Hello world, after much research and consideration I have finally decided to become an SSA consumer, I plan on buying a DCON series 15in to run with an Alpine MRP-M650.
I plan on designing and building a custom ported enclosure for the sub, and this yields the question, what is the recommended volume for said enclosure? I know the SSA Store gives recommended box dimensions, and I have seen them for the DCON 12, but the fields are empty for the 15 D: 
Any help is appreciated. My guess would be somewhere around 3-4 cubes? But it's my first build so I feel like I need some reassurance. Thanks

You are thinking correctly.http://www.soundsolutionsaudio.com/index.php/product-information/dcon.html scroll down, and click on enclosure recommendations. They even provide some pre designed enclosures. Nice choice on the sub!

Hah, never thought to check the site itself. Thanks man! I'm looking forward to upgrading from an Alpine Type S

you'll love it

Great SQ, but you can make em get pretty loud too.