OK, I now know that I would like to build my box 7" X 12 1/4" X 12 1/8".
When you start building the box with 3/4" MDF, do you make the bottom piece bigger on all sides?
For example, if I were to make the bottom (and top) pieces 13 3/4" X 13 1/4" to allow for the 3/4" thickness of the wood on each side, then glue and screw in the 4 sides, how big do I cut the sides?
I'm having trouble picturing this in my head. Would 2 of the sides be 7" X 13 3/4" and the other sides be 7" X 12 1/8"?
That would be adding the 3/4" on 2 sides of 2 of the pieces and not adding to the other 2 peices.
Again, I need the inside dimensions 7" X 12 1/4" X 12 1/8".
THINK THINK My brain is starting to smoke THINK THINK
Replies (10)
uochronos on 11/10/2004 15:41:00
heheh several ways to do this... if it where me i would make the dimensions of the boards this tope board 13" by 12.875". then 2 sides 7" by 12.25 then 2 sides should be 7" by 12.875" ... like i said there are several differnt ways to cut it and get your dimensions. but this way is usualy the way i make my boxes... its easy to put together hehe.
Chronos
PS
any comments or questions feel free to ask.
swez on 11/10/2004 20:35:05
Here's a visual calculator that will help you determine the fit and internal/external dimensions. Don't forget the sub displacement as well.
http://www.bcae1.com/spboxnew2.htm
The box dimensions I got for a 0.6 cf (internal) are as followed. These are the external dimensions of box after assy. That a 10" Infinity sub correct? Sub displacement is probably ~130in^3. (.075ft^3) So, your internal air space should be pretty close to 0.675ft^3.
This box is almost a perfect cube. The size noted below nets a 0.675 ft^3 enclosure internally, (per BCAE 1 calc) using 3/4" thick MDF.
H = 12-1/4" (12.260")
W = 12-1/4" (12.260")
D = 11-1/2" (11.560")
BTW: Your box does not have to be a "perfect" on the button internal measurement. If you are +/- 5% large or small (internally) not a problem. Try to avoid panel cuts that are less than 1/4" increments unless you are "very good" with a table saw. It will only frustrate a beginner to cut a 12-3/16" panel. It can be done... but have to account for saw blade thickness and perfectly square to the blade, guide rail.
Also, if you are planning to do a sealed box. (recommended for first timers) use about 12 oz of polyfil on inner walls and back. Seal all seams internally well to prevent air leaks. The most challenging part of the enclosure, is cutting a good circle for the woofer. Some can do a great job with a sabre saw... but a Roto-Zip w/ compass or router with circle jig attachment are most accurate.
Finally, that 7" deep number mentioned, is way too shallow. Your box is too small. That's only a 0.370 ft^3 box. Try the calculator and you can print out that page with all board orientations and proper panel cuts.
Have fun!
Swez
PS Having a good sander (belt and orbital) will produce a well finished box. A belt sander is great for trimming off mis-fitting panels to flush. A #50-80 grit belt is great for fast material removal. The Orbital sander with 80-120 grit produces a fine board finish.
ttocs on 11/10/2004 20:53:24
I always make the side with the speakers the biggest to allow for more mounting space. Along with this I make the top and bottom the same length, and inset the sides to allow for a stronger, and cleaner box. If you have a good table saw you should not need to sand, I never did.
alanjlamore on 11/10/2004 23:29:09
Thanks guys!!!
Swez, one question about how you got the .37cubic ft. Did you plug it into an equation for outter dimensions?
I multiplied 12.25X12.125X7 and got 1039.71875, then divided by 1728 to get .60168... cu ft. That's what I wanted for inner dimensions.
The only reason I picked 7" is because the other box I have is just over 6" and didn't give enough space for the magnet to "breath".
I'll go to that site tomoro (getting late and my wife's gonna kill me if I stay on the computer any longer).
Thanks again
ryan2 on 11/10/2004 23:38:32
To make it easier on yourself i like to draw out my pieces. It helps alot not only viisually but you catch alot of mistakes and your able to make corrections alot easier
swez on 11/11/2004 10:20:09
Alan,
I used your original numbers: 12.250" x 12.125" x 7.0" as the external dimensions of the box. just plugged them into the calculator, noted board thickness and the numbers came out.
However, if that is your internal dimensions, the box comes out to just as you mentioned... 0.602 cf. Just add sub displacement to the internal number and you internal target is 0.675 cf internally.
Try the calculator and you will not only get an accurate internal/external dimensions, but also a visual look at the box and how the panels are fitted. It even gives you a cut list for the box that you can print out and hang on your wall for a quick reference guide when setting up your panel cuts.
http://www.bcae1.com/spboxnew2.htm
Swez
alanjlamore on 11/11/2004 11:07:10
Thanks Swez, That's what I figgured you did.
I'll try playing with the numbers to get .675 maybe add to the 7" side. I forgot about the sub's displacement *again*.
I remember that site. It's awesome! I even bought the CD from him.
swez on 11/11/2004 20:11:10
If you use these figures as your external values, the internal will be very close to 0.675 cf.
H = 12-1/4" (12.25")
W = 12-1/4" (12.25")
D = 11-1/2" (11.50")
Just for the fun of it, try the calculator. You can adjust (H, W & D) parameters on the slider bar. The calculator will do the rest, show you a picture and give panel cutting dimensions as well. How can you beat that?
Swez
alanjlamore on 11/11/2004 21:39:38
Cool Swez! That saved me a lot of time. I went to that page, but just skimmed past that box with the slider thing in it.
