Re: box noise........
Well if your sub isn't scrwed down i think you answered your own question.
Actually, your box is probably experience a tremendous amount of turbulence because the air doesn't have eyes and is problably not seeing that extra chamber before it goes out the port. Thats why.
Morel Tempo 5 Components
PPI i350.2 front amp
SSA Dcon 12" in 2.25cf @ 30hz
Alpine MRV-M500 sub amp
Patfitz9,Farkel,PowerNAudio,Qtrhorse,theCybe,Kicke R_TauruS,SWEET06CAMRY, mike dressure,vernisog, Racerx250, iceteebonee