How to check the airspace and port tune on enclosure

Not sure this helps but I have the spec sheet for the 10 in type r in my hands and it reads:
Optimal vented box-0.6-1.25
external box dimension-12.5"x14.5"x17.25"
Vent area-11"x1
Vent length- 22 in

 

I need two more pieces of information.
First how long is the port?
Second, is the box divided (in other words is this two boxes in one)?

Please be exact on the Port length (within an inch) and I need to know if its divided so that I can determine the port tuning

 

Let see what we have, the usable (not including port area) interior space is (everything is approx) around 3.3 cu ft, thats good.

Port tuning is around 30 Hz, why? A tuning around 35 to 36 would have done a better job. But it is acceptable. And its not our problem.

Our problem is that the port is in the wrong place, it needs to be on the baffle board with the speaker. In other words, the speaker and the port need to face the SAME direction.

Facing the speaker and the port the same way will fix your problem, also face the speaker and port to the rear of the vehicle

 

The box in your drawing would have been OK if they had the ports in the right place.

As far as the distance between the hatch and the box, its OK but can we get one more inch to be on the safe side?

Lets readjust our tuning to 36 Hz. You'll be much happier, more output.

Are your woofers 10s or 12s? I'm gonna use you dimensions with a few minor adjustments.

I will get back to you soon, I'm a teacher and I have to go back to work tomorrow.

 

OK, lets go with a box that has the outside dimensions of 45-inches long by 12-inches tall by 14-inches deep.

Now I want a little more port size than what you have in your drawing. Lets go with a set up just like you have. But now our ports will be 10.5 inches tall by 1-inch wide. The port needs to be 12-inches long.

Top and Bottom board 45 x 13-1/4
Back board 45 x 10-1/2
Sides (2) 12-1/2 x 10-1/2
Port boards (2) 11-1/4 x 10-1/2 (if the port board is between 11 x 10-1/2 and 11-1/2 x 10-1/2 we are OK)

Baffle board is cut only after the rest of the parts are put together

Baffle board 45 x 12

Follow the directions here, just remember that you have a bigger box and you have a 1-inch wide port on each end.
http://www.caraudiotalk.com/audio-forum/showthread.php?t=7031

JUST LIKE YOUR Sketches, only the dimensions have changed slightly

 

This sketch is not to scale, this is a top view

 

This box will work, There are so many "experts" out there, its scary. When someone says they "tune low to make it hit low", run, they have no clue. NONE What-so-ever.

Anyway build this one, you'll like it.

 

No we do not need to turn the ports in. They will be long enough just like they are.

The baffle board is the board that the speakers mount to, and in most cases the ports are located on the baffle board. Also, its cut last so that its attached to the outside parts of the box. This adds to the strength of the box.

Yes please add the braces. Yes the drywall screws are good, their main purpose of the screws is to hold the boards together until the glue drys. As far as the glue, I used Elmers wood glue. But any good glue will work.

Speaking of braces, lets add a couple to that box

Atleast two, three would be good. We dont want the large back board or the baffle to flex

Braces 10-1/2 x 4 or 10-1/2 x 3
Cut cut two, three, or four (look back at my box building thread and look for the braces)

An EXAMPLE

 

Yes definately put them in.

I really think you'll be suprised, that box will perform well. Definately build it and let me know what you think

 

The side the ports are on (as long as they exit into the listening area) is not highly critical. How many home subwoofers have the port on the bottom or the back side of the enclosure? Plenty. I agree, the side with the woofer is optimum, but not critical.

 

But I'm not talking about a home subwoofer, I'm talking about a car. Much less volume in the car. Port Location IS critical in a car.

 

I tend to actually agree with this ...

But the fact of the matter is that by utilzing reflective surfaces in a vehicle, corner loading and the likes. you can and will achive more boom for your buck... Not that it is musically accurate by any means...but it sure can make or break how hard it hits compared to your buddies car....


It all aint meant for musical accuracy anymore........lol!

 

build Rangers box! it will slam. I promise you