This is just a bad idea, plain and simple. Firstly it is never a good idea to mix different types of amphetamines, however I guess if you keep the dosages low all around the harm may be reduced. This thread screams 'harm reduction' in that I hope some people start chiming in on the risks of smoking methamphetamine after having taken adderall.
I wouldn't smoke much meth if I were you, it also seems like you have no fear of this combo, that one may 'cancel' out the other. Did it cross your mind that this combo could be very dangerous and bad for your heart? Do you know what a stroke and heart attack are? Are you aware that these drugs may increase each other's effects, with more likelihood of side effects that may not be very pretty?
What was the amount of adderall taken, obviously '2' but were they IR or XR? What size?