Hello gnome (nickname for ya). anyways, I currently have a subzone pre-fabbed box from 4 yrs ago (before they started building QUALITY boxes) and i have a feeling it is DESTROYING my SQ on my new JL sub. I have never owned a JL sub so I can't say that I know exactly what it should sound like but I know it shouldn't sound like a SPL sub (like my old audiobahns). Just curious if the box isthe culprit and if so, then I am at the right place =) BTW, the jl sub askes for 1.25 cu ft sealed. But I want to go ported because I hear its a MUST! I have no idea about the frequency or even how its measured. I hear that lower freq. means SQ and higher freq. means SPL. is this true? Well, I filled out one of your quote forms and let me know what you can do.