I need to build a box for 2 12" subwoofers. I'm not experienced with CAD, so I need someone to help me design it. I am looking for .75 cu ft per sub. If anyone could design one, it would help me out a lot. It's going to be in a 2002 Ford Escape so the box size doesn't really matter that much.
Thanks in advance,
Escape
Replies (9)
uochronos on 08/27/2004 15:58:53
the boxes dimensions need to be right around 8 deep by 27.75 long and 13 wide. i'm sure one of are CAD guys here can whip up a diagram but thats what the dimension need to be to get a .75 box.
btw what subs are these and do you want this box to be .75 after sub displacement or before. those specs i gave you are before sub displacement.
hope this helps
Chronos
swez on 08/27/2004 16:29:32
There is a basic box designer and calculator you can use to design and print out your own enclosure specs. The calculator and illustrator is located here:
http://www.bcae1.com/spboxnew2.htm
Swez
PS Just make sure you allow for sub displacement and the "H" & "W" are 2.0" (min) larger than diameter of the sub.
Escape on 08/27/2004 17:08:38
The subs I am going to use are the MA Audio MA121XQ 12" subs.
What exactly is sub displacement? I am not quite sure I understand it.
Escape
uochronos on 08/27/2004 17:32:46
ok say the sub needs a 1cibic foot internal air space... well thats a 12" by 12" by 12" box right? well the sub takes up a certain amount of space lets say .25cubic feet thats justb a random number.... which means to get a 1cubic foot internal air space you would need to add .25cubic feet to the box. since the sub is taking up that much room.
Geezer on 08/27/2004 18:03:57
There is a program that can be downloaded for free, WinISD, that is very useful in box designing; sealed, ported, and bandpass. It doesn't determine the correct volume per T/S paramenters, but it does graph the results of varying box volumes and port dimentions. (It has a database of hundreds of sub specs built in and allows for user defined parameters if your sub is not listed). There's also a volume calculator for different shaped boxes. If you're interested, do a Web search for WinISD and it'll come up.
swez on 08/28/2004 10:45:12
WinISD is a very good program, if you have the time to learn it. More for advanced users than a beginner. It's not something you can do in 1 hour and get great results the first time out.
The bce1 calulator is very easy and in 30 minutes, you'll have a good idea what is needed and a diagram you can print out with cutting dimensions as well.
Swez
Wealot53 on 08/29/2004 02:19:18
Width X Height X Depth DIVIDED by 1728= cfas
the basic formula
swez on 08/29/2004 08:03:27
Yep, that's the formula we use with a twist...
H x W x D = gross cf external. Then, we subtract wood thickness and sub displacement to get net internal volume.
The bce1 calculator does all this for you. Just plunk in the numbers (slider bars for H,W & D) and it spits out a box shape that you can adjust to fit your needs. Very easy to use and you can print out a copy to work from as a blue print. (a cut sheet if you will)
BTW, if your sub target is 1.5 cf, don't fret if you come up a few % off either larger or smaller. It will be fine. Sure beats having to measure cuts to 1/16" scale to get the exact number. This is less than the thickness of a typical saw blade.
Swez
http://www.bcae1.com/spboxnew2.htm
swez on 08/29/2004 08:21:49
Cannot find that sub model number noted... is that an older sub model? It did not come up on MA search engine. MA121XQ ???
Ahhh, 2004 model found at Parts Express... still no info on sub displacement figures. Hopefully it will be on your install manual sheets. Looks like this sub is designed for porting too. Don't forget to subtract port displacements as well.
Swez
Thanks in advance,
Escape
Replies (9)
uochronos on 08/27/2004 15:58:53
the boxes dimensions need to be right around 8 deep by 27.75 long and 13 wide. i'm sure one of are CAD guys here can whip up a diagram but thats what the dimension need to be to get a .75 box.
btw what subs are these and do you want this box to be .75 after sub displacement or before. those specs i gave you are before sub displacement.
hope this helps
Chronos
swez on 08/27/2004 16:29:32
There is a basic box designer and calculator you can use to design and print out your own enclosure specs. The calculator and illustrator is located here:
http://www.bcae1.com/spboxnew2.htm
Swez
PS Just make sure you allow for sub displacement and the "H" & "W" are 2.0" (min) larger than diameter of the sub.
Escape on 08/27/2004 17:08:38
The subs I am going to use are the MA Audio MA121XQ 12" subs.
What exactly is sub displacement? I am not quite sure I understand it.
Escape
uochronos on 08/27/2004 17:32:46
ok say the sub needs a 1cibic foot internal air space... well thats a 12" by 12" by 12" box right? well the sub takes up a certain amount of space lets say .25cubic feet thats justb a random number.... which means to get a 1cubic foot internal air space you would need to add .25cubic feet to the box. since the sub is taking up that much room.
Geezer on 08/27/2004 18:03:57
There is a program that can be downloaded for free, WinISD, that is very useful in box designing; sealed, ported, and bandpass. It doesn't determine the correct volume per T/S paramenters, but it does graph the results of varying box volumes and port dimentions. (It has a database of hundreds of sub specs built in and allows for user defined parameters if your sub is not listed). There's also a volume calculator for different shaped boxes. If you're interested, do a Web search for WinISD and it'll come up.
swez on 08/28/2004 10:45:12
WinISD is a very good program, if you have the time to learn it. More for advanced users than a beginner. It's not something you can do in 1 hour and get great results the first time out.
The bce1 calulator is very easy and in 30 minutes, you'll have a good idea what is needed and a diagram you can print out with cutting dimensions as well.
Swez
Wealot53 on 08/29/2004 02:19:18
Width X Height X Depth DIVIDED by 1728= cfas
the basic formula
swez on 08/29/2004 08:03:27
Yep, that's the formula we use with a twist...
H x W x D = gross cf external. Then, we subtract wood thickness and sub displacement to get net internal volume.
The bce1 calculator does all this for you. Just plunk in the numbers (slider bars for H,W & D) and it spits out a box shape that you can adjust to fit your needs. Very easy to use and you can print out a copy to work from as a blue print. (a cut sheet if you will)
BTW, if your sub target is 1.5 cf, don't fret if you come up a few % off either larger or smaller. It will be fine. Sure beats having to measure cuts to 1/16" scale to get the exact number. This is less than the thickness of a typical saw blade.
Swez
http://www.bcae1.com/spboxnew2.htm
swez on 08/29/2004 08:21:49
Cannot find that sub model number noted... is that an older sub model? It did not come up on MA search engine. MA121XQ ???
Ahhh, 2004 model found at Parts Express... still no info on sub displacement figures. Hopefully it will be on your install manual sheets. Looks like this sub is designed for porting too. Don't forget to subtract port displacements as well.
Swez
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