If only I got paid for this ...

[03BlackGT]

Alright this is the start of my newest sub enclosure. Its going to ported for 2 12" alpine type-r's pumpin 750 watts rms. As shown its going to be mdf sides and bottom and a fibergalss front. This one will be smoothed and painted i hope. Depends on how patient iam. Im not to sure what im going to do with the amps just yet. This thing is massive and is going to weigh a ton but i think it will be well worth it.

Do u all think i should throw in a capacitor? I get some crazy battery drain from just one type-r but i heard they are a waste of money? anyways tell me what u all think . By tommorrow i should have the rings in place and have the whole thing wrapped. Maybe a coat of glass. We'll see.

-aLeX-

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[kody]

That doesn't leave much room in the trunk for anything else but I'm sure you've realized that already. It'll be interesting to see the final product, make sure to take lots of progress pics. That will make a great how-to project for others interested in doing the same.

[tubpub11]

I would try doing the big 3 before getting a cap. (battery drain, do you mean your lights are dimming when your bass hits while your driving?)

[XoticGA]

Oh wow!

I'll take one to go, please! :lol:

[03BlackGT]

haha .. theres alot more trunk space than it seems in the picture. takes up about half of it though. and yes i was talking about dimming headlights and what not. i been meaning to do the big 3 but im not sure thats gonna be good enough. just wondering if anyone have positive results from a cap?

[AAS SC/T]

I have had one in both of my last two vehicles no dimming of lights. I also have a optima yellow top battery and 4 guage wire I and running 110 watts rms x 4 @ 2ohms and 400 watts rms x 1 @ 2ohms

[Lash]

Your ports are WAYYYYYY too small!! For one....a 1:8 max ratio is always a good rule of thumb to use for port height and width. By the looks of it each port is about 3/4"- 1" wide x 14" +/- tall (meaning roughly a 1:14 ratio).
Seconds....port area. Those 12" type-r's should have around 30-35 sq.in. PER SUB to perform properly in a ported enclosure without nast port noise. By the looks of it....you dont even have that much between the two.

Also..when doing a "T" design port....its always a good idea to put a splitter down the middle...otherwise turbulance may occur where the two ports join. Turbulance = no good...port noise can get louder than you think that way.

Do you even know what the box is tuned @ with the crazy arc you have for the vent?

I'm sorry to say it man...but I can tell just by looking at it that it's not going to sound how a slot vented box should. You may want to do some re-modeling before you get too crazy with the glass.
The craftsmanship does look very nice though. Just needs some fine adjustments IMO. :)

[MantaGreen97]

^I was thinking the same thing. The box design and craftsmanship look nice, yes; but what is that box tuned to? It can't be a very good tuning frequency... (?)

I mean I could be wrong but it doesn't look like you have enough port volume to have a good tuning frequency.

[03BlackGT]

Your both right. Its not tuned period. Ive done lil research as far as performance goes. I basically copied and tweek designs from other boxes ive seen for the ports. Im basically going for looks/space. You were right as far as the port size. Its 1 1/4" x 14" but was originally planned to be much wider with a divider, but because of the limited width in the trunk i had no choice. By no means do i even consider myslef to know what im doing. Thats why i asked . So out of curiousity.. what will the arc do to the sound? What do u suggest to do without drastically changing things?

-aLeX-

[gerald]

just take the "ported" section off and go sealed, that looks close to what sealed should be.

[Lash]

Yes...just seal up the port or else it's gonna sound like poo.


A box that isn't tuned right or dosent have enough port area/port volume will sound TOTALY different from a box that built correctly.
There are calculations you have to use when designing a ported box...you just cant guess.

[8 ur pony]

Personally I've seen good results from caps - bf has 2 in his car, headlights, and dash lights dimmed before he got them - now everything works fine, no more dimming. I have one cap in my car, and I've had no probs with lights dimming (that was in the Sunfire btw - getting the GA tomorrow!!!)

[03BlackGT]

only thing is that i dont care too much for a sealed box sound. It might actually be that i only like it b/c its louder but whatever the case, ive had poor experiece with sealed boxes. What if i opened up the port size to about 2 inches to make it a 2"
x14". I realize it still wont be "tuned" but if it will make a differnece ill just go with that.

[Lash]

Seriously man.....theres waaaaaay more to it than that.

You need at least 60-70 sq.in. of port for those subs. With that curved are it's VERY hard to figure out...especially when your going to be adding glass on top of that which will add to the vent lenght (which will lower the box tuning). to give you an idea..... for a 14" tall port....it would need to be 4-5" wide (so 2-2.5" per port...then you'd need a center divider between them)

They way you used "tuned" isnt the proper meaning. When you tune a box you tune it for a certain freq. The port has to have a certain volume in order to tune the box at the desired freq. For all we know....your box could be tuned at 10hz....or 100 hz....not to mention we dont even know the internal volume of the box. Did you figure that out? You need to know the volume in order to properly calculate the desired tuning frequency.

I dont know what to tell you man. Before steping into something like this you really need to do your homeowrk or else all your hard work isn't going to be worth it. Opening that port up a little is not going to solve your problems.



I'm just trying to help you out before you get too deep into this.

[MantaGreen97]

The curved part shouldn't mess up the porting too badly. I mean your calculated tuning frequency probably wouldn't get distorted too badly I don't think. In fact you can easily calculate the actual port dimensions by simply using a flexible measuring tape (like those used for sewing for example).

But the whole problem is the calculations--you lack them completely! You mention that "Your both right. Its not tuned period".

In that case you shouldn't be putting subs into that box and powering them, period. I said that in a cynical sense but it's true. Putting drivers into a ported box with an unknown tuning frequency is going to cause very bad sound from the subs at best; woofer damage at worst.

