This is a simple question, but i can't seem to get my bearings right on it. Consider two speakers at essentially the same point emitting sound waves that are half a cycle out of phase but otherwise identical. Interference dictates that these two waves should cancel out. The resultant wave, now "flat", appears to deliver no energy as it "travels" outward. But this appears the contradict that each speaker is delivering energy to the air as it generates its respective sound wave. Could someone give me a solid understanding of what is really going on? Thanks.