They are in a 4 cube net enclosure tuned to 32 hz. I do have extra room, but I wouldn't say a lot lol. I do have an extra battery, its a C&D High Rate 110 AH battery I believe, and I have a Yellow top D34 in the front. I have a stock 120 amp alt, and if you have any less I'd recommend keeping the gain down until you have a better one. My electrical is like just enough for this system, so I plan on upgrading it to get it's full potential. Also, when you put a huge box like this in your trunk, make sure to get everything in place first lol. I got excited with mine and started sealing the trunk and realized it was going to be really hard to add trim pieces and such without taking the box out.