Box design help. driving myself nuts

[dreuosborn]

OK here is what I came up with:

Now for the bad news. I had to make some design compromises to make this fit in your space. First off I wish the port was a lot bigger. Those drivers have ridiculous excursion and the need an equally ridiculous amount of port. I couldn't do that or there wouldn't be any room left. So if you put enough power to this I can't promise you won't get port noise. I think it will take a LOT before that will happen though. The second design compromise is you only have 1.8 cubes per driver, not the 2.5 you wanted, but as you can see there just isn't room.

man that is a great looking box. if you don't mind can I ask how many inches of port area that box does have. Where the tuning ended up? also Is there a cut sheet? cause some cuts will be difficult to work out like the interior port walls.

[Triticum Agricolam]

man that is a great looking box. if you don't mind can I ask how many inches of port area that box does have. Where the tuning ended up? also Is there a cut sheet? cause some cuts will be difficult to work out like the interior port walls.

Thanks for the compliment! I forgot to say that the box is tuned to just over 30 Hz. It has 62 sq in. of port area. I can make a cut sheet I just haven't gotten to it yet. To do the flared port mouth you will have to kerf bend the outer baffle/port piece. The flare is important to minimizing port noise.

Also why I am at it I'm going to get on my soapbox for a bit. I said earlier this design has some compromises and is not optimal. That doesn't mean it still won't perform very well. I think too often folks let the quest for perfection be the enemy of the good. This makes them think that anything that is less than perfect is garbage and isn't worth doing at all. I disagree. Yeah this design isn't perfect but I still think it will rock your face off....twice.

[dreuosborn]

man that is a great looking box. if you don't mind can I ask how many inches of port area that box does have. Where the tuning ended up? also Is there a cut sheet? cause some cuts will be difficult to work out like the interior port walls.

Thanks for the compliment! I forgot to say that the box is tuned to just over 30 Hz. It has 62 sq in. of port area. I can make a cut sheet I just haven't gotten to it yet. To do the flared port mouth you will have to kerf bend the outer baffle/port piece. The flare is important to minimizing port noise.

Also why I am at it I'm going to get on my soapbox for a bit. I said earlier this design has some compromises and is not optimal. That doesn't mean it still won't perform very well. I think too often folks let the quest for perfection be the enemy of the good. This makes them think that anything that is less than perfect is garbage and isn't worth doing at all. I disagree. Yeah this design isn't perfect but I still think it will rock your face off....twice.

Im down for a little kerfing action, and I certainly trust in your designing ability and skill level. This build will be meticulously built, I can feel the excitement building already, so exited can't thank you enough. Just out of curiosity, I built a box that had only two pieces of wood to the port assembly, port in the middle. They were two straight pieces of wood that went a certain distance back (cant remember) and then just ended and that was the port. that box had pretty ridiculous port noise(cant attribute it completely to the design as it was my first build) my question is do the port walls in this box (appears to be 6 pieces total) serve the purpose of reducing port noise or is it to get the tuning where it needed to be? trying to learn all I can about this art.

[Triticum Agricolam]

Yeah the reason the port curves around the back of the box is to get it tuned properly. The reason your other box had such a short port was probably because it didn't have much port area (which would be a recipe for port noise) and was probably tuned higher. There are three things that affect how long a port needs to be, what it is tuned at (lower tuning=longer port), how much port area it has (more area=longer port), and the volume of the box (smaller volume=longer port). This is why it gets really difficult to fit a large, low tuned port into a small box. Pretty soon your port takes up more volume than the driver chamber does.

[dreuosborn]

30 hrz is gonna be great, its perfect. how wide is the port opening on this one 4 incher or so? 3.5?

[Triticum Agricolam]

Yeah its 4". I'll post some more screenshots with all the dimensions as soon as I get a chance.

[dreuosborn]

No rush, I appreciate it. Do you do any building yourself up there for customers? (saw your facebook page but wasn't sure)

We are both in Washington, and I have friends that want more than I can provide for them. they are very generous.

[Triticum Agricolam]

No rush, I appreciate it. Do you do any building yourself up there for customers? (saw your facebook page but wasn't sure)

We are both in Washington, and I have friends that want more than I can provide for them. they are very generous.

I'll try to get the cut sheet and stuff up later today.

I absolutely do build for folks, if you can send anyone my way I would greatly appreciate it!

[bassman619]

With that box design and cubic feet of space you can push two rockford t2 15s optimally..fiberglassing the inside of the box will make it stronger but also make it heavier and harder to get out of the car. You can always use threaded bars for bracing with some nuts and lock washers t9 hold them in place..that box looks good. Btw..but we all know you wont be able to use the subs you want with it. I would say go with 12s because then you can work with less space..not always about the biggest sub..its about what works best with the car. 15s and up are really meant for suvs..unless you just do 1 15. I get what u want to do and definitely respect it but id say if you are set on running subbs like that you might want to sell your car and get an suv or wagon thats the only way youll have the room you need for that..as for your current box you can always add a little more port length and it will drop your tuning lower..good luck ..post pics. Wed like to see how it comes out

[Triticum Agricolam]

Ok here is the cutsheet: https://dl.dropboxusercontent.com/u/1642665/Cutting%20Diagram%20for%20Dual%20Ported%20FI%20Q%2012.pdf

And here is the SketchUp file: https://dl.dropboxusercontent.com/u/1642665/Dual%20Ported%20FI%20Q%2012.skp

I REALLY recommend you look at the design in SketchUp and pull your dimensions from there. It's a fairly complex design and I'd hate for the build to not go well. Also I didn't bother putting any of the 45's or other braces in the cutsheet.