first off i have an 18" fi q with the bp power option and a hifonics 1610d amp. its in a focus, and it will b in a 7 cubic foot box hopefully, but my question is that i want to use pvc ports instead of the normal slot port, i used the winisd program, but either im an idiot, or its really hard to use. i put in my t-s parameters for the q and then i set it to 7 cubic feet and put the tuning at 28 hz. then i changed the porting to round and put in that i wanted to use 2 4" ports. it says they need to be 9.25" each. is there nebody out there that can check that for me to make sure its correct? any help would be greatly appreciated. thanx.

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first off i have an 18" fi q with the bp power option and a hifonics 1610d amp. its in a focus, and it will b in a 7 cubic foot box hopefully, but my question is that i want to use pvc ports instead of the normal slot port, i used the winisd program, but either im an idiot, or its really hard to use. i put in my t-s parameters for the q and then i set it to 7 cubic feet and put the tuning at 28 hz. then i changed the porting to round and put in that i wanted to use 2 4" ports. it says they need to be 9.25" each. is there nebody out there that can check that for me to make sure its correct? any help would be greatly appreciated. thanx.

Why do you think it's wrong? And why PVC?

Here is a great tutorial ... I would advise reading. A great way to learn!

http://mobile.jlaudio.com/support_pages.php?page_id=165

If it is 7ft^3 after all displacements 9.25" for 2 4" ports is about right for a 28Hz tune.

well i wanna use pvc bc i dont have alot of space in the back of my car and i figured the bigger the better right? thanx bromo and old school. i will post picks when i get it done