can someone port/tune this box for me?

[aaron7114 10+ year member]

Alright Im rebuilding the wall in my car because it turned out horrible. I did have a new box designed but I decided to make it a little bit bigger so I need it retuned.

Here is the box I was gonna use, which I believe is tuned to 50 hz for comp:



(Doesn't include extra 3/4" baffle on front)

Then I was gonna plug the port so it was this size for daily which cut the tuning down to 35 hz I believe:



Doesn't include extra 3/4" baffle on front)

However like I said I decided to make the box a little bit bigger.

My external dimensions for the new box are: 40 wide x 21 tall x 17 deep + 3/4" extra baffle on front.

I'm willing to lower the SPL tuning a tad and raise the daily tuning a tad if it makes it easier to accomplish. A tuning for daily of 36 or 37 would be ok.

Port with for the SPL tuning should be 5" I believe to go by 1:4 ratio with the height.

This will be for two 15" L5s (later on for L7s) powered by a Kicker KX2500.

Thanks.

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[blackbonnie 5,000+ posts]

so what is your question though? i guess i didnt catch it

 

[aaron7114 10+ year member]

since I changed the box size that changed my tuning so I need to figure up what size port and port length and everything needs to be.

The tuning, if all the calculations and everything were correct on the boxes above the tuning for the SPL port was 50 hz, then with the port plug it was 35. But if it makes it a little easier/better to do I would be willing to drop the SPL tuning a little and raise the daily tuning a little. For daily 36 or 37 hz would be fine.

 

[aaron7114 10+ year member]

bump.....still needing some help

 

[shortyg83 10+ year member]

Well with 2 subs sharing the port if you do a 4 inch wide port its going to be aprox tuned to 40hz i believe.

 

[aaron7114 10+ year member]

Well with 2 subs sharing the port if you do a 4 inch wide port its going to be aprox tuned to 40hz i believe.

I'm wanting to do a 5" wide port for SPL.

Then want to make a plug to make the port smaller to lower the tuning for daily.

 

[rpfuror 10+ year member]

SPL:

Slot Vent Width: 5.00 inches

Slot Vent Lenght: 12.00 inches

Net Volume: 5.23 cu/ft

Tuning Freq: 49.94 Hz

Port Area: 97.50 sq/in

Daily:

Sq Vent Width: 3.00 inches

Sq Vent Height: 17.00 inches

Sq Vent Length: 11.00 inches

Net Volume: 5.23 cu/ft

Tuning Freq: 37.25 Hz

Port Area: 51.00 sq/in

 

[rpfuror 10+ year member]

BTW, Thats not a big enough box IMO. My best results with a set of 12" l7 in 3.25 cu/ft each. So, from my expeeience that's not enough for even a set of 12's

 

[aaron7114 10+ year member]

BTW, Thats not a big enough box IMO. My best results with a set of 12" l7 in 3.25 cu/ft each. So, from my expeeience that's not enough for even a set of 12's

My box in my trunk was about 6.5 cubes and it did a 153.6 on the audiocontrol. Then I built the wall which was about 11 cubes and it did a 149.7 on the audiocontrol.

I know the general rule is comp=small box...daily=big box....so im just tryin to get in between the two.

Would you still recommend goin bigger?

 

[rpfuror 10+ year member]

Really depends, I have only tested the l712's (in many boxes) for daily, that's how I came up with the numbers.

I would at least shoot for ~4 cu/ft per driver. So 11 would have been to big.

 

[rpfuror 10+ year member]

Per you PM, here is a multi port design for your drivers.

SPL

Net Volume: 8.25 cu/ft

Tuning Freq: 50.00 Hz

Port Area: 132.50 sq/in

Daily

Net Volume: 8.00 cu/ft

Tuning Freq: 36.00 Hz

Port Area: 82.25 sq/in

 

[aaron7114 10+ year member]

That looks awesome rpfuror! You need to teach me how to make sketchups look that good. What program do you use to make your calculations?

Only thing I'm really worried about is havin too much port area on the SPL setup.

Edit: Also what is the lengths on the port?

 

[rpfuror 10+ year member]

8 & 13"