Thanks very much to both of you for your responses.
Teemuk - sorry about making you post redundant information. I tried a few searches, but I didn't find what I was looking for.
My reasoning on using the headphone jack is simply that it's already mounted. I was thinking I would disconnect whatever is currently feeding it and just tape those wires off and leave them dangling inside the cabinet. Then wire the jack inline as you describe.
Though it may make more sense to just add another jack as you suggest.
Either way, thanks again for both of your help.
Teemuk - sorry about making you post redundant information. I tried a few searches, but I didn't find what I was looking for.
My reasoning on using the headphone jack is simply that it's already mounted. I was thinking I would disconnect whatever is currently feeding it and just tape those wires off and leave them dangling inside the cabinet. Then wire the jack inline as you describe.
Though it may make more sense to just add another jack as you suggest.
Either way, thanks again for both of your help.