i need a genius with

[jbl_marshall21 10+ year member]

winISD Pro to figure what a box that is 3.4 cubes with 2 3" ports that are 22 inches long be tuned to? anyone is welcome.

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[Randy Savage 5,000+ posts]

About 21.5 Hz...

 

[ShaunMac 10+ year member]

Yeah I got 21.52Hz. LOW LOW!

Good for communicating with whales //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[tommyk90 5,000+ posts]

D*mn, i got 21.3 with winisd. Is there any advantage to having pro over the regular one?

 

[paikiah 5,000+ posts]

Originally posted by tommyk90 D*mn, i got 21.3 with winisd. Is there any advantage to having pro over the regular one?

Jmac strongly recommended not to use winisd, and to upgrade to winISD pro. Not just Jmac, but a lot of thoers when I first came onto the forum. I guessing a hundred people can't all be wrong.

Besides, I used jmac's specs on a box and sounded superb.. only problemwas that I over estimated the size and the box turned out to be too big for my car.

 

[tommyk90 5,000+ posts]

Originally posted by paikiah Jmac strongly recommended not to use winisd, and to upgrade to winISD pro. Not just Jmac, but a lot of thoers when I first came onto the forum. I guessing a hundred people can't all be wrong.

 

Besides, I used jmac's specs on a box and sounded superb.. only problemwas that I over estimated the size and the box turned out to be too big for my car.

Downloading pro right now. Thanks.

 

[jbl_marshall21 10+ year member]

Originally posted by Jmac Dual 3" ports is nowhere near enough port area ...

english for a dipshit plz. is that not good. u helped me design the box i have now and i was going to take out the divider and just buy one ed k for the box so i am wondering the tuning.

 

[jbl_marshall21 10+ year member]

would adding more ports help? i am wondering what the problem is the ports that are in there right now. y would a larger port like 4" help? so the tuning comes out at 21.5. ok well i want it low like that. too much m/s or whatever that is called.

when i reread this it sounds like i am mad but i'm not, sorry if it sounds like i am

 

[jbl_marshall21 10+ year member]

Originally posted by Jmac Adding more ports would help, as it adds more port area (i.e. three 3" ports would have a port area of ... 3*3.14159*1.5*1.5 = 21.2 square inches against two 3" ports, which have a port area of ... 2*3.14159*1.5*1.5 = 14.14 square inches). However, the amount of port area you need is based upon 4 things ... Tuning, net box volume, power, and sub area

i want it tuned low. like below 25. second the box volume without displacement is 3.4 cubes. the power will be 380 watts rms. the subwoofer is ed k 12.14. 12" svc 4 ohm.

 

[jbl_marshall21 10+ year member]

how long should the 3rd port be to have a low tuning frequency? i still have 3 inch pvc left so i will use that.

 

[ShaunMac 10+ year member]

If you use 3 3" PVC ports and tune the enclosure to 22Hz

All 3 PVC ports need to be around 32.5" long.

 

[jbl_marshall21 10+ year member]

Originally posted by ShaunMac If you use 3 3" PVC ports and tune the enclosure to 22Hz

All 3 PVC ports need to be around 32.5" long.

holy ****. i don't feel like talking to much right now. but uh i won't be able to fit 32 inch ports in my box. well i don't want to anyway. jmac if u ever read this again how much port area do i need?

 

[jbl_marshall21 10+ year member]

Originally posted by Jmac You could probably get away with dual 3" ports if you were to tune it that low ... And considering I don't have a calculator on me right now (extremely rare), I'd estimate that they need to be about 18" long to get ~25 Hz tuning with a box of that size. You might get a some port noise around tuning frequency, though ...

would i need a ssf for 25 hz?

how much port noise do u think i would get running one 12' k with like 380 watts? thanks for the help

 

[paikiah 5,000+ posts]

Originally posted by jbl_marshall21 would i need a ssf for 25 hz?

 

how much port noise do u think i would get running one 12' k with like 380 watts? thanks for the help

marshall, you should learn to use WinISD pro man...//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

You can also calculate what the ssf level needs to be on winISD by checking the cone travel and if it goes over peak to peak xmax, that's where you need to have a ssf.(Maybe a little higher, to be safe.. dunno if the ssf cuts off at a steep slope or not, so...)

 

[jbl_marshall21 10+ year member]

thanks guys. yea i know i need to learn how. guess i will when i get bored enough. thanks again Jmac.