View Full Version : I wanna try a not so common box, for 4 15's. Need advice.....

05-26-2009, 12:37 AM
SO I literally just put my setup in about 3 weeks ago, it wangs as it is, but I fudged a few things that Im not happy with. Its not much louder than my old setup with only 2 15's in 10cubes on 1000rms. But that was subs up, port back, and 130" of port

I dont know how much of a difference port area makes in volume.

My new setup is a wall, pictured here. Its got a good bit of volume, but I feel little port area and possibly just the design not liking my car is killing my overall volume.


So like I said I fudged up a little, as it was my first wall, trying to gain maximum airspace I went a bit to close tot he rear seats when folded up, and the subs are almost touching, so Im sure if I played them without the seats down, **** would hit the fan. I also used thin MDF and just braced the **** out of it (and to my credit, the baffle flexes none at all)

So if I do decide to build another box, I think I want to make it different, with the front looking like this. Ive seen a few builds like this, but dont know the fine details. Id like to make a square/diamond port in the center of the box and have the subs inside of it, one on each baffle. Front of box looks like this.

****** picture I know, but to give the idea.


I ran a box very similar in shape to this, about a year ago, but I low volted the amp within 10 minutes, and junked the entire setup. quite a different design as it was subs back, port up and not walled. But same box shape. I'll have to try and find my old threads for how big the final cubic feet was on this box and Ill have a good idea of what I have this time.


My only concern with the new box I want to build, is the port, and how deep Im going to have to go for my tune ( to be determined ) and


Just throwing the idea out there. Id really like to stick to the wall design, as my rear interior is pretty much ruined and Id like to keep it hidden lol, plus Id like to used all 4 of my drivers. Just need some tips advice and I'll go from there. If I decide to build this box, I will start in the next few days

05-26-2009, 01:13 AM
Based on some reading I did in my old threads, the last box (last one pictured) was about 16.5 cubic feet. Ill try and plug that into a port calc and see what kinda depth I need for a 16" X 16" port

EDIT: I tried 16.5 cubic feet with a 16X16 port @ 38hz in the carstereo port calc, and I get about 16" depth. But I am unsure if these calc need box volume, before, or after all displacements including port... gonna need some help on that part before finalizing

05-26-2009, 01:23 AM
The box you are trying to make in the pic you sketched is a compression chamber

05-26-2009, 01:27 AM
Thank you, didnt know the name, should help when I get some time to do some research tomorrow. Any gains/downfalls that you know of off hand?

Mind you this is a relatively low power (2500ish rms) setup

05-26-2009, 10:36 AM
Personally I'd figure out how to get 16-18cubes NET tuned to 38-40Hz with 16^2 of port area per cube. 18^2 would be even better if you can make it fit.

Port in the middle will add bracing to the enclosure, but most say port on driver's side is the loudest...

05-26-2009, 11:52 AM
Yeah, that barely looks like enough port area for 2 15's.

05-26-2009, 01:02 PM
Yeah, that barely looks like enough port area for 2 15's.

Are you talking about the box that I have installed currently?

The box that I sketched up, the port would be 16X16... 256" of port......

Mind you the subs would be mounted inside and take a little bit of it up, I could stretch it bigger no problem.

I just have no experience with this type of box and need some advice on building/bracing/tuning

Im probly gonna build the box INSIDE the car to, so its gonna be really tricky, never done that before

05-26-2009, 03:58 PM
Does anyone know of any compression chamber builds like the one I sketched up? I would LOVE to see some pics of the setups