Is it possible to isolate COM1 and COM2 on a Garmin G1000?
(wikimedia.org)

On the audio panel installed between the two G1000s, there should be a COM 1/2 key. That will enable the split COM operation with COM1 going to the pilot and COM2 going to the copilot.  What avionics are in the aircraft that you have?


  Split COM allows the pilot to use COM1 while the copilot uses COM2. This proves very helpful for talking to an FSS en route without leaving the ARTCC frequency. Pressing the COM 1/2 key on the audio panel turns on Split COM mode (Garmin).