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Caleb9107
08-16-2009, 03:57 PM
Does anyone have any advice in building flared slot ports? I just recently took up an interest in sound systems (mainly subs) and have 2 audiobahn AW1200V's (12"). I have them in a sealed box for now, but I am looking into building a ported box of some kind. Originally I had planned to go with circular ports but after seeing some custom flared ports, I think I am changing my mind to go with something more along that style. I want to go with 2 dual flared slot ports(1 for each sub) and I am having trouble trying to figure up the area and if the flare makes any difference on port volume? I am mainly trying to decide how to design the port (preferrably L shaped) and the flares. The thing that is throwing me off is designing it to still be tuned to around 37 hz with the flare. Not sure how to calculate the flares into port volume. I can supply the specs for the subs and the recommended box dimensions if someone is just willing to try to figure the whole thing up, just let me know and I will post them! If anyone has any knowledge of building this style enclosure I would greatly appreciate you sharing your knowledge with me.

Pioneer~Saturn
08-16-2009, 04:06 PM
Port volume has nothing to do with calculating tuning if youre suggesting that. And having a flared port has almost no effect on your tuning etc, you just simply measure the effective length of the port starting where the port's walls are parallel to eachother (negating the flare pretty much and starting calculations where the flares stop). The 3 things you need for tuning is the port area (height x width of the port in this case), port length, and net airspace inside the enclosure.

If you can tell me those 3 pieces of info for your design...I can tell you the tuning in a heartbeat

dappa5
08-16-2009, 04:07 PM
are you talking about using a bellmouth flare or just rounding the mdf at opening?

Twisted_0912
08-16-2009, 04:12 PM
i think he means something like this...

http://i451.photobucket.com/albums/qq238/Twisted_0912/IMG_3694.jpg

Pioneer~Saturn
08-16-2009, 04:13 PM
i think he means something like this...

http://i451.photobucket.com/albums/qq238/Twisted_0912/IMG_3694.jpg

chyea

Caleb9107
08-16-2009, 04:28 PM
Somewhat like that picture, except i want it flared in both directions for each port!

The flares are going to be kerf cuts in the mdf to bend it and then seal with resin.
This is what I have come up with so far. Does this sound like it would work?

http://img88.imageshack.us/img88/2445/reportcalc.png (http://img88.imageshack.us/i/reportcalc.png/)

This is per sub by the way..

Pioneer~Saturn
08-16-2009, 04:30 PM
If that's for your 2 12's...that is definitely too small imo. After you take away the displacement of the subs and the curves involved in the flares...youre looking to be a good chunk under 3 cubes

And if youve only made an enclosure or two ever, you may want to get your skills up on a couple more simple enclosures or try out a couple that have a single flared port first

Caleb9107
08-16-2009, 04:36 PM
They will be L shaped ports. And also my subs each displace .2 cu ft so right at 2.9 per sub.. may up that a bit.. the factory said 3.3 for more spl type sound. Also, not worried about the building part, my uncle is helping me and has done plenty of woodworking including the kerf cuts so that won't be a problem, just the designing and getting all the numbers to match up!

Pioneer~Saturn
08-16-2009, 04:38 PM
Ok, I thought you were talking about that for both sub...if youre saying that would be for each sub, that would be just fine. And i can layout a design on sketchup so you have a better look at everything if you'd like and I'll double check all the numbers for the specs

Caleb9107
08-16-2009, 04:41 PM
HAHA. Sorry for the confusion there. That would be one cramped box if it was for both! I just decided I would figure up one side on the calculator and then just duplicate it for the other side. So to design my flare, I just draw the flare up and then add in port length?

Pioneer~Saturn
08-16-2009, 05:13 PM
Well, the flare would take away port length if youre asking that

Caleb9107
08-16-2009, 05:17 PM
Yep. So would I need to add that length that is taken away back to the port to get back to my original figures?

Pioneer~Saturn
08-16-2009, 05:19 PM
Yezir. And a general rule of thumb with that calculator, I would add a bit of length to the port and make the enclosure have a good bit more airspace than you want, this way when the sub gets dropped in and (I would suggest doing this as well) a double-layered baffle that the subs mounted to it'll take away that airspace you added and the tuning will raise closer to where you want it. If you design the enclosure with the exact specs you want on that calculator, once you double-baffle it and the subs dropped in, it will be smaller airspace and tuned a bit higher than what you intended.

jamesw
08-16-2009, 05:19 PM
why 2 ports instead of one?. your just going to get port noise more than likely

jamesw
08-16-2009, 05:20 PM
I mean seriously other than looks maybe whats the logic..

Caleb9107
08-16-2009, 05:31 PM
I'll look into that Pioneer! Thanks!

Jamesw- I want one port per sub. I'm not a fan of the single port look and each port will be on the outside edge!

plugitin
08-16-2009, 07:26 PM
i say one port would be better...and yes they are for looks. There not that hard to do...id use a 4 to 5 inch radius to start out with. Space the cuts 3/8 to 1/2 inch apart, and cut 11/16 or so into the mdf.