so i have 3 12"s and an amp that can take all 3, problem is i thought i'd have more room than i do. ideally i'd like 10cf, but i figured only 9cf would fit. After more considerations i'm left with 7cf external dimensions. I'm building this box for a hatchback and i'm really keen to have 3 12s in there but i'm not sure if it would work well. Would you guys recommend going for 3 12s or 2 12s in the same space, the box will have separate chambers for each sub and i'd be sending about 500wrms to them altogether either way.
The chambers will be tuned to 30hz.
My other thought was polyfill, if i put some of that in there would that theoretically increase the volume it sees? Hopefully i can get this closer to 9cf total.