4th Order help, or confirmation. Want to get building next week.

[scooter99]

BOOOM HEAD JUST ESPLODED!!!!

[scooter99]

Think I bought a couple more inches guys. Long story, but I'm going to be able to add 2 more inches of width to the ported and sealed section. So I'm at 1.77^3 sealed, and 4.17^3 ported before port displacement. But that includes sub displacement and an extra baffle.

[scooter99]

Ok I've made some headway here. After some brain rest and a good night sleep I re looked at that chart.

With the new found space, I'm sitting at 4.17cubes after displacement but before port displacement. So based on the chart, if I'm looking at 2 6" round ports, that's 56.54^2 of port area as you can see below.

So following the directions, which I didn't clip out sorry. If I take that area, and divide it by the diameter of the port, in this case 6", I get the following: 56.54 / 6 = 9.42"

So that gives me a 6" wide by 9.42" tall port.

I'm going with about a 1:2 ratio. So at the bottom of that page there's a link for 6" ports. For length. If I look at the enclosure space, I'm between the 4.00 and 4.25 on the chart. Left hand side of the chart. So I figure I'm about half between that. If I go to the target tuning, 44-50, it gives me all my lengths. SO I can make a few different ports to interchange them and decide what I like best.

Each inch of port, approximately, equals 2hz. So a 1/2" difference is 1hz.

So I'm looking at a 6" x 9.42" x 9.5" port to get me in the 48-49hz range. Puts me at really close to a final ported cube of 4.00^3.

So final numbers should be around:

4.00^3 ported

1.75^3 sealed

port at 6 x 9.42 x 9.5 tuned to 49ish hz.

What do you guys think about that?

[CleanSierra]

I'm digging that last number crunch of yours. I think you'll be happy anywhere from 46-50 Hz and I like that you will make it easy to be adjusted so you can figure out which you like best.

[CleanSierra]

BTW, I get the same as you, 1/2" increments in length equal 1 Hz.

[scooter99]

Thanks. Feel like i understood that after walking away from it for a bit.

I'm going to do some testing on the sub, with CJVue, next week to get the exact T/S on it, since it's not a bone stock XL. I went off the sites parameters which to my understanding is based off of a stock sub. SO I want to make sure I'm on the right track.

If all that is good. I WILL be building a 4th!! Thanks for the help guys! My next update will most likely be in my build log next week when I get to building.

[vetkilr01]

Tune the ported to the same tuning as your sealed section... I am gonna add some poly fill to lower my sealed tuning down some more. If you like radio style music then around 50 hz is good...if you go decaf sub 30's or low 30 hz music then tune to 42 to 45 hz.

[scooter99]

That's what we're going to be after. I'm going to do some testing on the sub next week, before I build anything, and then we'll see what's what. Then I'll start building a test enclosure or something like it, and figure out the tuning etc. Thanks for the input. I think for the most part I'm going to try and stay around the 45hz range. I'm going to be using it as a daily driver, but I want to be able to demo the lows too if I have that situation.

I'll know more next week.