building first box

[anti*commander]

im prolly going to build my first box, im using 2 12 inch subwoofers that require 2.4 cubic feet and tuned to 40 hz for a ported box. my question's are...

1. how do i calculate the length/heigth/width of the port to know its tuned to 40 hz.

2. would it be better to have each sub in its own chamber, or both in one big box that is 4.8 cubic feet, if its the big box, then do i tune the port to 80 hz?

3. (off topic) where is a constant power source, one that is on when key is in on, and in start (does not cut off like the headunit power)?

Thanks, and sorry, im new to custom boxes.

 

[DOZIER]

As for the enclosure design. Go to the RE Audio website, and there is a link to a box calculator in there in the bottom left hand corner of the main page. Put your specs in and it should spit out some dimensions you can work with. As for the subwoofer space. You mean each subwoofer requires 2.4 cu.ft. which comes to 4.8 cu.ft. total between them. The port can still remain at 40hz. It will show you how to do the port on the calculator. They can both remain in the same open space. No chambers. As for your constant power wire...I am not sure. I personally would run a new wire with a switch if you want it to stay on when you turn the key to on. check the cigarette lighter. It might stay on when the key is turned.

 

[sjr033]

1. Here is a link to JL Audio's web site that gives you tips on build you own box. Link how to figure the port size, bracing the box, etc.
http://mobile.jlaudio.com/support_pages.php?page_id=141
2. I would build 2 seperate chambers. You can do 1 big chamber. Either way you still tune to 40hz.
3. Please clearify. You ask for one that is on when key is on and in start. That is not a constant power IMO. What are you trying to hook up to constant power?

 

[anti*commander]

when i say constant power source i mean one that is off when the key is not in the ignition, on when in "on" and in "start" this is being used for a battery solenoid.

 

[Aero540T]

Just curious, but is there any reason you want to tune to 40hz? That's pretty high of a tune, to me. My first box was tuned to 30hz, and my second to 34hz, and I preferred the first one a bit more. I couldn't see tuning much higher than that, you lose a lot of low-end

 

[Aero540T]

1. Here is a link to JL Audio's web site that gives you tips on build you own box. Link how to figure the port size, bracing the box, etc.
http://mobile.jlaudio.com/support_pages.php?page_id=141
2. I would build 2 seperate chambers. You can do 1 big chamber. Either way you still tune to 40hz.
3. Please clearify. You ask for one that is on when key is on and in start. That is not a constant power IMO. What are you trying to hook up to constant power?

off topic...dude do you go to WMU or just live in the Kzoo? I'm at WMU right now

 

[anti*commander]

im just going by what the sub spec's were, it says 40 so, went with 40

 

[sjr033]

off topic...dude do you go to WMU or just live in the Kzoo? I'm at WMU right now

I just live in Kalamazoo, well Portage to be exact.

Anti, as for you power lead you are looking for. There are many fused circuits that meet your needs, the hu circuit, power window, etc or even your hu remote turn on lead. Just tap in and use a relay if you need more power. Also a fuse is never a bad idea.

 

[toypaseo]

My 2¢...

I would build a separate chamber box. In a few, I have seen subs fighting each other in single chamber boxes.