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View Full Version : Okay....Here's one for the pros



Hecta G
01-19-2008, 07:44 PM
I have designed to what I think I am ultimately going to use for a sub. It will replace most of the rear deck in my Jetta.

I did a rendering that you can see below that is transparent so that you can see what I have in mind.

Okay, be ya'll start calling every name in the book, let me explain why i want this particular design.

I originally wanted not to even be able to see the woofer i guess that's a 6th order sub, but then thought let's just build it and get it done. Now what lead me to this design is that I wanted to add symmetry to the design so that's why i added the two ports on the top.

Now sealed off one side and placed a tube so that air can travel out of both vents.

If what i have designed will fly what do I need to do to make sure that it will sound decent. My target is 30-35Hz.

Now if this design will not fly what do I need to do or change so that it will. Mind you I would really like to keep the top vents.

Okay, let me have it....http://www.caraudio.com/forum/images/smilies/scared.gif

Here's the rendering....http://sgcalligraphy.com/sub-assembly01.jpg

Random1010
01-19-2008, 08:06 PM
i dont even understand the rendering..

MisterGrubbs
01-19-2008, 08:09 PM
The left side is sealed off from the right. There is a tube leading from the side the sub is on into the sealed side, and air is released through that port over there, as well as the port beside the woofer?

Hecta G
01-19-2008, 08:10 PM
HUH??

:wow:

No unnastan??

MemphisCherokee
01-19-2008, 08:15 PM
hah, you pretty much just stumbled upon an aperiodic bi chamber
what is the internal volume?

Hecta G
01-19-2008, 08:23 PM
Thanks Mista Grubbs for the explicating..

BrianChia
01-19-2008, 08:26 PM
Is it going to be in outer space too? Because sound waves won't travel in a vacuum. :fyi:

jmanpc
01-19-2008, 08:33 PM
Is that supposed to be an ABC box? If so, you're going to have to work on the ports a bit. But it would be a cool install :)

tommyk90
01-19-2008, 08:39 PM
Is that supposed to be an ABC box? If so, you're going to have to work on the ports a bit. But it would be a cool install :)

Hence the post a few above yours...


hah, you pretty much just stumbled upon an aperiodic bi chamber
what is the internal volume?

:)

iamamp3pimp
01-19-2008, 08:42 PM
oops


id seal hat other side off.....impossible to get everything right with any kind of ease

Immacomputer
01-19-2008, 09:10 PM
That's not a design, it's a drawing.

It doesn't look like you actually have ports on top of the enclosure; they look like rectangular holes that only extend about .75" deep.

What you have done with the tube in the center is added a port that will not just pass air into the other chamber unless you play below the frequency that it is tuned to relative to the main chamber. Below this point, the port will short and you will have the two chambers acting like one. This is what happens in an ABC enclosure or a Dual Chambered Tri-Vented enclosure.

If you don't know how to design an enclosure, leave it up to somebody who does. Making a CAD drawing is not the same thing as designing an enclosure just like drawing pictures of jets is no designing a vehicle that can fly.

Hecta G
01-19-2008, 10:44 PM
hah, you pretty much just stumbled upon an aperiodic bi chamber
what is the internal volume?

:eek: HUH??? Isn't that a medical condition of some sort..

Anyway, I will get you the volume, but is there anything that I can read that will explain this to me?

I wish i know more about acoustics my first love is mechanical.

Hecta G
01-19-2008, 10:45 PM
Is it going to be in outer space too? Because sound waves won't travel in a vacuum. :fyi:

LOL!!

Nice designs Brah!

Hecta G
01-19-2008, 10:47 PM
Is that supposed to be an ABC box? If so, you're going to have to work on the ports a bit. But it would be a cool install :)

Thanks for the input bro and have no problem working on the ports, now for the ABC thing.... ya lost me at A..

Scoobydoo
01-19-2008, 10:49 PM
i'm not a pro but i did sleep at a holiday inn express last night

Hecta G
01-19-2008, 10:51 PM
That's not a design, it's a drawing...

If you don't know how to design an enclosure, leave it up to somebody who does. Making a CAD drawing is not the same thing as designing an enclosure just like drawing pictures of jets is no designing a vehicle that can fly.

:crying: ........ NEXT!!!

Hecta G
01-19-2008, 11:43 PM
Okay, i think i have found what i have been looking for so I guess it's time to turn my "drawing" into a "design".

Once i get the model created as to how i will build it i will definately slap some pictures up.

Thanks so much to those of you who were actually helpful and to the rest......

:laugh: ha!

MemphisCherokee
01-20-2008, 12:04 AM
Okay, i think i have found what i have been looking for so I guess it's time to turn my "drawing" into a "design".

