I bought a Halo 3 Wireless Mic and I cannot get the thing to work. I sync it up to the Xbox per the instructions, and it shows a glowing number 2, because it's the 2nd wireless device synced up, but no one can hear me talking, and I can hear no one else talking. I have turned on the mic before loading a game, during a game, etc. and no luck. Can anyone offer some advice?

I turn on the wireless mic even before I turn on the 360 (with the controller)
Then I power up the 360, the headset syncs up with quadrant 1 (along with the controller).

You should only have Q1 lit. Both the headset and controller should be on that quadrant. The times that I have had the issue you describe (two quadrants being lit) it doesn't work.

You could also try
1 - power up headset
2 - power on console by tray open / or power button
3 - then power up controller

or

read the instructions in the booklet. I went that way first and it worked fine.

Good luck

Skid

I bought a Halo 3 Wireless Mic and I cannot get the thing to work. I sync it up to the Xbox per the instructions, and it shows a glowing number 2, because it's the 2nd wireless device synced up, but no one can hear me talking, and I can hear no one else talking. I have turned on the mic before loading a game, during a game, etc. and no luck. Can anyone offer some advice?

Did you try syncing it to the 1st controller? Give that a try to see if it even works. If it doesn't then I would say it is defective.

Dumb question...There is a player 1 when you are trying to sync it to 2nd controller right?

I only have one controller. If the # means controller it's syncing to, not number of synced devices, that would explain a lot! I followed the instructions in the booklet multiple times, after no one could hear my cries for help as they beat me mercilessly in basketball, I realized the instructions weren't working for me. I will follow Skid's steps, then report back.