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35thStangGT
12-22-2011, 10:24 AM
Okay this might get alittle long so bare with me PLEASE.
Im not rich, and im young so I would like to know how to build boxes, because everyone around me at a shop completely **** at it.
Okay what I have is a 1999 Mustang GT coupe. My box diameters are 31" x 31" x 13.25", which gives me a internal 5.068 cu ft box with 3/4" MDF after displacements of 3 12s. Now the tuning part.. Im tuning for 30 Hz. Running a square port of 11.75" x 3.5" and the length is 20.93"? Am I right so far?
Also the subs will be firing upwards towards the deck lid.. My ports will be going out the trunk. Im worried the port isnt big enough? Please get back to me! :/
Should I go with round ports?
If so how many? and what size? Sorry just trying to learn lol xD

35thStangGT
12-22-2011, 02:56 PM
Gives me 1.844 cu ft per section, with a square port 6"x 2" at 30 hz.
Port length is, 18.1"
Does that sound right? and will 3 VVX Skars like that? :)
Edit: Took out the dividers.
http://img28.imageshack.us/img28/4006/subwooferboxstang.jpg (http://imageshack.us/photo/my-images/28/subwooferboxstang.jpg/)

pro-rabbit
12-22-2011, 03:00 PM
What are you trying to do? Why make 3 separate chambers?

35thStangGT
12-22-2011, 03:09 PM
Because I heard that if one sub blows, without a divider it will blow the others as well.
And if u havent seen the pic i posted yet, please check that out. I havent put the ports in yet but thats with autocad and my info is from bbp6.
do i need dividers? lol :/

35thStangGT
12-23-2011, 09:41 AM
anyone?

Bettr n' Revrse
12-23-2011, 09:48 AM
Because I heard that if one sub blows, without a divider it will blow the others as well.
And if u havent seen the pic i posted yet, please check that out. I havent put the ports in yet but thats with autocad and my info is from bbp6.
do i need dividers? lol :/

Hahaha who told you that???

35thStangGT
12-23-2011, 10:21 AM
Google :D
So I dont need dividers??? :))

35thStangGT
12-23-2011, 12:38 PM
Edited top post! bump!

pro-rabbit
12-23-2011, 12:42 PM
You have to take port displacement into account when designing the enclosure. If you do not the tuning will be off as will the enclosure.

With your limited space, I would look into doing 2 12s in a well designed/built enclosure. You will more then likely have better results.

Unless you plan to run a fully external port then you might be able to squeeze 3 12s...but not looking to good though.

35thStangGT
12-23-2011, 12:43 PM
Im using BBP6, I think it takes off for port displacement.

pro-rabbit
12-23-2011, 12:45 PM
You have 5.9 gross with no bracing, sub/port displacements or anything else adjusted into it.

35thStangGT
12-23-2011, 12:51 PM
well 3 sub displacements looks like .324 cu ft?
and the port displacement at 11.25 x 3 is .598 cu ft.
That leaves me with 4.995 cu ft.

IonRL205
12-23-2011, 12:51 PM
Pro Rabbit makes some pretty good boxes. He knows what he's talking about. You'll be better off with 2 properly ported 12s than 3 suffocated 12s.


well 3 sub displacements looks like .324 cu ft?
and the port displacement at 11.25 x 3 is .598 cu ft.
That leaves me with 4.995 cu ft.

That is too small for three 12s. Alot people use around 4.5 to 5 cubes for just a pair of 12s.

pro-rabbit
12-23-2011, 12:53 PM
well 3 sub displacements looks like .324 cu ft?
and the port displacement at 11.25 x 3 is .598 cu ft.
That leaves me with 4.995 cu ft.

what subs, and what are the dims of the port? 11.25 x 3 is not the whole thing you have a number missing lol.


EDIT look at your first post to find the length of the port 11.75 x 3.5 x 21(ish)

That has a port area of 41.125 which is pretty small for a 5ft3 enclosure.

35thStangGT
12-23-2011, 12:54 PM
I dont think im suffocating them.
Skar VVX 12s

You need the LV?
11.25" x 3"
LV= 18.09"

And I will use aero ports if I have to?

IonRL205
12-23-2011, 12:54 PM
what subs, and what are the dims of the port? 11.25 x 3 is not the whole thing you have a number missing lol.

20.93" is the other dimension, and he's using Skar VVX 12s


I dont think im suffocating them.

You would want at least 6 cubes imo after sub/port displacement for three 12s. Mustangs have very small trunks, you're not going to get too much out of it unless you build the box inside of it.

pro-rabbit
12-23-2011, 12:57 PM
You can run 3 skars in a 5ft3 enclosure per their reps anyway.(I won't do it in most cases)

The port area is very small and limited, I have not done any graphing or any thing other then looking his numbers though.

35thStangGT
12-23-2011, 01:03 PM
Well it looks like space is an issue. Would I benefit from round ports?
If I built the box inside the trunk I could easily get 6+ cu ft.
With a single 5" aero port im looking at 5.5 cu ft? Lol. Why is this **** so hard? Or maybe im just dumb.

If I did build the box inside the car. I would take out the spare and use that bigass for more space. That hole is huge, and I can probably get another cu ft or so if itll help!

pro-rabbit
12-23-2011, 01:10 PM
If you built it in the car you would/should have enough room to do a slot port if you wish. All though if you do not have a decent built method or quality you may want to go with a different method, it is a pita to build in a trunk...