Once i get the model created as to how i will build it i will definately slap some pictures up.

Thanks so much to those of you who were actually helpful and to the rest......

:laugh: ha!

check you're PM's bro, i can totally whip sumthin up for ya

Hecta G
01-25-2008, 05:15 PM
okay, i know that i need to get the correct length but will this work???

http://sgcalligraphy.com/jbl2.jpg

Mr Cabinetry
01-25-2008, 06:16 PM
okay, i know that i need to get the correct length but will this work???

http://sgcalligraphy.com/jbl2.jpg

OK, that would work, but, I gotta ask?

If the intent of the design is replace the rear deck with an enclosure, a ported enclosure at that, why not just do that and bag the ABC enclosure design altogether.

Seems to me your making the whole design process more complicated than it needs to be for what you want to achieve for what a regular ported enclosure design will do for ya.

Hecta G
01-25-2008, 07:12 PM
you are correct! I did decide to bag the ABC design. The reason i wanted the ABC was 1) for stealth and 2) stealth enough so the kids wouldn't punch out my cone.

After chatting with Thumper he suggested just place a grill over the cone to protect it. Also to get the desire frequency the box was going to be too big for what I needed.

ngsm13
01-25-2008, 07:20 PM
Porting in the rear deck okay...

You get decent output, and it extends LFE... but you lose a lot of the response/output in the trunk itself.

If you build that box, you'll notice that it sounds pretty good... but you gain a considerable amount of output when you open the trunk lid of your vehicle...

nG

Hecta G
01-26-2008, 12:11 AM
you may need to break it down for me.

BrianChia
01-26-2008, 03:01 AM
Just design a simple ported box. Work out the internal volume, port displacement, port area nad port length, external dimensions, etc. on paper or calculator before you do a CAD drawing of it. Once you actually get a DESIGN down then you can draw it out to help you build it.

Hecta G
01-26-2008, 10:00 AM
i use the cad drawing to visualize what i want using rough numbers. The program i use takes less than 5 minutes to create a box and less than 30 seconds to change dimensions. It will also give volume. So that is why i put it on cad.

Also it's what i do for a living

amartin_72
01-27-2008, 09:39 PM
vw owner, check

req
01-27-2008, 10:22 PM
why not just go IB and cut some holes in the rear deck, mount a baffle to it, mount subs to baffle, fold up the rear seats and call it a day?

you could easily fit two twelves in the rear deck of a jetta even 3 tens. with that kind of cone area you will make up for the loss of an enclosure and gain the extra SQ while you are at it.

get a few ID10's and throw em up there and pump 800w to em.

Hecta G
01-27-2008, 10:33 PM
Actually I think I may have thought of something along those lines this weekend because I want to get this thing moving.

The thought did occur to me, hmmmmm cutting up the rear deck. Now I just want to minimize the cutting.

So, I think I may make a split box, one part on top and the rest under the rear deck. Cutting just enough of the rear deck to allow the sub to drop in.

I will need to get the angles right so that I can put a flang to join the two. I can feel some eye-rolling out there so I will make sure to have everything sealed up nice and fully documented.

kinda getting excited, nervous... i think i need to go hurl...:suicide:

req
01-28-2008, 05:48 PM
dude no. just make a board that attaches to the rear deck - as big as possible. then take it out and cut your speaker holes. mount speakers from the bottom. and then cut small holes in the rear deck to open the cones to the interior of the jetta. this is in a BMW M3. similar idea.

http://img.photobucket.com/albums/v642/rcurley55/new%20install/IMG_1344.jpg
http://img.photobucket.com/albums/v642/rcurley55/new%20install/IMG_1347.jpg
http://img.photobucket.com/albums/v642/rcurley55/new%20install/IMG_1454.jpg

easy as that. just seal up around the edges of the wood with some silicone between it and the metal, cut 4 8" holes square if you want em to be, does not really matter.

and you will be done. easy as that. stop making this harder than it should be.

Hecta G
01-28-2008, 05:59 PM
thanks for the idea but the reason that I am making it harder is because I am looking more for a stealth solution.

Although in a pinch I may have to go this way.

I had a real nice setup in my Sentra where you couldn't see anything and if you looked close you could find the amps but would never know you were staring at the sub.

It was a Cerwin Vega 10" ported firing into the back seat in which the seat was acting as a passive radiator nice lows.

BrianChia
01-28-2008, 06:16 PM
You had a passive seat radiator? Nice.

Hecta G
01-28-2008, 07:15 PM
yeah, it was kinda crazy and definately unplanned but was nice side effect of what i was doing at the time. I will post the in car readings later tonight if i can find them.