I currently have a 2004 Silverado extended cab with an Alphasonik 10" sub in a sealed box. It's something that has kind of been thrown together. In the past i have always built my own boxes but now with this truck it's not as easy putting something together under the seat. I'm pretty set on the Image Dynamics ID12 but in trying to find a box that matches well i'm striking out. Per ID they recommend a 1.25 cu ft sealed enclosure and the closest i'm coming up with is an audioenhancers prefab box that is 1.07 cu ft. My question is will this be sufficient and will polyfill help out also. I'm going for more SPL than SQ but if i get some opinoins that the IDQ12 will be that much better I may go with that but I do heavily favor the ID12. Thanks for any help to a noob.