Bakerman

Lets start with my available dimension. Im building for the back of a Jeep Cherokee. My width is set at a 39" max. Height isn't a hard stop, but I would like to keep it under 17". No restrictions on depth that anyone would get close to designing anything like this. The driver is a Skar ZVX-8 So to the point, I'm not asking for someone to design a box, but just incase anyone asks, I went ahead and got details covered. Ive been wanting to try out my skills at a 4th order. My main two resources are Steves old write up on the topic, about a 2:1 ratio, manufacturer specs on the sealed, twice the area for the port, tune high, etc. So I designed a box that is 12*12*12 for the sealed. With displacement, it comes out to a net volume of .67 c/ft and the manufacturer recommends .65c/ft. So I feel like Im golden on that. The ported section is 24.5" wide, but the same 12" tall and 12" depth. The port measures 10.5" (box height minus wood thickness) and 2.85" wide with a length of 6.90". (I know the decimals are hard to actually get on a table saw, but its the math, work with me) This gives me a ported section with a net of 1.35c/ft, 14.45sqin of port area, and a tuning of approximately 50hz. Now when I go to put this in WINISD, not only is my peak at like -5db, but the low is 11hz and the high is somewhere in the 100'shz range. Then I found this super complicated set of math forumula's that suppossed to give you the perfect dimensions based off the specs of the driver. You can find the writeup at this link. Anyways, by the time I do all the math, with an S value of .7 at 3db peak, it gives me similar specs. I get a sealed portion of .60c/ft net and a ported section with 1.5c/ft net and a tuning of 47hz. This seems more "exact" than SMD's formula, so why not go with this? Well, when I plug it in to WINISD i get similar plot points as expected. So at the end of the day, should I go with my gut and build it out to specs similar to above, or am I doing this all wrong and have no concept of what I am doing? My goal is to have a daily driver with a loud setup, but is clean and can actually be listened too. So i thought if I can design a box with a good flat response across the spectrum of about 40hz-100hz I would be good. But this is turning to be a bit complicated. Pic for attention, just to show you I actually do this math by hand. Im a bit old school

But, just because you can, doesn't mean you should! Different woods have different "rings" or resonant frequencies. Hexibase did an amazing videos showing the dampening effects of many different woods, and plastics (3d printed enclosures). Of these, mahogany actually had the best dampening effects, making it great for subwoofer enclosures. And to no surprise, Pine did the worst by far, only outdone by one of the plastics. And you argue about your port area being an effective means to combat the fact that your port wraps around the subwoofer. However, if you simply decrease the port area to something smaller, and more in spec with what the sub actually needs, then you wouldn't need such a long port. These small details, along with many others may not make a large or even noticeable different by themselves...but when you put them all together it really makes a HUGE difference in the overall quality. Its kind of on the same level as when an installer uses butt connectors and zip ties, or actual soldering, wire loom, and cloth tape. Sure, that one butt connector may not make any difference, but over the course of the entire installation, the more expensive and time consuming option gives ten times better results. In the install case, its visual. However, in your box designs, its literally performance. But, considering you are making boxes out of "cheap plywood" I'm assuming you are years away from learning these things. Keep at it. Just don't charge people for your work. I've been doing this for years, and have a degree in electrical engineering, and I still invite people over so I can hook their shit up to my equipment for free of charge.

Man, decades? Well, nearly a decade since I posted anything of valuable content. Lol. 2012 I believe. But I'm back for now.

Good to see N8, Skippy, and LT Smoke still creepin. The rest of you, i don't remember yall.