HEADSET/SPEAKER HELP

Hello,Can you tell me how to set the FSX sound controls to be able to hear both FSX sounds AND FS2Crew sounds through the speaker AND be able to speak through the mike.so far, I tried several configurations and FS2Crew will only come through the headset. Also sometimes FSX sound come throught the speakers and sometimes only through the headset.I just want to be able to hear both through the speakers if I choose.I use FSX, Windows Vista, Logitech USB headset,Thank youJ L