Hey guys, I'm new to the forum but have been looking into the RL-P's for a long time now. I'm about to buy two 15" RL-P's in a couple of weeks, and I have been looking into boxes lately. Like I said I'm going to be buying two 15's very shortly and I plan on dropping them in a ported box. If I give each sub 3.5cu ft after displacement what should the box be tuned too? Power will be an eD Nine.1 going to each sub. I'll use 3/4" or 1" MDF with bracing and the works... I figured I'd go with an open (non divided) box. The box will be going into the back of a '00 4dr GMC Jimmy... Might go in the '95 4dr Blazer.. not sure yet but I'll be able to fit 7cu ft total in the back no problem. Should I go smaller on the box? 6cu ft??? I'm lost.. Any help on this would be greatly appreciated. I've only got 3 JL10W3v2's in a sealed box with 500 watts now so I'm going to be upgrading the altenator before running all that power, I've got an Optima Redtop under the hood. Thanks guys! I can't wait to purchase my subs.