need help with doing ports

[philrab]

I was thinking making the box out of .5 mdf that should give me 2.3 or so,if this isn't enough room I can go l-55in h-16in td-9in bd-10, i just want to know will the 2 sd-2 10 slam harder then a beefy 12 on 1500rms

2.3 cubic feet is still marginal for two of those 10's ported. I just think you're trying to fit 10 pounds in a 5 pound bag.

I don't know if a single SA12 will live with that much power man, now if you look at the X12 maybe, can't say for sure. I can say that in your limited space, you're going to end up building too small a ported enclosure for a pair of SD-2 10's, or a righteous box for a single 12. A box built to the proper dimensions will usually beat out one built too small/without enough port area.

I'm confuse now so 1 12 be better then the 2 10's. what about 2 sa 8v2 I heard those things are beasts

You're looking for a simple answer, and there isn't one.

All assuming the dimensions you posted:

A. You run 2 10's. More cone area, they can take the power you're talking about with the amp you mentioned. This would be louder IF you build an enclosure big enough for them. The dimensions you've indicated aren't big enough for a pair of 10's in my opinion. The only exception would be build a 2 cubic foot box, and run an appropriately sized external port, which I don't know if you can with your space.

B. You run 1 SD-2 12. Less cone area, probably not as loud as a pair of 10's, more than likely will not appreciate being grossly overpowered like you're proposing with that amp, BUT you do have enough space to build an appropriately sized box.

C. A pair of SA-8's will require 2 cubic feet of airspace net ported. You do not have enough space to build an enclosure to meet that need. See A.

With the space you have, I'd look hard at a single SA12 or SD-2 12. Both require 1.75 cubes, leaving you a little room (but not much) for port displacement. An SA10 or SD-2 10 would be money in that amount of space (easily enough airspace for them.) Does that make sense? I think you're just trying to cram too much woofer into too small a space.

Of course, if you wanted to run a pair of subs sealed, then we're in a whole different ballpark, but you said ported. Ported enclosures take up a LOT more space than sealed.

[justin0943]

okay maybe this be better here a pic of the length of what i have

[philrab]

What is your point?

[justin0943]

What is your point?

just showing a pic of the room I have I can put in external port to make up the room that I don't have or I just build a box all the way like I said man I'm no box expert I can build it but can't tune it so need all the help I need for the sd-2 10's

[philrab]

Well, if an external port is an option, then yes I think you can do a pair of 10's. Sub displacement may make you a little small on airspace, but with an external port you'll be in the ball park.

So you need a design, now that we know you're in the ballpark for airspace?

[justin0943]

Well, if an external port is an option, then yes I think you can do a pair of 10's. Sub displacement may make you a little small on airspace, but with an external port you'll be in the ball park.

So you need a design, now that we know you're in the ballpark for airspace?

yes think you for all the help, now how should I do the port like how big of diameter,total lenght,how far sticking out,how much in the box

[philrab]

I'll be somewhat general, since I get the impression you already have experience building sealed enclosures, and just need help with the ported aspect of them. If that's an incorrect assumption, please let me know.

I'd build the enclosure to your max dimensions (pasted from above: h-16in l-35in top depth-9in), that should put you right close to 2 cubic feet, a little less with sub displacement. Sundown recommends 1 cubic foot each, so that's got you in the ballpark. You could also invert the subs so that they aren't digging into your airspace, which would help if you like the look. You're going to need the ENTIRE port to be external, as any amount of it inside the enclosure is going to eat airspace that you can't really afford to give up. A 6" round port, or 6" aero would be my recommendation (16 square inches of port each, 32" between the two), or a slot port with 32 square inches (multiply length and width, when the result is 32" there's your money, like a 4" x 8" slot port for instance.) I'm at work and can't use Torres calculator (my preferred tool) but I'm coming up with 11.25" long on the port (I do not, and would not, take that as gospel until someone has run this all through Torres calculator, but this gives you some direction and idea t least.)

Here's a link to some pics of external ports, so that you can get an idea of what you've got to do. Personally, I think port inside the enclosure looks cleaner but for what you want to do I don't see another way. https://www.google.com/search?q=site:www.stevemeadedesigns.com+external+port+examples&safe=off&biw=1536&bih=732&source=lnms&tbm=isch&sa=X&ei=5a0JVKjjMO3bsAS44IHQDw&ved=0CAYQ_AUoAQ#safe=off&tbm=isch&q=site:www.stevemeadedesigns.com+external+port

[Ritch40]

id also run those numbers thru something such as winISD (or a similar software of choice) just to get a rough idea of port velocity as well. you will want to try to keep that under say 60 feet per second.

[philrab]

id also run those numbers thru something such as winISD (or a similar software of choice) just to get a rough idea of port velocity as well. you will want to try to keep that under say 60 feet per second.

That port area suggestion is straight from Sundown, so I'd imagine it would be okay, but yes WinISD wouldn't be a bad idea.

Like I said, here at work, I get a bit of time here and there to surf and lend a hand, but I have NONE of my enclosure design stuff available here so I'm relegated to either doing the math longhand, or using a free online box calculator (that I do NOT trust 100%.)

[Triticum Agricolam]

...A 6" round port, or 6" aero would be my recommendation (16 square inches of port each, 32" between the two), or a slot port with 32 square inches (multiply length and width, when the result is 32" there's your money, like a 4" x 8" slot port for instance.) I'm at work and can't use Torres calculator (my preferred tool) but I'm coming up with 11.25" long on the port (I do not, and would not, take that as gospel until someone has run this all through Torres calculator, but this gives you some direction and idea t least.)

...

A 6" round or aero port has 28.27" sq in of port area, not 16". Not sure where you got that number, but anyway if a 6" round port was used you MIGHT be able to get away with just using one.