Ok so I went with 2 RE10's and they should be getting here this week and I need to build my box. I called RE and asked what I should have for airspace per sub and they told me that they make boxes with .6 cu per sub in a sealed box, which im making. But on the website it tells you for SQ to go with .83 cu per sub. Which one would be better for me. I can go with up to 1cu per but would rather not since its goin behind my seat in a reg cab truck. The smaller the better but plz I need some suggestions. If u need my amp rms its 400 bridged for the both of them.