View Full Version : help figuring out port on box - 5.5-8.0 / 35-34 hz

11-29-2008, 09:50 PM
my car is 1984 corvette.

I need 5.5 to 8.0 cubes (not including port) for re sx 18
tuned to 35 or 34 hz - as RE sugests...
woofer displaces .22 cubic foot.

max width is 32"
max leingth is 27"
max height at rear is 17.5"
max height at front is 19.5" - and id like to keep it around 18 or so.

if my box ends up being
32 wide / by 27 long / by 17.5 tall rear / by 18" tall front
= 7.31 cubic foot ( using 3/4" wood )
minus sub .22 cu = 7.09 cubic foot
and then factor in a fiew small braces internaly to stop flexing = ? ?

how the heck do I figure out its port - and how much volume port takes up?

ive built a fiew boxes so far - slot ports - and diddnt realley pay attention to how low I was tuning them to - but this time I would like to do it right
now that I have a sub actually worth wile to use in it.

any help is apreciated. - im good with tools, and am a carpenter by trade
so making the box is eazy, just figuring out its tuning is hard on paper for me.
thanks to all in advance for any help you can throw my way.

SPL Blazer
11-29-2008, 09:53 PM
Try these links.

This one has a calculator to find your volume... Box calculator (http://www.the12volt.com/caraudio/boxcalcs.asp)

This one has a good port calculator...Port calculator (http://www.carstereo.com/help/Articles.cfm?id=31)

11-29-2008, 10:19 PM
thanks, I think those sites told me to make 34 hz tuning,
make slot port 32" wide like the box is - 4" tall opening of port
and port is to be 15.08" long.

that demention takes up 1.16 cubes of internal space from my 7.09 internal already
leaving me with 5.93 cubes actual space for sub.
re recomends 5.5 to 8.0 - so im on the small side -
do yall think it will do ok in 5.93 cubes - or should I try for more?

my car is verry small inside - if that matters at all.

SPL Blazer
11-30-2008, 11:52 AM
Less power for a larger enclosure, more power for a smaller one. As long as your within the manufacturer specs you'll be fine.