I am using these programs to try and design a sealed Shiva Sub. The numbers I get between the 2 programs for a -3db down point is way different. I checked and made sure the sub parameters are the same for both. This is my first attempt at a DIY sub. I want the deepest bass extension I can get with a sealed sub. The box will be 16"x16" by ?? height. The height will be adjusted to what it needs to be to get the box volume I need. I assume I want the biggest box that is feasible say around 3ft tall in my case. Why are the numbers between the programs so differnt?