Im not so sure how to tune a ported box

[Nugg32 10+ year member]

i'm trying to make myself a box and i have two jl audio 12w6. On Jls website it gives me the measurements on how to make the box and it says to tune at 32.2 Hz. if i make the box with the exact measurements what else would i have to do to make it "tuned"

http://www.jlaudio.com/12w6v2-d4-car-audio-w6v2-subwoofer-drivers-92121

Go to specification tab and at the bottom it says ported enclosure specifications and it will tell you everything

Click to read more...

 

[butterMilk 10+ year member]

Build it with the exact measurements, and exact port length. JL has taken all the guess work out of it.

 

[Bettr n' Revrse 5,000+ posts]

Tuning is based on port length, width, box volume, ext... So if you build it the right exact specs it should be fine

 

[bkim921 10+ year member]

somewhat on topic.. what happens if your box is somewhat smaller than the recommended minimum.. my box is about .20 cubic feet smaller..

 

[BoomBoxStereo 10+ year member]

somewhat on topic.. what happens if your box is somewhat smaller than the recommended minimum.. my box is about .20 cubic feet smaller..

tuning will be higher, but not by much

 

[americannight 10+ year member]

The only thing that raises an eyebrow with the JL design is the width of the slot port at only 1.5". I would be concerned about port noise. You can widen that slot to 2" but the slot will need to be longer. There are calculators online you can use to calculate the new length. If this is in the trunk, though, firing back, you may never perceive the port noise.

 

[americannight 10+ year member]

Also regarding your question about two woofers, just make one box with a divider in the middle (a two chambered box). Each chamber gets its own port and sized as in the JL design.

 

[Nugg32 10+ year member]

Also regarding your question about two woofers, just make one box with a divider in the middle (a two chambered box). Each chamber gets its own port and sized as in the JL design.

could i just put the ports on top and use the height as my width? cause with the 2 subs it would make my box over 50 inch wide if i made it with the ports in the middle or on the sides and it wont fit like that, but if i put my ports on top and use my width as my hight my box will be 28 inch wide and a height of only 25.75 inch and that will fit

so if i build the box the exact why they want it my box will be 51.5 inches wide and a height of 14 inches and that will NOT fit in my car

if i build my box with ports on top it will be 28inches wide eith a height of 25.75 inches and that will fit soo would that work or not?

 

[americannight 10+ year member]

There's a good sticky thread on this. Read this:

http://www.caraudio.com/forums/enclosure-design-construction-help/215849-simple-edu-how-design-ported-box.html

Long answer: What you are designing to is the net internal volume of the box. Sure, you can adjust the length/width/height as needed so it fits in your particular vehicle. In the case of this design, you want a box that is 1.5 cu ft NET (so that is after driver displacement which JL spec sheet says is .090 cu ft for this speaker, and displacement of the port and any bracing that you put in the box). This sticky will show you how to calculate the volume. Main considerations are 1) will it fit in the vehicle 2) is one of the sides large enough to fit the woofers 3) where to place the ports.

Short answer: yes, you can put your slot port on top. It may cost you a little bit in spl but not much. So long as the slot has the same dimensions as the JL design, it will have the same 32.2Hz tuning. Keep in mind, port noise is even more noticeable if you have the port firing up towards your rear deck. So if you decide to take my advice and make the slot 2" x 12.5" instead then it should be 38.2" long for the same tuning. You'll get less port noise that way.

 

[Nugg32 10+ year member]

There's a good sticky thread on this. Read this:
http://www.caraudio.com/forums/enclosure-design-construction-help/215849-simple-edu-how-design-ported-box.html

Long answer: What you are designing to is the net internal volume of the box. Sure, you can adjust the length/width/height as needed so it fits in your particular vehicle. In the case of this design, you want a box that is 1.5 cu ft NET (so that is after driver displacement which JL spec sheet says is .090 cu ft for this speaker, and displacement of the port and any bracing that you put in the box). This sticky will show you how to calculate the volume. Main considerations are 1) will it fit in the vehicle 2) is one of the sides large enough to fit the woofers 3) where to place the ports.

Short answer: yes, you can put your slot port on top. It may cost you a little bit in spl but not much. So long as the slot has the same dimensions as the JL design, it will have the same 32.2Hz tuning. Keep in mind, port noise is even more noticeable if you have the port firing up towards your rear deck. So if you decide to take my advice and make the slot 2" x 12.5" instead then it should be 38.2" long for the same tuning. You'll get less port noise that way.

are you talking about the Internal Slot Port Depth being 38.2" long?

so if i have this right and i build it the way i was asking, it should be like this?

Port Width: 2inch

Port Height :12.5inchs

Port Depth : 38.2 inch

 

[Bettr n' Revrse 5,000+ posts]

are you talking about the Internal Slot Port Depth being 38.2" long?
so if i have this right and i build it the way i was asking, it should be like this?

Port Width: 2inch

Port Height :12.5inchs

Port Depth : 38.2 inch

There are a lot members that can design you a custom box if you want t go that route...

 

[Dtrom 10+ year member]

Plenty of guys on here can build/design your box