IonRL205
12-23-2011, 01:13 PM
I really think your best bet is to go with fewer subs; a pair of 12s properly ported on 3k will definitely do work.

Pro-Rabbit knows his ****, I got a box from him and was definitely impressed. If you want box advice, I'd definitely listen to him.

35thStangGT
12-23-2011, 01:16 PM
Well Ive built like 5 or 6 boxes(LMFAO), been around building all my life. (Im 18 btw lol) Im not the best, but I have trust in my work you could say. Only problem I see is, if one of the subs blow, its gonna be a pain in the *** to get the sub out. And yes mustang trunks are SMALL!

What would you suggest pro_rabbit?

IonRL205
12-23-2011, 01:17 PM
Well Ive built like 5 or 6 boxes(LMFAO), been around building all my life. (Im 18 btw lol) Im not the best, but I have trust in my work you could say. Only problem I see is, if one of the subs blow, its gonna be a pain in the *** to get the sub out. And yes mustang trunks are SMALL!

Well the subs shouldn't blow to begin with unless you don't know what you're doing.

pro-rabbit
12-23-2011, 01:19 PM
Well Ive built like 5 or 6 boxes(LMFAO), been around building all my life. (Im 18 btw lol) Im not the best, but I have trust in my work you could say. Only problem I see is, if one of the subs blow, its gonna be a pain in the *** to get the sub out. And yes mustang trunks are SMALL!

What would you suggest pro_rabbit?

I would suggest building an enclosure for 2 12s and see how it performs for you. If it is not enough then plan out an enclosure for 3 12s built in the trunk.

35thStangGT
12-23-2011, 01:19 PM
Well the subs shouldn't blow to begin with unless you don't know what you're doing.

Your talking to a guy who's only owned kicker L7s lol. See my point now? :D

Imtjnotu
12-23-2011, 01:20 PM
i would go with 2 of the skars with that space....ive owned a pair

35thStangGT
12-23-2011, 01:21 PM
Im scared if I run 2 12s my friend is gonna walk all over me with his 2 15" L7s on 3k rms. But I seen his box for them, its suffocating them badly, but it bangs!
and im scared if i run 2 12s on 3k it wont last long, Lol.

pro-rabbit
12-23-2011, 01:23 PM
Im scared if I run 2 12s my friend is gonna walk all over me with his 2 15" L7s on 3k rms. But I seen his box for them, its suffocating them badly, but it bangs!
and im scared if i run 2 12s on 3k it wont last long, Lol.

Odds are if they have a hatch or SUV you will not achieve what they are doing with out a ton of work. If you are only doing this to one up your friends plan to spend a lot of money and time to do so. Not to mention it is all the wrong reasons to do this in the first place.

IonRL205
12-23-2011, 01:27 PM
Im scared if I run 2 12s my friend is gonna walk all over me with his 2 15" L7s on 3k rms. But I seen his box for them, its suffocating them badly, but it bangs!
and im scared if i run 2 12s on 3k it wont last long, Lol.

Well with a properly ported box, you may end up being louder than him on 3k with a pair of 12s if his box is garbage. And if you get two 12s that handle 3k then they will last, but if you overpower them too much then they won't last. I think you need to do a little more research before you start doing any kind of build.

35thStangGT
12-23-2011, 01:29 PM
Dont get me wrong, I miss my subs. Thats why I want to do this build. And to prove to my friend that round subs can get just as loud as squares. His is in a 97 Toyota Camry btw.
I will research into it, I dont have to run 3000w, but thats my target wattage for my build.

IonRL205
12-23-2011, 01:32 PM
Dont get me wrong, I miss my subs. Thats why I want to do this build. And to prove to my friend that round subs can get just as loud as squares. His is in a 97 Toyota Camry btw.

Well if you want to do that, then you would want to use 15s, because a properly ported L7 15 should get louder than a properly ported 12 on the same power just due to the extra cone area. You're trying to teach your friend something, and that's good, but you're going at it the wrong way.

I just don't see you getting louder than him with 12s unless his box is just truly garbage. Do you know the specs of his box? Is it custom or a kicker pre fab? Sealed or ported?

35thStangGT
12-23-2011, 01:38 PM
okay well, Im gonna get accurate measurements of my trunk, and the only reason why Im not paying someone to do this is because I find car audio fun, and its all a learning experience. See exactly how much cu. ft I have to work with. I cant wait to get subs back in my car. If 2 12s will get loud, and make my friends say "WTF" It will put a smile on my face.

IonRL205
12-23-2011, 01:40 PM
okay well, Im gonna get accurate measurements of my trunk, and the only reason why Im not paying someone to do this is because I find car audio fun, and its all a learning experience. See exactly how much cu. ft I have to work with. I cant wait to get subs back in my car. If 2 12s will get loud, and make my friends say "WTF" It will put a smile on my face.

Two 12s can definitely get loud, even single 12 setups can get loud. Its all in the box.

35thStangGT
12-23-2011, 01:41 PM
Mind if i PM you for future info?

Imtjnotu
12-23-2011, 01:44 PM
good words ionrl

IonRL205
12-23-2011, 02:33 PM
Mind if i PM you for future info?

I don't mind, I'm down to help whenever I can

Here's a single 12 setup on 3krms. Definitely doing work


http://www.youtube.com/watch?v=gTC_io-OMtE

Dual 12 setup on SAZ3500D .5 ohm


http://www.youtube.com/watch?v=hZllM5vTR_M