So, I'm probably going to build my own speakers but I do have a question. My mobo has separate outs for LR, rears, and sub/center. My questions is, is there software that can filter the channels so that I can use the sub/center channel directly to an amp without needing an external crossover? Basically, I need something that can set the sub out to work at say 120hz or below, and the fronts at 100hz and above. Anyone know of anything like this?