Two ports as good as one?

[Bob Tzimenatos]

I'm no noob to this lifestyle, but I have been out of the game for a long while- kids and work took care of my expendable income.

I am building a box for a Kicker S12L5. Got the box parameters from Kicker. Calls for a rectangular port 2.5x13.25x16.5. My question is this: can I use two ports 1.25x13.25x16.5 or will it affect the tuning ( with one rec port the tuning is 33hz.). Thanks!

[deathcards]

http://www.stevemeadedesigns.com/board/topic/38791-torres-box-tuning-calculator-updated-818/

this can help design a box closer to what you want to tune to fun to play with once you understand it

[firebirdude]

delete

[TaylorFade]

First... you want to keep the height to width ratio of your ports less than 9:1. So there's that.

Second... in general... one larger port is more efficient than two smaller ones because there is more surface area and less lamina.

Is it a design challenge? Why do you want to split them?

[Triticum Agricolam]

In addition to the points that TaylorFade brought up, when changing from one port to two the two ports with the same total port area, the two will need to be a little longer to have the same tuning as a single larger port. The proper way to do it is to calculate a new port length using half the box volume for each port. For example if you have a box with 2 cubic feet of net volme and with one port with 32 sq in of port area tuned to 30 Hz, if you wanted to change to two ports you would calculate how long a port you would need for 1 cubic feet of net volume and 16 sq in or port area tuned to 30 Hz.

[Bob Tzimenatos]

I wanted two slot ports to balance out the look of the box, rather than having one port on the face of the box.

I am building this box, with the S12L5, with the intention of swapping it out for a HDS312. I am building a removable panel that the sub will be mounted to, so I don't have to build a new top for it. I am building this box now, I'll post a build thread.

I am saving for a SQ 1200.2 and a HDS312.

[Joe X]

I would even increase a bit total port area,

[Bob Tzimenatos]

Here's the specs for my box. I have built this box since I started this thread. Outside dims: 32x14.5x14.5"= 3.09 ft3. Port:2.5x13.25x16.5"= .49ft3 net box volume= 2.51ft3. This is good according to the Kicker specs, and good for the HDS312 - if I increase port size and length. This will be relatively easy to do, since I made the top removable.

Thanks for the help, I'll inform you of the results tomorrow.

[Triticum Agricolam]

Got any pics?