Assume the picture below:
From inlet port In1 and In2 we can have electromagnetic or acoustic energy entrace single sine wave with same amplitude and frequency. Assume we have aligned the waves to completely destroy each other After two wave summing in summing point (assume summing point has been created approximately perfect with no reflection). Then we sense zero energy after summing point, where the waves have steady state. This rejects energy conservation since it means we after that "summing point steady state output", we will never be able to access that energy. Then have removed some energy from our word at least apparently, though in theory the still present and is bounded together.
What is wrong on my argument? Maybe energy conservation is just applicable for masses and not the waves? I'm electrical engineer and not the physician sorry for weak physical understanding.
I've heard collision of particles can create positive and negative particles, like matter and anti-matter.