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View Full Version : Box design ported for 4 8" REx subs..



rsxs1212
04-28-2010, 12:54 AM
I want the box to be about 40x14x14 or something like that to be right around 4 cubes.. Ive built some sealed boxes but this will be my first ported.. Ive had ported ones built for me but im ready to give it a shot. I looked at t line boxes but they seem a bit complex.. So the question comes about of aero port or do a slot port.. Id like it to be tuned to about 33hz if that is possible... The port tuning is what I dont quite understand and how to find port length.. I found a nice calculator for it but just would like to get some advice from the pros..

Thanks in advance for the help.. I had audioque 15" hdc3's but was too much and took up way to much space for me so I thought this would be a cool project and im going to rhinoline the whole back of my truck as well as the exterior of the box.. All this is going in a nissan xterra just for everyones knowledge.. I like listening to rap and then rock some of the time too.. I used to just be into sealed boxes but when ported boxes are constructed right I think they sound just as good

Thanks for the help

iamamp3pimp
04-28-2010, 02:24 AM
Youre in bradenton. Idk if you have the tools or not, but if youre looking for a hand, you should swing by the build-spot.


shoot me a PM, i am in Hudson.

-Robin

rsxs1212
04-28-2010, 02:02 PM
I have basic router, table saw, tape measure and things of that nature. I should be fine as I have built sealed boxes I just dont know what to do as far as dimensions

rosshimself13
04-28-2010, 04:37 PM
if you have win isd, a calculator, and sketchup i would suggest you read this right here (http://caraudio.com/forum/enclosure-design-construction-help/215849-simple-edu-how-design-ported-box.html) and call it a day, its really simple, and all you need really is the displacement of your sub

Edit: you dont even need sketchup, but it will allow you to accurately draw your box to give you an idea of what it will look like

DonH
04-28-2010, 04:39 PM
way to large for 4 8's dude. i have a 4 8" box i would sell for 80+shipping but measurements are 49" x 12.5" x 12" with interchangeable round ports....double baffle with black carpet, red paint where the woofer mount. lmk

RAM_Designs
04-28-2010, 10:03 PM
40x14x14 gives you 3.48^3 before any displacement. Assuming .6ft^3 for a normal slot port and .4ft^3 for subs and you're in a good area(around 2.5ft^3) for 4 RE8's.

on1wheel01
04-28-2010, 10:06 PM
4 cubes is way to much for 4 8's. I just built a box for 3 e8's 40"w 12"h 14"d 2.2 cubes tuned to 32. I suggest doing similar to that a little wider for port and subs back or up, or you can do subs up or back and port to side.

Box is done paint just needs to dry im pretty happy with it http://i79.photobucket.com/albums/j160/grnreaper01/63baf00b.jpg

rsxs1212
04-28-2010, 11:39 PM
well like mryan423 said after displacement it comes down. Im just looking at overall box volume without factoring in the ports and all.. dman1 I would do the box but theres no way i can fit 49 inches in my car.. onwheel01 i like ur box design i just need one more 8" sub in there maybe a few words of wisdom to help me out.. I just want to make sure i do this right because i know the box can make or break the subs performance

rsxs1212
04-28-2010, 11:40 PM
and i dont have win isd or know what that is, I have a mac and if that is operable perhaps i can mess around with it some

on1wheel01
04-29-2010, 12:11 AM
well whats the total width u have to work with 8x4 is 32 then take in 1" apart from each other or so. You could do subs back or up and port to the side.

