Is my Sub Box messed up

[roudabout6]

About a month ago I bought a custom box of craigslist from my area for $85. I looked over it all good no cracks seems missing. Looked like a nice well build box. Dimensions of it where 36 x 14 x 21.5in with a port 6 x 13 and length of 25.75in. Now realizes that my box was tuned much higher than I wanted. I got some mdf and wood glue to decrease the port width. Now my problem is I only decrease the width of the first 14.75in of the port, or to the 90 degree turn. So I am worried that I have messed up my box and will have to buy a new one.

Here are the blueprints for the modified box

Click to read more...

 

[mazdakid 5,000+ posts]

You would have to reduce the whole length of the port.

Did you buy a prefab or custom box from Craigslist?

 

[roudabout6]

You would have to reduce the whole length of the port.Did you buy a prefab or custom box from Craigslist?

Custom box from craiglist and I did not reduce the whole length of the port just the first length until the turn. Like shown in Google Sketch up

 

[Jeffdachef 5,000+ posts]

add the same to the L section of the port, make it even all around.

 

[roudabout6]

add the same to the L section of the port, make it even all around.

So add width where the red is not where the blue is?

View attachment 26551304

 

[Jeffdachef 5,000+ posts]

add to the red. How much thickness are you adding? You do know the port wall is different from the port length right? and your height measurements dont add up. in a slot port you have thickness of mdf which is .75 inches. You stated 14 and 13 for port height. They need to be 1.5 which is the thickness of top and bottom mdf

to measure port length, you are actually going down the center line of the port. Like the red line in this pic

 

[roudabout6]

add to the red. How much thickness are you adding? You do know the port wall is different from the port length right? and your height measurements dont add up. in a slot port you have thickness of mdf which is .75 inches. You stated 14 and 13 for port height. They need to be 1.5 away from each other.

Oh that is my bad the height is 14.5 not 14. So add to just the red. But how much?

 

[roudabout6]

I did the measurements for port length down the red line like shown

 

[Jeffdachef 5,000+ posts]

Oh that is my bad the height is 14.5 not 14. So add to just the red. But how much?

how much width did you add to the first port length?

what subs are going in this?

 

[roudabout6]

1 1/2 to each side. So the port is now 3in wide. I am realizing that that I added to much and I have American bass XFL 12s 2 of them

 

[Jeffdachef 5,000+ posts]

yeah you took off a little bit too much.

your enclosure is now 34.5 in width not 36 anymore. You have to subtract around 0.2 cubic feet away from net airspace from the added thickness to the ports inside.

If you add 3 inches to the 2nd port then you would be even all around tuned to 29-30hz around 3.8 cubic feet. However, you'll have very little port area, you might or might not get some port noise and lose some efficiency. it'll hit lower but not louder.

 

[roudabout6]

yeah you took off a little bit too much.
your enclosure is now 34.5 in width not 36 anymore. You have to subtract around 0.2 cubic feet away from net airspace from the added thickness to the ports inside.

If you add 3 inches to the 2nd port then you would be even all around tuned to 29-30hz around 3.8 cubic feet. However, you'll have very little port area, you might or might not get some port noise and lose some efficiency. it'll hit lower but not louder.

I am looking for it to hit as loud as it can. I do care about lows but prefer it to be louder. So how would I go about doing that. Also thank you for the fast replys and being so helpful.

 

[Jeffdachef 5,000+ posts]

you might just want to build a new box, if you have woodworking skills, the design i posted earlier is 4.2 cubic feet tuned to 34hz with 16 cubic feet of port area which is fine for those xfls.

 

[roudabout6]

I was really not wanting to build a new box is there anyway to save this one?

 

[Jeffdachef 5,000+ posts]

I was really not wanting to build a new box is there anyway to save this one?

it'll require a lot of chopping up and drastic modifications.