Guys, i need a little advice regarding box size. I'm getting a Focal 33 V2 (Polyglass 13 inch) subwoofer. The Focal website listed the "suitable" box size would be between 25-50 litres (sealed). I want to know if any of you have experience with this sub and what box size you suggest (in litres). I need more specific info than "just between 25 and 50 litres" like what the focal website suggests. I'll be powering it with around 350-400 watts RMS and i want it to bump clean and hard. Please help! Thanks!