RAM_Designs
04-29-2010, 12:58 AM
Also, with a 14" tall box he can offset them so that they won't take up as much space...I did this with some older RE8's just to make it look different.

rsxs1212
04-29-2010, 08:11 AM
I have 42" of width to work with.. amazing how much smaller my cargo area is in it compared to the explorer I had... also amazing how I have no repair bills on this and the repair bills on the paid off explorer were more then payment on the xterra !! LOL

anyway I think I can fit the subs comfortably next to each other without much problem but Maybe not..

on1wheel01
04-29-2010, 02:10 PM
OK how bout this 42" wide 14" deep 14" high port out the side 3.5" wide port. Gives u 2.5 cubes tuned to 30.7, 43.75 inches of port. Should be pretty loud. That way u can fit the subs side by side with no probs and give about 1.5-2" between subs.

rosshimself13
04-29-2010, 03:00 PM
14x14x42 outside, 2.19 cu ft 12.5x3x38.5in long port tuned to 32hz, subs forward or top, port side, guessing they displace.4 total on subs, rough design, im a newb but i think this is about right... it might not be perfect, check my math

edit:if you only have 42'' this wont work, you need room for the port to fire took about 20 minutes to figure all the math, and **** out while drawing it

rsxs1212
04-30-2010, 12:38 AM
That mock-up that rosshimself13 did looks pretty dang good to me.. easy to make too.. I think I will probably just end up going with that unless anyone sees any problems with those plans..

on1wheel01
04-30-2010, 01:51 AM
he said it wouldnt work if u only have 42" to work with

rosshimself13
04-30-2010, 12:18 PM
he said it wouldnt work if u only have 42" to work with

true story

Bumpin' Goalie
04-30-2010, 12:30 PM
I'd go port forward or port up just to avoid having it fire into the side of your xterra. That way you can use all 42".

Aero ports work well for this kind of thing, if a slot port is not conventional.

rosshimself13
04-30-2010, 12:56 PM
ok.. took me longer to edit the box and still be somewhat happy with it, than it did to just do it the first time, mind you im in iraq.. so this is my time off and i am bored

40x14x14, 2.44 cuft, 32hz, 12.5x2.5x27.25 port, could be bigger, but it kinda threw the design off when i tried

if you only have 42 inches, this give you 2 inches of room for the port, i would be mindful of that if you put it in just right you could manage to lower your tuning quite a bit... :fyi:

rosshimself13
04-30-2010, 12:57 PM
that would actually work better, good idea.. on the port firing up just make an L port, would still be same size, and same tuning but have port up and go down to the bottom of the box, then you could have the subs face up as well, unless his subs have more than an 8'' mounting depth, i am a noob and didnt think of this

rosshimself13
04-30-2010, 01:32 PM
it might be a tight fit... but i like this one more, you could, if the subs dont mount too deep have them face the same direction same specs as first design, but L port.. this was all just for practice

on1wheel01
04-30-2010, 01:57 PM
that one would wang but doibt it would fit.

rsxs1212
04-30-2010, 02:06 PM
Yeah I think that would be a tight fit.. and the actual cargo area is wider then 42 inches but my wheel wells only have 42 inches of room between them.. There is actually 43 but ya.. so I dont think the side would be terrible.. I was considering flipping the box, keeping the same dimensions but having the subs fire upwards and then the port towards the hatch.. is there a way i could use the whole length of the bottom of the box with that setup??? those REx 8" subs only have a 4.5" mounting depth so I dont think it would be hard at all to do so..

Thankss

RAM_Designs
04-30-2010, 11:04 PM
Stagger the subs and you can easily do everything firing to the back...enough room for a 8-9" wide port if you want.

Bumpin' Goalie
04-30-2010, 11:09 PM
Stagger the subs and you can easily do everything firing to the back...enough room for a 8-9" wide port if you want.

This. Plus staggering looks pretty slick.

rsxs1212
05-01-2010, 01:40 AM
hmm many options.. It will be interesting.. The staggering does sound pretty cool I might try that as well.. Im excited to see how this setup will sound..

RAM_Designs
05-01-2010, 09:46 AM
hmm many options.. It will be interesting.. The staggering does sound pretty cool I might try that as well.. Im excited to see how this setup will sound..

