We do not recommend modifying the headset cable. Headset extension cords or headset "Y" cables are also not recommended. Extensions should be limited to no more than 15ft due to the possibility of capacitive coupling between the microphone signal and the headset signal which would cause a loss of high frequency response or oscillation.
CAUTION: DO NOT connect microphone ground and earphone ground together at any point.
For the CC-110/220/300/400 headsets we do not recommend modifying the headset cable. The cable placed on this headset is sold as is. Using headset extension cables is also not recommended. Headset cables must have an individual shielded microphone pair. It is not recommended, but can be done .If you want to buy an extension, contact Mike Wilson at www.bigskyengineering.com or call him at 858-484-2409. If you want to build one, please do not make it longer than 15 feet or so. You’ll need one male and one female 4pin XLR connector. Pins one and two should be on a separate shielded pair from pins 3 and 4. Best to use two mic cables and “marry” them together by taping them together every 6” or so… or encase them in a piece of shrink tubing.