I know this may not properly answer your question, but hopefully it'll help. I ran my Gcon 12's sealed in 1.5 cubes per sub for quite some time and was very pleased with their sound quality. I wanted more output though, so I emailed Mark from SSA regarding box dimensions because their site did not yet list a pre-designed enclosure. He recommended building a box to the same dimensions as their pre-designed dual Icon enclosure (4 cubic feet net with a tuning of 33hz IIRC). I built it and have been very pleased with it for the last few months, running off of 1500RMS for the pair. It's not quite as accurate and musical as the sealed enclosure however it is still very good sound quality, and the difference in output is easily worth it. They play very low in this box and get respectably loud for 12's, while still keeping up with my rock/metal/rap/dubstep. Their website lists an easy to read box plan. Hope this helps, good luck