I did something just like this with the older RE8's and they sounded great. Did like 3ft^3 tuned to 35hz, staggered subs, looked good.

rsxs1212
05-05-2010, 03:30 PM
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0236.jpg
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0237.jpg
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0238.jpg
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0239.jpg
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0240.jpg
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0241.jpg
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0242.jpg

What do you think?? Im going to pick up the roll on liner today or tomorrow to do the outside and make bars for some red LEDs in the port.. not bad I didnt think..

rsxs1212
05-05-2010, 03:31 PM
http://i92.photobucket.com/albums/l23/rsxs1212/IMG_0243.jpg

rsxs1212
05-05-2010, 03:32 PM
Only thing is i want to make something for the rest of the port out of mdf or something like that so it looks uniform across the front

on1wheel01
05-06-2010, 05:02 PM
What u could have done is make the overall box 3/4 deeper and cut the front plate shorter so it fits in the box it's self, or had the front plate go all the way across and use a flush trim bit to get the port cut out.

on1wheel01
05-06-2010, 05:03 PM
Also looks like u may have used to many screws in the front piece usually want it somewhere between 3" - 4" spacing. But not to bad

iamamp3pimp
05-07-2010, 06:36 PM
cut a square to fit, then cut a ring.

who designed that?

rosshimself13
05-07-2010, 07:57 PM
i think he took the design i posted up, but i figured it was a given that the front would be flush with the port... no questions were asked and no money was paid, i would have made the front 1 1/2 in shorter in height, to avoid that.. the sketch is on this thread

on1wheel01
05-08-2010, 12:06 AM
no moneys paid cuz he didnt offer to pay. But yea box fail.

RAM_Designs
05-08-2010, 12:23 AM
I think you need more screws by the port...don't want to risk not having enough.

RAM_Designs
05-08-2010, 12:27 AM
Also looks like u may have used to many screws in the front piece usually want it somewhere between 3" - 4" spacing. But not to bad

3-4" is still way too many...minimum 3 per side to get a snug fit on both sides and the middle, and maybe 10" spacing if needing more than 3. The screws are just there to hold the MDF in place until the glue dries.

rsxs1212
05-08-2010, 02:19 AM
What is the damage in having too many screws?? I will post up pics when its all in the car, I took in account having the piece on the outside rather then sliding in for measurments.. I had a few members pm me offering to design for a price but I saw that sketchup and put it in the calculators so it all looked good to me.. Im a teen and didnt think it was that bad for being a rookie box builder other then simple sealed boxes.. Its going to look nice when its all installed, I dont have a router to have the piece cutout around the port im working with a table saw, circular saw, jig saw, sharpie and a tape measure..


Found a scrap of 1/2 acrylic and I etched nissan symbol into it with my dremel looks nice.. gonna wire up some red LEDS i have to go along with it.

If someone wants to make the box the right way and send it to me for free I will take it, otherwise i am happy with how it turned out..

rosshimself13
05-08-2010, 03:02 AM
i am happy with how it turned out..

all that matters, i along with everyone else here were just pointing out flaws, so that if you didnt now about them you can now fix them.. or next time not make the same mistakes... so enjoy it..

RAM_Designs
05-08-2010, 08:22 AM
What is the damage in having too many screws??

In most cases, nothing. It's just extra money and work spent on something that doesn't need it.

on1wheel01
05-08-2010, 08:37 AM
Well it can weaken the wood and create possible fail spots.

rosshimself13
05-08-2010, 03:19 PM
the screws are only really there to hold it together for the glue to dry... the actual strength comes from the glue as backward as it sounds its the truth

rsxs1212
05-09-2010, 02:01 AM
Gotcha.. I used tightbond as you can see in the pictures.. The box seems very solid.. Considered doing bracing but I really do not think it will be necessary.. And my screws are 3-4 inches apart each, Im not sure why it looks like there are so many right along the port, 4 year old camera, Im really not sure what happened..

Thanks