Hey guys, i'm going to build my first enclosure in the next few weeks sometime and need some opinions. The box is for 3 Oz Matrix 250L D6, i used winisd and it says the optimum box is 6.1 cu ft tuned to 30.5hz, The box I have planned is 38" x 18.5" x 18.5" which works out to a net internal volume of around 5.9 cu ft.

I want to tune it to 31hz and my options are one long slot port running the length of the box 36.5" x 1" and 4" long, or 2 shorter slots on either side of the box 17" x 1" and 10" long.

Making the box with one port would be easier, but i'm not sure if there are adavantages or disadvantages to either.

So should I use one port or two and is there anything else I am not taking into consideration?

This is for a daily bumping set up, I want good sq but I need it to get loud as well.

 

From what I've read the general rule of thumb is not to go over a 9:1 ratio with width and height or else you get a lot of port noise.

If my math's right, the single port will tune your box to about 43 Hz and the double one to about 34 Hz. The lower you tune, the longer the port has to be if you keep the same cross section area.

As for one port or two, I can't help you there. I've only dealt with one myself.

 

that doesn't sound good, anyone have a good slot port calculater? I used winisd's square port calculater, i guess it doesn't work the same.

 

http://www.jlaudio.com/tutorials/ports/index.html

Don't have a calculator for it, but I use the equation on this page here. Takes a while longer to figure out, but it works.

 

So, let's say you have a 3" x 3" port and compare it to an 20" x 2" port ... Which one will give you more port noise

You're supposed to keep it as symmetrical as possible to keep tuning ACCURATE ...

 

My home theatre sub is about 3.2 cu foot, tuned to about 24.5hz give or take with 1 port 4"ID*14.75" if I used 2 of the same any idea of what my tunning would be ?

 

math was never my strong point, so if any one could tell me what size port would tune a 6 cu ft box to 31hz that would be much appreciated.

 

2x 4" round ports,9" long
or
12"x2.5"x23"long slot port

 

What about port displacement ?