View Full Version : Help calculating port length and size?

12-16-2009, 07:46 PM
I have 2 Kicker CVR 10's in a sealed box right now. The box manufacturer said it was 0.85ft3 for each sub. In actuallity, the box is one big 1.7ft3 sealed box. I have a rf amp giving each sub between 350-375 watts. I am thinking about porting the box. Should I use one port for the whole box, or 2 for each side/sub? I would like to tune it to 30hz and run either 2" or 4" round ports. I played around with some formulas, and came up with the numbers below:

1-2" port=4.1" length
2-2" ports=9.6" length
1-4" port=8.14" length
2-4" ports=19.214" length

Would 2" or 4" port/ports sound or perform better? Would any of these set-ups be louder or sound better than the sealed box I have now? I would rather have SQ over SPL.

12-16-2009, 07:50 PM
I'd go with one 4" port

Two 2" ports isn't much port area and two 4" is a lot (for your volume)

12-16-2009, 11:29 PM
Ok, forgive me! I am a total newb on ported enclosures! I was thinking either 1 4" in the middle of the box or 2 2" over each sub's "box". I think I might have to go with 2 2" ports though because the logical port location I can see isnt very wide. I'll look around the box and see if I can find a spot for 1 4" port.

12-17-2009, 01:18 PM
1.7 For two 10” sub ported is going to be close (subtract the displacement of both subs and the total port volume)
Your going to loose .3 - .5 in total box volume
The smaller the box = the longer the port length (will it fit in your box)
A 4” port would have to be over 15” long
Your tuning frequency is to low for that small of an enclosure

You need more box

12-17-2009, 01:24 PM
i know for 1.75 cubes and 35 Hz you need around 17" for a 4" aero...