I was having a basic 1.25 cu ft box built by Elemental Designs with one brace for an SW-12B, but a 1.5 cu ft SW-12-04 design was built instead. I already had a spare 150W amp and bought the SW-12B, so even thought I have upgradeitis, I don't want to buy an SW-12-04 and a servo amp right now. However that could be a future upgrade though and this is a better enclosure than the one I ordered. I have one sheet of no rez to use. Can I just put something in the enclosure to take up the extra .25 cu ft? How will the sound be effected if I use the larger enclosure? I don't want mount the driver and test it just yet as I can still send it back and get the smaller cabinet built. Thanks!