Getting prepared to start building the sub enclosure for my car. After taking measure measurements for the size of the SEALED enclosure this is what I've come up with. By the way, I'll be using dual MM2124's wired as a 2 ohm load which according to Polk suggest an air space of 0.88 cubic foot per sealed enclosure. After measuring the space I have to work with the measurements are as follows: 35" wide, 15" high and I can go as deep as I want but I prefer to keep it under 9". After calculating the internal volume I've come up with roughly (per enclosure) 13" high x 16" wide x 7.5 deep / 1728 = 0.90 cubic foot. The sub enclosure will roughly be a shaped as a square filled with poly fill. My question is, should I make the enclosure's internal volume larger and if I did, would I benefit anything from it. I had planned on going by the recommended Polk specs but I just wasn't sure if anyone could tell me what a larger internal volume would do. Thanks for your help in advance.