dude you have to give MORE INFO... yield can be very strain dependent.
If I was growing white widow in there with two plants I would get CLOSE to a pound(~13-14oz). 6-7 ounces per plant, but then again most people would probably get somewhere around 6-10 ounces with the same white widow. Modifications I would make to attain this would be more light, convert to aeroponic, two oscillating fans, different nutrients, co2, UVB lights(trichome development), maybe more ventilation to account for the more lights. As an experiment for my grow that I will be attempting would be foliar feeding with molasses as aero/hydro units don't like clogged pipes(molasses can add ALOT of weight).
I have never grown at my place, but have been the main person caring for plants and designed their grow rooms at two friends' place as well as helping out other friends on their grows for the past two-three years. I am planning my "first" grow at my place right now.
You have to help us with more information so we can help you better.
-pot