# OS stroker 18D2 box specs?



## NJPCRX (Jul 25, 2012)

I just bought a NIB original 18D2 stroker  I have 2 6" precision ports that only have 17" of useable port each. The owners manual specs call for 5.87 cuft box with 56sqin of port. But it wants the ports 28" long to tune to 35Hz? I need help adjusting this to work with the port length I have to work with. I found another site, with a guy trying to sell a used stroker 18, and he listed a bunch of box specs. He said 6.72 cu ft with 2 6" ports at 16.5" length each for 35HZ? That doesn't seem quite right either. When I run those numbers I get tuning between 33-34. The post is years old and I don't belong to the forum to ask. Does anyone have or remember specs that work for this sub or any advice? Is a bigger enclosure better with the OS stroker?


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## for2nato (Apr 3, 2012)

Do you have accurate displacement specs for that stroker? Because a slight fudge of that spec could throw of your tuning. But realistically are you going to be able to tell the difference between a box tuned at 35hz and one tuned at 34hz? Because I seriously doubt it. Load the thiel small specs for the woofer into winisd and tune it to the ports you have at 35hz and see what you come up with for port length

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## NJPCRX (Jul 25, 2012)

Yeah, the difference won't be noticable at all, I was just sayin. THe driver displacement is .43 according to the owners manual. What tuning will this sound best on music? I'm sure someone remembers...


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## TrickyRicky (Apr 5, 2009)

There are some enclosure blueprints from John Fairchild (if am not mistaking)...it had four triangle ports on all four corners of the enclosure where the sub was mounted. I have the blueprints in my PC somewhere but can't find them. Am sure someone here has them or know where to find them.


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## NJPCRX (Jul 25, 2012)

I have seen that box blueprint for the 4 corner ports. The thing is, i need to use these precision ports. I bought them for another project that never came about. So they are brand new just sitting in my garage. I wanna use the 6.72 specs I mentioned but I don't know where the guy came up with the numbers.


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## for2nato (Apr 3, 2012)

If you build your box at 7.5ft^3 with 2-6" round ports cut at 12.5" it will land you right near your goal of volume after driver and port displacement at 35hz.

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## NJPCRX (Jul 25, 2012)

So if I leave the ports uncut at 17" it will drop the tuning to 33-34 HZ, right? When I run your numbers nato, i get around 15" for port length. Box would be 6.67 cuft net. My original example was 6.72. Pretty much the same box.


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## for2nato (Apr 3, 2012)

Winisd doesn't account for port displacement. So I did a rough calculation for it. And yea of the top of my head your right about not cutting the ports you have and landing around that frequency. But personally if your wanting the best for music then you'll want to be a little higher than that in your tuning. Or you'll just have to eq out that freq just to level off the gain you get from the enclosure. My sub's recommend a 35hz vented enclosure and that is what i gave them for their temporary box just to test the manufacturers specs. And they sound good on everything from rap to classical. But I have to tone down the lower side of it sometimes or it's just too over powering in the real low end

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## NJPCRX (Jul 25, 2012)

could I just make the box a little smaller to compensate for the port length. If I take it down to 6 net the ports can be 17" and be at 35hz.


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## for2nato (Apr 3, 2012)

The specs I gave you would be for internal ports plus driver displacement at 34.9hz and a net volume of about 6.7ft^3. I could work up an exact number for you but the differences would be negligible

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## Oscar (Jun 20, 2010)

Did you finish building the box for that bad boy OS stroker?


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