Sub boxes -- if you ask me I'd get the speaker specs and start plugging away in those box builder programs.
Matt can give you specifics but one of the characteristics I shoot for is a Qtc of .7
Your best bass would probably be ported through the 6x9's. The easiest to configure(for decent sound) is a sealed enclosure that is spec'd correctly. Different sized boxes change the sound of speakers...and EVERY speaker is different. They don't have the same specs or measure the same. They're like personalities, no two are alike.
