruptly between two active signals.