hey guys,
this is a mod to use the M$ wireless headset transmitter on the mixamp with the xim3
the mod has the following advantages:
-no robot voice because it's not connected to the xim3 
-no aim-moving on the xim3 if anyone speaks loud into the mic
-no headset-cable nedded to the controller on the xim3.
-you have a mic on / off button and can use it with any headset which is pluged into the mixamp.
-no batteries need to power the wireless headset
- you speak and hear the voices in your Ad700 (or whatever headset you have connectet to your mixamp)
without the mod:
headset --> cable --> mixamp --> cable --> controller --> cable --> xim3 ---> cable --> xbox
with mod:
headset --> cable --> mixamp -->wirelesstransmitter --> xbox 
the mod is much easy,
all you need is a microsoft wireless headset
and a cable from the microsoft wired headset (or any other 4-pin cable with a 2.5mm jack)
if it's done it must look like this picture
the 2,5mm jack goes to the mixamp and the usb goes to any usb-port to power it

you don't have to speak in the wirelessheadset, you speak an hear the voices normal in your headset which you have connected to your mixamp.
now lets start the mod
open the wireless headset
there are two screws on the right and left of the bracket
how it looks open you can see here.
http://forums.xbox-scene.com/lofiversion/index.php/t560135.htmlfirst take the charging cable (from the wireless headset) and cut off the connector.
you see a black and a red cable (black=ground and red= +)

now we goes back to the wireless headset
on the battery pack you see a yellow and a blue cable (blue=ground and yellow= +)
Remove the battery and solder the usb cable on these two cables from the pcb
(black to blue) and (red to yellow)
remove the speaker from the wireless headset.
you see a red and a black cable (red= + and blach= ground)
remove the mic cable like in the picture
you see ab black and a white cable (black= ground and white= +)
now we open the mic on/off switcher from our wired xbox-headset

if its open, solder all cables from the wireless-headset pcb to this pcb like in the pictures


now it's done.
test it, isolating it, (if you want fix the soldered joints with hot glue)
assemble it and have fun

hope you can understand this TuT, my english is not the best...
google translator ftw^^