As Lash said above, when you do a ported box there are calculations that must be done. As I pointed out, you've done what looks like zero of those calculations, LOL.

The simplest way to make this right... Remove the porting. Calculate your internal gross volume and be sure it is good-to-go for the recommendations/requirements of the drivers you're going to be using. Done. You have a nice looking sealed box. :)

The harder way. Do more research (a lot more than you've done) on building a ported box. Do calculations. Use a program called WinISD. Find it (free dl) and info here:

http://www.linearteam.dk/

It does all the calculations you need for building a ported box in a fairly easy to use application. You can fool with different dimensions and stuff to see what it does to your tuning frequency and frequency response curve from a given driver(s). You will need the complete T/S parameter set for your driver(s) to input into WinISD, however, so get those from the manufacturer's website or product manual.

[gerald]

can a solobaric box work with two subs? cause he can copy the kicker Dual-Comp box. and cant you make the sub think its in a bigger enclosure with poly-fil?

[03BlackGT]

Ok ok ok. The box measuers .94 cubic ft per sub. Each calls for ported box volume: 0.75-1.75 cu. ft. so im good here. I can seem to find the correct parameters for this sub so i cant run WINisd. From here i think im gonna play it by ear. I appreciate the constructive critisism. This is the only way ill learn things like this. Ill show u all what i decide what to go with tommorrow. If i dont like it then ill scrap it and start again ...

-aLex-

[Lash]

.95 is too small for those subs ported. Trust me!! They need around 1.75-2 cubes per sub without sub and port displacement. That box would be perfect for sealed though.

[03BlackGT]

u know a whole lot more than i do but the sub box that came with my sub was made for that sub by alpine. It was a slot ported box and was no where near 2 cubic feet. Its just a lil over 1 cu ft. That box made that sound hit harder than any other set up ive heard with that sub. So im gonna go ahead and leave it. The glass will make it just a lil bigger as well. Thanks ...

-aLeX-

[MantaGreen97]

Originally posted by 03BlackGT
I can seem to find the correct parameters for this sub so i cant run WINisd.

If you can't find the T/S for an Alpine Type-R sub you probably aren't looking hard enough, LOL. A manufacturer as big as Alpine will have them clearly shown in their manuals, and posted on their website or through dl of a .pdf file (probably the manual anyway).

Alpine will also almost certainly have "recommended" enclosures for their subs stating what box volumes you should be using for their sub in each category (sealed, ported, bandpass, free air, etc.). This meaning they've already done the basic work for you, in regards to finding out what boxes the subs will work well in. The recommended enclosures will be simply telling you what cu.ft. volume you need and what tuning frequency to use (in the case of ported boxes).

Since it seems like you've done too little research, and this research is incredibly easy (so it makes me wonder what you're doing, LOL); I decided to look on Alpines site myself.

Within 3 or 4 clicks of going to www.alpine.com I found the product manual for the Type-R sub. This within less than one minute altogether, including the time to dl the pdf manual.

Firstly, the manual has most of the important T/S paramters clearly shown on page 4.

It also shows the recommended enclosures on the same page.

For a sealed box, the recommended enclosure sizes (gross) are:

10" - .65 ft^3
12" - .85 ft^3
15" - 1.75 ft^3

For a ported box:

10" - 1.3 ft^3
12" - 1.7 ft^3
15" - 2.9 ft^3

(Notice the huge change to the 15"--hmm nice work with the 15" Type-R there Alpine :roll2: Anyway, that's besides the point...)

It doesn't state the tuning frequencies for the ported boxes directly but does give the port length, area and displacement (which you can use to calculate the tuning frequency anyway).

In any event, clearly, not even the 10" Type-R should go in a .95 ft^3 gross enclosure--it is indeed too small. For the 12" driver you need nearly 2 ft^3 gross internal volume--your box is about right for one sub, not two!

The interesting point here is it took me all of 3 mins to find this information and it was as easy as going to the address bar on my IE and typing "www.alpine.com" to begin with. Took me about 10-15 minutes to cross-reference the manual and post the information here.

So this wasn't at all difficult. I don't mean any offence at all, but honestly, if you're having trouble finding this information you probably shouldn't be building a sub box to begin with :(

You're either too lazy to even spend 3 minutes to look anything up (and all your time making the box???) or you don't know what you're doing.

I'm not typing this to be mean, I'm typing it so you can save yourself a lot of head/heartache in this project. I'm really trying to help you out here. You seem to have waaay too laissez-faire an attitude about this, IMO. Anyway it's your time/effort/resources wasted if you end up with something sub-par because you refuse to take our comments/suggestions seriously.

[03BlackGT]

lol no offense taken. I never meant for this to go as deep as it was. I was simply looking to make something for the addition to my system so that i can put it to use asap without paying a fortune for a new box. The new amp and sub just came in today. As far as the specs for the sub... i was looking for the 04 model of the type-r which is quit differnet in design but its my fault for not mentioing that. Whether there is a differnece in them at all i wasnt going to scrap everything and start from sratch so i can achieve optimum sound quality. Thats simply not was i was going for from the beginning and what ive been tring to say. If my setup sounds like poo then so be it, but i appreciate the advice for future refrences. I made simple modifications that might bring me closer to standards but i need some of my trunk and i dont mind sacricing quality. I dont mind the critisim but keep in mind that i never claimed to know what im doing. If we can keep it at that ill post some pics later on the progress and u all can rant somemore .. thanx guyz

-aLex-

[03BlackGT]

This isnt final but its might be what it will look like .. not sure if i like it yet. Will be glassed over and the center section removed for the ports.
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