[quote name='sugrals']The manual states you need a 360 controller for each USB mic you plan to use (unless you have one of the mics with controls built into it). So if you have 2 controllers and 3 mics, guess what?[/QUOTE]
I'm pretty sure it does not say that, but says that you only need one controller to run all vocals.
Then again, I only read the thing when I bought the game on the 8th (woo broken street date).
EDIT: no, it certainly does not say that, I remember the controller spec listing the three buttons you use on the controller to adjust sensitivity on each individual mic.