Im about to build my first box for these 4 subs. Im going with a sealed enclosure and they will each be in about 1.3 cubes. Does this sound okay? I also have dimensions for 1.6 cubes each..which should i go with. They will be running at 1ohm seeing 1000 watts total for all 4 subs dimensions of the space I have to work with are 47" wide by 36" deep,to window line is about 18"