Been working on the Girlfriends 99 Blazer and she wants some bass to go in the back. She bought a 12" sub and amp off her brother and she want's me to put it in. It's nothing spectacular just a 12" JVC sub and Pioneer mono amp. The current box is a tiny behind the seat pickup truck box and sounds loud but like crap in open cab of the blazer. I would have perfered her to have a 10" but what you gonna do. I have to build a box!

Anyhow I was thinking of building a slot ported box this time. I have no idea how to tune a box? or determine the size of the port. All I have ever built are sealed enclosures. I want it to be short enough to fit below the rear seats head rests and between the wheel wells and i'll just adjust the depth to whatever the cu ft requires.

Where can I find "Very Simple" info to design a ported box? The sub is a 12" JVC CS-GS5120. The manual I downloaded only show how to build a simple sealed enclosure.

Thanks! Chad

 

Ideally you'll want to model the subs specs in a program like winisd to determine the optimal box for your sub..

Or you can go with a "usual" box for a 12, which would be around 1.5-2 cuft, tuned to 33-36hz. stick with 12-15sqin of port area per cuft and you will be golden.

there are alot of sites that have programs to make a simple slot port box, just do a quick google search to find them.

 

I tried to help you out and put the params in WinISD for you. However, it didn't model well and gave crap numbers. If you gave it 1.75cuft tuned to 34hz it will probably do fairly good. If you want some enclosure design help let me know, I can whip out a design and cut sheet pretty quick if you can give me the two most important dimensions for it. Such as the max height and width, or height and depth. My program will figure it all from there.

 

Thanks man! I was thinking along the lines of no higher then 16 inches and no wider then 38 inches for a single 12" sub woofer.

 

Get all pissy and moody and start a fight over how "if she liked buying car audio off her brother, she should just have him build a box"

She will think twice about going with anyone but you the next time she has any car audio concerns.

 

Alright, got a couple of quick enclosures done for you. I took screen shots of each page for quick reference here and there's a PDF download link associated with each screen shot so you can download something with a bit more quality to it as the text has a tendency to get a little skewed in a screen shot.

Here's the two box specs. Both are 1.75cuft net tuned to 34hz, one is pretty standard with a round port the other is a standard slot port enclosure.


d/l = ludude1975 box specs.pdf


Here's the cut sheets for the round port style enclosure:


d/l = ludude1975 round port cut sheet.pdf

Here's the slot ported enclosure cut sheet:


d/l = ludude1975 slot cut sheet.pdf




The reason I gave you both is because I'm unsure of your building skills. Some find it easier doing a round port, others the slot. There will be no real difference in sound between either enclosure, so take your pick or hell build 'em both, lol. If you need any help deciphering anything let me know. The format is easy for me to understand, though I'm the one who wrote it so of course it is, some others have had a hard time of it. On any dimensions that aren't an easy decimal to convert to a fraction of an inch, there's nothing wrong with just rounding up, even to the nearest quarter inch, it simply doesn't make that big of a difference. Either way, I hope this helps you get things going on track.

BTW what part of Indiana you from?

 

LOL you can't talk sense with a woman!

Thanks, If it ever stops raining have to get me some MDF.
I live in Dunkirk up in south end of Jay County.