View Full Version : Noob making a ported box...

12-13-2005, 02:21 AM
the subs (2): http://www.crutchfield.com/S-Zl3TTvFjbHT/cgi-bin/ProdView.asp?I=1081240W

This is about all the information I have:

"Recommended Ported Box Volume: Infinity recommends a ported enclosure with an internal volume of 2.0 cu/ft with one 4" diameter x 12-1/4" long port."

Now for the Q's... so i can draw a plan up

So ive got the volumes i need... does it matter what lxwxh combination I use to achieve this volume or would there be a specific one that would give me the best results?

This might sound stupid, but what exactly is a port, where does it go, and how do I tune it?

Which way should I draw the box facing? should the port and the subs generally face toward the front or the back of the car?

does the box have to go right up against the back seat? the way that my trunk is, its narrower right up against the back seat because of the wheels and then it widens up...

agiainst the back seat: Length: 19" Depth: 36" height" 17"

6" away from the back seat(where it widens up): Length: 41" Depth: 30" Height: 19.5"

as you can tell, the bottom of my trunk is a bit slanted, getting lower the farther you get from the back seat. Will this be a problem for the subs or box?

When I start building, what should I do first before I start cutting up the wood?

I'm building a dual box, how much space should be inbetween the 2 chambers?

umm please dont let this topic die, i am a total noob so ill really appreciate if you guys try to answer as many of these Q's as you can. I'll update the topic with more Qs and pics once I get started.

12-13-2005, 09:49 AM
As long as the NET volume of your box, after you subtract the volume of the ports and the subwoofer displacement (about.1 cubic feet per sub if you cant find the spec.) is 2.0 cubic ft. then the 4 x12.something port will be fine and the box will be tuned to infinitys specifications, but you might want to try to build a box with more port area than 12 sq in from that 4" diamater port. 30 square inches will be louder and the box will have lower group delay(horter time in milliseconds between the note from the face of the sub compared to the note coming off the back of the sub and out the port, basically "punchier" bass).

12-13-2005, 05:27 PM
i found this topic... http://www.caraudio.com/vb/showthread.php?t=100240

this guy has almost the same car (my nissan sentra is 2001) and pretty much the same subs as me... so im gonna try to copy his box... is this a good idea? I just need the dimensions for the port and individual chamber length...

12-14-2005, 12:09 AM
here is a thread that is step by step:

and theres a person on this thread that actually used that thread to calculate the dimensions for someone. i followed this to see what he did:

hope it helps if you use it!!

12-14-2005, 01:17 AM
These plans were made for pretty much my car and infinity reference 1230W, mine are infinity reference 1240W...


First, do you think it will work to just use these plans (I plan to add a divider in the middle though)?

The guy who used these plans posted pics and made this:


Is this a good design? and just one Q, what are those 2 holes at the back? one of them has some black switch in it (what is that?) and the other is open.

12-14-2005, 09:22 PM
f it, i give up. are these any good?



12-15-2005, 10:11 AM
f it, i give up. are these any good?



no...if you don't want to make one yourself PM Moe Lester for design or he can build you an enclosure. PowerNaudio will give you designs also.

12-15-2005, 10:31 AM
i have the 12" version of these subs and just built a box for them... pm me and i'll give you plans

12-15-2005, 06:07 PM
well can anyone tell me whats bad about those boxes on ebay? they are tuned and use the same materials...

12-15-2005, 06:33 PM
They are usually the smallest enclosure possible for the driver and tuned very high so you get horrid low end extension. and WAY overpriced

12-15-2005, 06:52 PM
2.4 cubic feet per chamber
Tuned to 30HZ

??? doesnt sound anything like what you mentioned