need help on box build

culzero · Post by **culzero** » Mon Jul 21, 2008 7:07 am

ok guys i finally have all my subs and plan on building my box over labor day weekend but i need help on designing the port (i'm not very good at it)

Ok here's what I have to work with. It will be (4) Ti12d Elites mounted in an upwards facing box with port in same direction.

Overall Box Dimensions: 46"W x 27"D x 21"H
Internal Box Dimensions: 43.75"W x 24.75"D x 17.625"H
Internal Box Volume before Port: Approximately 11 cu ft
Preferred Tuning Frequency: Somewhere between 25Hz and 30Hz
Maximum allowable port opening: 6" x 14"

The box will be built out of 1 1/8" MDF with a double baffle for mounting the subs. Also I will be using 1/2" MDF to make 45s in all corners and the port (I may make the port out of the 1 1/8" if I have enough airspace)

Any help would be appreciated.

flogger11 · Post by **flogger11** » Mon Jul 21, 2008 7:08 am

Im pretty sure you are over-building your box, any other opinions?

KHPower · Post by **KHPower** » Mon Jul 21, 2008 7:14 am

Overbuilding?? Thats just right! Did you hear how many elites hes running?

The bracing would be key in such a big box and if you are properly powering those subs

How much power are you pushin?

What kind of ride are you using?

Also if you need a 6 x 14"" port you can make a slot port or a square port. Also if you can find some pvc you could use that but I would just make a slot port or a square port if you want to use the 1 1/8 wood.

I personally use a square port that is 5.65 '' x 11'' and it works well for me

Someone else might want to chime in about the elites but I thought those subs liked smaller boxes and high tuning ?

Post by **kg1961** » Mon Jul 21, 2008 7:15 am

that will be so loud what did you find to power all that???like to see pics!
I would make them a little smaller
good luck

soth · Post by **soth** » Mon Jul 21, 2008 7:23 am

Wow, yeah 4 of those bad boys are going to pound. As far as overbuilding goes, I'd say go for it. More bracing the better no doubt. Did you say you were going to put them in seperate chambers?

As for ports goes, what does PG recommend, slot or round? What hz are you going to tune it at also? That is if you're not going sealed.

Good luck.

culzero · Post by **culzero** » Mon Jul 21, 2008 7:32 am

KHPower wrote:Overbuilding?? Thats just right! Did you hear how many elites hes running?

The bracing would be key in such a big box and if you are properly powering those subs

How much power are you pushin?

What kind of ride are you using?

Also if you need a 6 x 14"" port you can make a slot port or a square port. Also if you can find some pvc you could use that but I would just make a slot port or a square port if you want to use the 1 1/8 wood.

I personally use a square port that is 5.65 '' x 11'' and it works well for me

Someone else might want to chime in about the elites but I thought those subs liked smaller boxes and high tuning ?

I originally planeed on using (4) Tantrum T1200.1 but have no leaned towards (2) Sundown SAZ - 3000D.

My Ride is '02 GMC Envoy

I'm looking for an SQL type of box. PG specs state 2.75cu ft @ 25Hz per sub for SQ and 2.25cu ft @ 31Hz per sub for SPL

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culzero · Post by **culzero** » Mon Jul 21, 2008 7:33 am

soth wrote:Wow, yeah 4 of those bad boys are going to pound. As far as overbuilding goes, I'd say go for it. More bracing the better no doubt. Did you say you were going to put them in seperate chambers?

As for ports goes, what does PG recommend, slot or round? What hz are you going to tune it at also? That is if you're not going sealed.

Good luck.

It's going to be one chamber. Don't have the space to make individual chambers.

Post by **kg1961** » Mon Jul 21, 2008 7:36 am

just be careful make all the subs great the same power and wire lenght.
one sub move more it can sound like SH%@
test both amp make sure you have the same output
I would use 3 and have each in its own box might sound the same too

culzero · Post by **culzero** » Mon Jul 21, 2008 11:49 am

i'm going to try and design this in AutoCad first but my problem is that I do not know how long the port needs to be? If I use a 6" x 14" opening how long will it need to be to be tuned around 28Hz.

That is where I'm stuck. If I can get help with that number I'll be good and can start the final design in AutoCad.

Post by **smgreen20** » Mon Jul 21, 2008 2:28 pm

I did it on winisd at 27 Hz, port came out to be 6 x 14 x (20.375" long)

That's going to be stupid insane.

KHPower · Post by **KHPower** » Mon Jul 21, 2008 2:58 pm

smgreen20 wrote:I did it on winisd at 27 Hz, port came out to be 6 x 14 x (20.375" long)

That's going to be stupid insane.

That sounds like it is gonna be nuts!!!

Can the Elite hit good lows? I was always informed of the sub lacking in this area , I might be thinking of another sub.

