I just got myself a RE xxx 12" and am planing on building a box for it. I will be running it with a Hifonics bx1605d (1600 rms at 1ohm) I was leaning towards ported so i can get some real good lows. Now how big should i make the box and what should i tune it to? I have about 4ft^3 to work this and want this sub to hit like a champ. any help would be great.