port area for 12" TC9

[mat3833 10+ year member]

im trying to figure out a good port area to aim for for a 12" TC9 when tuning to 28-30hz. max enclosure dimensions are 16T 28W 14D, which nets me about 2.9 cubes gross. not sure what actual driver displacement is so ive been using .12 just to be on the safe side. so far ive come up with 14T 28W 14D with a 12.5X1.5" port 28" long. this gives me 1.98 cubes net with a tuning of ~28hz, a 1:8.33 port ratio and 18.75" of port area. im thinking i need more port area, but the only way i can do that is to go to 16" tall and make a 14.5X1.5" port 28" long which puts my port ratio over 1:9.

any help would be appreciated. getting the wood cut tomorrow.

Matt

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[ciaonzo 5,000+ posts]

You can't just go from 12.5x1.5 up to 14.5x1.5 and keep the same length, that changes tuning and pushes it higher. To keep the same tuning, you will also need to lengthen the port if you increase area.

Thought you were going sealed with this? 1.98 net will be too big of you plan on putting real power on it. 1.2 to 1.5 will be best to keep excursion under control.

 

[mat3833 10+ year member]

i spent some time doing some modeling on a friends computer and im not sure i want to stick with sealed. the 14.5" X 1.5" port goes along with making the height 2" taller. its odd but torres says that the tuning will be ~28hz.

Matt

 

[mat3833 10+ year member]

dbl post

 

[ciaonzo 5,000+ posts]

Gonna be loud. Just be careful, that's not a stiff suspension. Don't put it in an enclosure that's too big because that bish strokes. Need to keep good control on it.

 

[mat3833 10+ year member]

im having trouble keeping port area up and port length down. lol, i may end up just doing a **** 6" aero...

Matt

edit, would a single 4" aero be enough port? if so i could seriously cut the size down on the box. im so **** undecided on this its not funny. i just dont want to waste the wood on a box that i dont think sounds decent. especially since ill most likley be stuck with it for awhile.

 

[ciaonzo 5,000+ posts]

Nope. Go with the 6" or use a PR. Based on what you told me you were after, I would try sealed first.

 

[mat3833 10+ year member]

lol, im PMing you now.