I will also double check on Bassbox tonight for ya but what smgreen20 came up with sounds about right

with 1 1/8 '' mdf that box might not even flex

culzero · Post by **culzero** » Mon Jul 21, 2008 3:08 pm

thanks guys

i'm hoping that it doesn't flex at all. i'm just hoping that i'll be able to lift it when its all said and done with

it looks like its gonna be a 4 month project

KHPower · Post by **KHPower** » Mon Jul 21, 2008 3:12 pm

Make sure the saw your using can cut through 1 1/8 '' MDF

I wish I could get my hand on some of that size

culzero · Post by **culzero** » Mon Jul 21, 2008 3:20 pm

i have a delta X5 10" table saw with a 50" besmeyer fence, i think it will work

KHPower · Post by **KHPower** » Mon Jul 21, 2008 3:24 pm

culzero wrote:i have a delta X5 10" table saw with a 50" besmeyer fence, i think it will work

Sweet! Well , if I can do it with a tiny Craftsman table you should be good with your Delta

joyride · Post by **joyride** » Mon Jul 21, 2008 7:10 pm

That is going to be one heavy box. I had to cut through an entire lift of 1 1/8 MDF last summer (1 rip, 3 crosscuts each sheet) and I wanted to die. Just be sure to upload tons of pics, cause I want to see this thing.

And Im jealous of your saw....I miss my RT40. You just cant go wrong with 7.5 horsepower in a table saw.

brenzbmr@sb · Post by **brenzbmr@sb** » Mon Jul 21, 2008 10:23 pm

i would say put two in shared chambers for each amp. not only will this
strenthen the box it will keep it rigid.

run it at 2.5 cubic ft tuned at about 330hz, any lower will not make that much impact in your envoy.

port do a vent for each pair this way lenth will not be a real issue since u can bend it for your needs.

if u have any other questions about the elite let me know, and to the person asking if the elite hits low

yes it does.

just so u all know for those that dont, i run mine in 4cubic ft tuned at 30hz

anything from 25 to 35 is so excessive that is unnatural(lol)

i wish u guys could hear it. i have guys with 18s that cant hit like this.

the car itself isnt really that loud outside(i deaden the crap out of it)
but inside it s insane.

have fun and those sundownz amps are nice.

also keep in mind that if your looking for upper bass output
to be loud you grabbed the wrong woofer. it wil not do very well above 50 but if u want a crap load of low end

boost at about 30hz on a processor and hold on.

aloha

culzero · Post by **culzero** » Tue Jul 22, 2008 4:53 am

brenzbmr thanks for the input. unfortunately the overall box dimensions i gave at the beginning of this thread is all i have to work with. So after port, bracing and woofer displacement i'm goin to be lookin at only about 2.25 cu ft per sub. If i can find a way to make the box a little larger i will but right now that appears to be the largest i can go without making a wall or building the box in the envoy.

smgreen could I ask you to recalculate the length for 30Hz. I would like to see what the difference is. thanks for the help guys

Post by **smgreen20** » Tue Jul 22, 2008 2:08 pm

I got 15.125" long at 30 HZ

culzero · Post by **culzero** » Tue Jul 22, 2008 5:49 pm

thanks for the new numbers

now here's a new question. i got people tellin me i should fire the subs up with a rear firing port, what do you guys think?

subs & port up? or subs up / port rear?

if i go rear firing port i can possibly make a larger opening for the port

what yall think

Post by **smgreen20** » Tue Jul 22, 2008 6:43 pm

I had a 94 Bravada and I found best results firing both straight up, but then again I didn't make a box that took up all the cargo area. That might be key too.

Your SPLers will tell you to do subs up and big'ol ass port back.

Post by **stipud** » Wed Jul 23, 2008 6:44 am

Acoustically speaking, it is better to have your sound waves coming from the same plane. This way you get less chance of cancellation, which detracts from both SPL and SQ. However, depending on the car and the port aim, you might not have cancellation, in which case having the bigger port area will make it louder. As such, I don't think there's any "true" answer, other than try both and see which is best

Though, there's gotta be a reason all these SUV SPLers are running rear firing ports with top-firing subs. Maybe it just works... who knows? I'm no SPL guy

culzero · Post by **culzero** » Fri Jul 25, 2008 10:48 am

thanks stipud that was informative

however i don't want to build multiple boxes in order to try both out. So i guess i'm just gonna have to suck it up and choose one of the designs

if i do go with the rear facing port; i could probably make a port as large as 9"W x 40"L X ?"D I would need to try and figure out the overal length of the port to be tuned at say 30Hz.

thanks for all your input

culzero · Post by **culzero** » Mon Jul 28, 2008 9:01 am

after further review of what i have to work with. it looks like i'll be building the box subs up and port back. now i need to ask for some more help from you guys on the port length so i can get this tuned properly.

I'm between a couple different port dimensions so if you guys dont mind giving me an answer for all so that I can decide.

Option 1: (150 sq in of port) 40"W x 3.75"H x ?L tuned @ 30Hz

Option 2: (240 sq in of port) 40"W x 6"H x ?L tuned @30Hz

Option 3: (320 sq in of port) 40"W x 8"H x ?L tuned @30Hz

And after sub displacement and bracing I should be right around 9 cu ft net.

Thanks for all the help.

and just an FYI 4x8 sheet of 1 1/8 MDF is heavy as sh**

KHPower · Post by **KHPower** » Mon Jul 28, 2008 10:37 am

I know this isnt the answer you are looking for but I would go with option 3 and then go to a few SPl comps

need help on box build

need help on box build

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