moop

iTrader: (1)

i'm trying to design a sub box with 2 ports aiming straight up (will be aiming where 6x9 speakers here in my back deck)
the problem i run into is that with 3" round ports, my port velocity comes out around 28m/s and the lengths are 20" each.. which will not fit

i'm open to suggestions if anyone could help out

oakley1984

slot port it

moop

iTrader: (1)

i would, but being a fairly large sedan, i want to direct the ports through the holes where the rear speakers were

Micardio

do you have a diagram to show what your looking for. Also box size and tuning freq.
If you're using pvc pipe for the port I would get some 45deg joints. 90s are too sharp. Also flare the ends to reduce port noise.

DDnut

iTrader: (6)

3" ports are not alot of good for anything over 8" subs.Try 4" or 6" at 12"long.How ever it is hard to say without sub size and box size

moop

iTrader: (1)

it's a 12" rockford fosgate t2, i ended up just building the spec enclosure for now

DDnut

iTrader: (6)

well for daily driver its likly best to stay with that, as RF do do some R&D for boxes to find the over all best box.
And 3" is real small for that sub

moop

iTrader: (1)

it's almost disappointing trying to make this car sound good and loud :P

zimme

Could you just do 4 ports instead of 2?

DDnut

iTrader: (6)

yes but they need to be a good bit longer to stay tuned the same
also leaving less box space or going to a bigger box