Help with ported box for 18" Bl

[46panel 10+ year member]

Hey I dont hardly ever post on here but I am always on here reading. I have never built a box before but figure I got to start somewhere. I've been trying to use winisd but I couldnt figure it out so I used the one of SSA but I wanted to ask and make sure it sounds right. I will be running two 18's dual 2 ohm Bl's with the old school directed 2400D. I plan on building seperate boxes for each 18" so its easier to install //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Ok well anyways im going to put these in the back seat of a trunk car and wall it off hopefully. The max dimensions I have are 50 wide 30 tall and 24 deep. The single box I made was 30 wide 25 high and 24 deep, with the port on the side, but I planned on just flipping the box so the port was either on the top or bottom, cuz I couldnt flip the box when I was making it. The port is 4.75 wide 23.5 high and 18.5 deep. This says it should give me a box that is 7 cubic feet tuned to 35 hz with around 111 inches of port area. If that sounds correct then thats what I will make. Another question is instead of it having the second part of the port which makes it an L shaped port is it ok if that part isnt there and its just a straight slot? Sorry this is so long but I'm just looking for any help.

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[46panel 10+ year member]

This is what I drew up just in paint it. The one on the right is how the picture looked that the program desgined. The one on left is just flipped around how I would want it. Just want to make sure that would work with the port not being an L shaped and to make sure its tuned right around 34-35ish

 

[Rashaddd 5,000+ posts]

Build a single chambered box for that...don't split it into two boxes just because it'll 'be easier to install' only reason to do that is if it literally wont fit into your car unless you split it, which is what I had to do

Idk what you meant by not doign the L part of the port but you can't just skip parts of the box, the L part of the port would mean your box isn't deep enough to have a straight run to the back and make the port long enough, so you have to wrap it around some in order to get enough length

 

[46panel 10+ year member]

That is what I meant, when I said the part that makes it an L. I didn't know if the bend was just to make the port longer or if you actually needed that part for any other reason. Could you or someone else help with a design that is a single chamber. With max dimensions of 50 wide 30 high and 24 deep tuned anywhere between 33 and 35. Or just tell me if the design I made up there looks right and then I can just mess with it to try and get what I need. Thank you.

 

[Bassphreak 10+ year member]

You've never built a box so I wouldn't even think of building a wall (and the way you're going about it is way off).Build a few boxes,do your homework and then think about doing a wall.

Walls are heavy,you're going to likely need to beef up your suspension.

That L in the port you need that if the plan calls for it if you were to build a box from a box plan that required the L shaped port wall and built it without that extra piece of MDF to make it an L you would **** with the tuning of the box.

 

[46panel 10+ year member]

Well I'm trying to do my homeowork and look around and ask questions. The design that I got I made it so I didnt need the part that made it an L since the box is 24" deep and the port was only 18.5 so I dont need to bend it. I'm mainly just asking if the box I made up above looks like it would work, I guess i will just hope for the best, if anyone can help out I'd appreciate it.

 

[46panel 10+ year member]

Sorry for the noob questions...but my design shows it has the correct amount of volume inside and enough port area and tuned correctly but the port is on the left side. I'm just wondering if I build it that way and then just flip the box so the port is on the bottom after its all done would that change the tuning? I dont see why it would, but I just want to make sure.

 

[lvjeffro 10+ year member]

http://www.reaudio.com/speaker_box/LPort_Box_Calc.html

as long as the port volume and cubic feet of the box remain the same, the tuning will not change, but depending on your vehicles accoustics it might hinder some performance on where you face the subs and the port...