First ported box... Need a little help

[JeepSound 10+ year member]

I tried using Ngsm13's writeup, but I don't think I did it quite right. I think I may have skipped a few things. I ended up only having an inch between the back wall, and the end of my port... is that OK, or did I do something wrong? Basically, my port turned out to be 2"(W)x13"(H)x16.5"(D). My box dimensions are 14.25(H)X21(W)x17.5"(D)

I'm kind of leaning towards the idea that I did something wrong.

And I don't know if I need to give you guys any other information before you can determine if I did it wrong or not, so any help will be appreciated.

Or is there someone that can design me a box if I give them the info? I'd like to get it right the first time.

Click to read more...

 

[terra 5,000+ posts]

ya many people can design u a box on here

 

[Trixter 10+ year member]

since your only 1" off can't you shorten it an inch and add an inch sidways?

 

[JeepSound 10+ year member]

since your only 1" off can't you shorten it an inch and add an inch sidways?

Well I guess I could, I just wasn't sure if there was a certain amount that needed to be between the back wall and the port...?

 

[punch 10+ year member]

I tried using Ngsm13's writeup, but I don't think I did it quite right. I think I may have skipped a few things. I ended up only having an inch between the back wall, and the end of my port... is that OK, or did I do something wrong? Basically, my port turned out to be 2"(W)x13"(H)x16.5"(D). My box dimensions are 14.25(H)X21(W)x17.5"(D)I'm kind of leaning towards the idea that I did something wrong.

And I don't know if I need to give you guys any other information before you can determine if I did it wrong or not, so any help will be appreciated.

Or is there someone that can design me a box if I give them the info? I'd like to get it right the first time.

yes there is a minimum from the end of the port ( I don't know what that is though.), just make it L shaped.

 

[MemphisSoul4U 10+ year member]

Well I guess I could, I just wasn't sure if there was a certain amount that needed to be between the back wall and the port...?

Typically the port width (or diameter) away from the back of the box...

 

[JeepSound 10+ year member]

I decided to tune it to 37hz which makes my port 14"s long. That'll leave 3.5"s for it. Should be enough... I hope.

Since it's my first prted box, I don't excpect it to be perfect, but I do hope it turns out good enough to be louder than my sealed.

 

[Trixter 10+ year member]

all you need to remember is that is needs to maintain it's squareness and you always measure the length down the center. if your port is 2" wide, then you need to end you first port board 2" from the back of the box. if it needs to turn, then you need to have you second port board 2" from the back of the box.

Also, not mentioned yet in this thread, is the end correction factor. a correction factor is needed if the port shares a common wall with the box. the correction factor is simply adding 1/2 the port's width to it's length.

this is from JL's website...

"The effective length of the port is found by adding an end correction factor. An end correction factor is necesary because more often than not, one wall of the port is also one wall of the enclosure and this wall extends beyond the end of the port thus effectively adding length to the port (remember, the driver can't "see" the length of the port, it can only go by what it "feels" is going on)."

if you didn't add the correction factor, don't worry too much about it. in your case adding 1" to the port's length will probably only make about 1hz difference. the wider the port (and the more port area) the bigger the difference the correction factor will make.

see pic.....

 

[JeepSound 10+ year member]

all you need to remember is that is needs to maintain it's squareness and you always measure the length down the center. if your port is 2" wide, then you need to end you first port board 2" from the back of the box. if it needs to turn, then you need to have you second port board 2" from the back of the box.
Also, not mentioned yet in this thread, is the end correction factor. a correction factor is needed if the port shares a common wall with the box. the correction factor is simply adding 1/2 the port's width to it's length.

this is from JL's website...

"The effective length of the port is found by adding an end correction factor. An end correction factor is necesary because more often than not, one wall of the port is also one wall of the enclosure and this wall extends beyond the end of the port thus effectively adding length to the port (remember, the driver can't "see" the length of the port, it can only go by what it "feels" is going on)."

if you didn't add the correction factor, don't worry too much about it. in your case adding 1" to the port's length will probably only make about 1hz difference. the wider the port (and the more port area) the bigger the difference the correction factor will make.

see pic.....

For some reason I never really thought of making it L shaped, that post and picture helped a lot.

I decided to change it once again to 35hz with a port length of 18"s. So basically it'll look like that drawing.

Getting started on it tomorrow //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[punch 10+ year member]

did you not look at the "box plans stickey" on this forum....

 

[JeepSound 10+ year member]

did you not look at the "box plans stickey" on this forum....

Somehow I missed that. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

But I looked at it this morning.

I liked the 2 ft/3 at 34hz plan and built it today. I'll post pics tomorrow

Unbelievable difference going from sealed to ported. It's definitely louder, lower and maintained good SQ.

I'm definitely satisfied with it considering it was my first ported.

 

[mlstrass 5,000+ posts]

Congrats on your first box build, and the improvement over sealed...