being new to this whole field im in need of some answers:
i just shot some footage at cousins birthday party and everything was fine until they had a so called ROAST and thats when the audio was all over the place [some talked louder than others] i was lookin at the senn g2 system which has the lav but i may need at times [such as that case] a hand held mic - my question is will this system be expandable to both mic 's? - trying to figure out if both can be used at the same time or its either or - i see that it comes with an plug on transmitter which is why i wondered if both can be used together.

all advice is greatly appreciated

oh and i am shooting with the canon XL2 and currently using the stock shotgun mike included w/camera

It's either/or if you only have the one receiver. You can buy a separate receiver and then use both the original transmitters, set to different frequencies.