Single 21" death penalty, if I decide to do this I'd have Fisher Customs build me a box.

What would you guys recommend as far as box size, tuning freq, port area?

Looking for heavy lows so I was thinking 28-33hz.

Going in the back of an extended cab F150, sub forward port up. Power will most likely be a Rockford T1500-1bd.

Edited November 13, 200816 yr by 5.4SPL

id say around 10 cubes net, would work nice

Better go really thick on the sound deadening if your port is gonna be facing up......heard a 21" last weekend in a Z71 and his roof sounded like crapola......he had about 1200 watts on his and it sounded ..ok.....it only played lows and then below that......wasnt very loud to me though...but could have been his setup.....

roof rattle is chevy's ordeal, heard many systems in ext cab chevy's that had roof rattle, ford doesnt have that problem, my 18" btl on a sundown saz3000d doesnt make my roof rattle, sub up port is side firing, only problem that stinks for us is the cabin vents before the bed, they are like flaps so all you hear is flapping if you're outside the truck.

ummmm k?

All my boxes are port up, my roof doesn't rattle like the Chevy's do (that I've seen).

Ten cubes sounds nice. How about for an 18"?

Edited November 14, 200816 yr by 5.4SPL

6 to 8 cubes net on average

You should have got a Chevy! lol rolling the windows down makes a HUGE difference in all my truck setups. Never heard a setup in a ford before though...

i have a 06 gms ext cab 4door...the roof was about to fall apart..put 5 layers of rammatt on the rear section and 2 on the front and its perfect...also pulled the bed off and put some sheet metal over the cab vents to seal her up...only down side is that i have to run my defrost alot now b/c of little/no ventalation...i think i might run 2 IADP 21's in 20 cubes net walled off...