I am a total newbie to building sub boxes that are to spec, I am in need of or well attempting to desing a new sub box that will give me more room in my trunk + be to spec to what the manufacture says my subs should run for a box size. I plan to build 1 box with separate chambers in it for each sub + each chamber with a port.... Here are the subs I have and the specs to build to.....


Make/Model: Image Dynamics, IDQ12D4

Small:
1.0cuft
freq.: 32hz
Port diem. 3IDX15.5" long

Normal
1.5cuft
freq: 30hz
Port diem: 3IDx14.375"


Now I have these specs but have NO clue on what size box these specs need to be operational.... My current box (not to spec) measures 30X15X14 (Length, Depth Height)....

Like i said I am a total newbie here so any help would be great.....


I think since I am trying to gain space in my car the small setup would be best out of the 2 but like i said i really have no clue....

it depends on what you want... a small sealed enclosure will let you pump more through the sub and sound alot cleaner. a large box needs less power and sounds alot boomier... i dont know how tto describe boomier but the subs move easier then in a small box. building a box right depends on what you want to hear and the equipment that will be going into the box! if you have a weak amp i reccomend building a bigger box.... http://www.diysubwoofers.org/ browse this site and it hase some helpful hints but it is a bit harder to fallow!good luck!

Well I was thinkiing about going after the small enclosure for the crisp sound and also the fact it would make the box overall smaller for my trunk... Right now the box i have can be too boomy for my taste and at others not loud enough.... but that verys from music style so thats not really the subs fault.... As for power I have a crossfire mono block amp that produces more then enough power to blow the crap outta the subs lol so I dont have issues there..... I just need a box that will work better with the subs and give me more room in my trunk then this bulky one....

Is your current box sealed?
If yes it is HUGE! You're looking at over 2.5 cubic feet. Even if there are 2 subs in there that is big box for 2 in a sealed. I recommend porting your current box.

But, when porting a box, don't simply place a pipe of any length in there. You will need to carefully tune it according to the speaker.

If your current box is for 2 subs I recommend installing 2 ports. Each port, 3" Diameter 15" long. THat should work well for you because each sub is seeing roughly 1.25 (or slightly more) cubic feet.

__________________
Nostalgia just isn't what it used to be.

Well my current box is ported, the guy who I bought my subs kinda set me up

He told me to take 2 3" pipes that are 4" in length and install them.... I am guessin he was way off then lol....

I am thinking about going back to a sealed enclosure, so I think I am going to cut my current box down to a smaller size I had been given a dept of 9.75 for the setup on a sealed box for the 2 subs so I think I will try this to the box I have, so I would just cut the 15" down to 9.75 and reface the box so its sealed and see how it works, dunno how stable the box will be in the car without the risk of tipping sicne I dont really have anplace to securly mount it..... May make a MDF spare tire cover yet and mount it to that.... but I have nothing to loose, I want trunk space so i will try this first....

I am a fan of ported.

Yes, what he told you was way off. With ports so short, your box is tuned too high, causing a frequency spike in the upper bass range (my guess is around 80 hz, but that is just a guess) which may account for the "boomy" sound you have talked about. Before making a sealed box, try extending the ports to 15"

You were given specs that tuned your box to crap. Before canning the ported idea, try a correcting to a proper ported.

If ported is done wrong, you'll think all ported sucks
If ported is done right, you'll know that ported rocks.

__________________
Nostalgia just isn't what it used to be.

but sealed wins more comps