cerwin vega V max?

I have been out of the audio scene for almost 5 years now. I am building a system. I've always run vegas powered by orion amps.I just bought 4 vega V max 12's, dvc. The spec sheets say to use either 1 foot vented or .75 sealed. I have never ran a vega 12 in anything less than 2/2.5 foot vented. I called vega and got no help. Does any one have any input on this? I have an ext. cab mazda, and have @ 15 feet of space. I will be using 2 Orion 2150's to push them. Anyone have any input? Thanks in advance

the new Vega Vmax's are nothing like the old school Vega stuff. Less power handling, Less quality, Less loud. Sorry.