I just tried 11.75 X 12.125 X 12.25 for externals and came up with .678 ft^3
That's a great tool and I immediately put that into my favorites.
I'm still waiting on a reply from Infinity, cause I asked if they took into consideration the displacement of the sub when recomending .6 cu ft.
Thanks again Swez!!
swez on 11/12/2004 12:29:31
Go with what you know. Use the 0.675 cf number as we know there is room for minor alterations and still be well within operational parameters of that sub.
Besides, 0.075cf is such a small amount compared to 0.60 cf... I see no problem going either way. A 0.6 cf or 0.675 cf net is not going to have any major effect on SQ or sub performance.
Swez
When you start building the box with 3/4" MDF, do you make the bottom piece bigger on all sides?
For example, if I were to make the bottom (and top) pieces 13 3/4" X 13 1/4" to allow for the 3/4" thickness of the wood on each side, then glue and screw in the 4 sides, how big do I cut the sides?
I'm having trouble picturing this in my head. Would 2 of the sides be 7" X 13 3/4" and the other sides be 7" X 12 1/8"?
That would be adding the 3/4" on 2 sides of 2 of the pieces and not adding to the other 2 peices.
Again, I need the inside dimensions 7" X 12 1/4" X 12 1/8".
THINK THINK My brain is starting to smoke THINK THINK
Replies (10)
uochronos on 11/10/2004 15:41:00
heheh several ways to do this... if it where me i would make the dimensions of the boards this tope board 13" by 12.875". then 2 sides 7" by 12.25 then 2 sides should be 7" by 12.875" ... like i said there are several differnt ways to cut it and get your dimensions. but this way is usualy the way i make my boxes... its easy to put together hehe.
Chronos
PS
any comments or questions feel free to ask.
swez on 11/10/2004 20:35:05
Here's a visual calculator that will help you determine the fit and internal/external dimensions. Don't forget the sub displacement as well.
http://www.bcae1.com/spboxnew2.htm
The box dimensions I got for a 0.6 cf (internal) are as followed. These are the external dimensions of box after assy. That a 10" Infinity sub correct? Sub displacement is probably ~130in^3. (.075ft^3) So, your internal air space should be pretty close to 0.675ft^3.
This box is almost a perfect cube. The size noted below nets a 0.675 ft^3 enclosure internally, (per BCAE 1 calc) using 3/4" thick MDF.
H = 12-1/4" (12.260")
W = 12-1/4" (12.260")
D = 11-1/2" (11.560")
BTW: Your box does not have to be a "perfect" on the button internal measurement. If you are +/- 5% large or small (internally) not a problem. Try to avoid panel cuts that are less than 1/4" increments unless you are "very good" with a table saw. It will only frustrate a beginner to cut a 12-3/16" panel. It can be done... but have to account for saw blade thickness and perfectly square to the blade, guide rail.
Also, if you are planning to do a sealed box. (recommended for first timers) use about 12 oz of polyfil on inner walls and back. Seal all seams internally well to prevent air leaks. The most challenging part of the enclosure, is cutting a good circle for the woofer. Some can do a great job with a sabre saw... but a Roto-Zip w/ compass or router with circle jig attachment are most accurate.
Finally, that 7" deep number mentioned, is way too shallow. Your box is too small. That's only a 0.370 ft^3 box. Try the calculator and you can print out that page with all board orientations and proper panel cuts.
Have fun!
Swez
PS Having a good sander (belt and orbital) will produce a well finished box. A belt sander is great for trimming off mis-fitting panels to flush. A #50-80 grit belt is great for fast material removal. The Orbital sander with 80-120 grit produces a fine board finish.
ttocs on 11/10/2004 20:53:24
I always make the side with the speakers the biggest to allow for more mounting space. Along with this I make the top and bottom the same length, and inset the sides to allow for a stronger, and cleaner box. If you have a good table saw you should not need to sand, I never did.
alanjlamore on 11/10/2004 23:29:09
Thanks guys!!!
Swez, one question about how you got the .37cubic ft. Did you plug it into an equation for outter dimensions?
I multiplied 12.25X12.125X7 and got 1039.71875, then divided by 1728 to get .60168... cu ft. That's what I wanted for inner dimensions.
The only reason I picked 7" is because the other box I have is just over 6" and didn't give enough space for the magnet to "breath".
I'll go to that site tomoro (getting late and my wife's gonna kill me if I stay on the computer any longer).
Thanks again
ryan2 on 11/10/2004 23:38:32
To make it easier on yourself i like to draw out my pieces. It helps alot not only viisually but you catch alot of mistakes and your able to make corrections alot easier
swez on 11/11/2004 10:20:09
Alan,
I used your original numbers: 12.250" x 12.125" x 7.0" as the external dimensions of the box. just plugged them into the calculator, noted board thickness and the numbers came out.
However, if that is your internal dimensions, the box comes out to just as you mentioned... 0.602 cf. Just add sub displacement to the internal number and you internal target is 0.675 cf internally.
Try the calculator and you will not only get an accurate internal/external dimensions, but also a visual look at the box and how the panels are fitted. It even gives you a cut list for the box that you can print out and hang on your wall for a quick reference guide when setting up your panel cuts.
http://www.bcae1.com/spboxnew2.htm
Swez
alanjlamore on 11/11/2004 11:07:10
Thanks Swez, That's what I figgured you did.
I'll try playing with the numbers to get .675 maybe add to the 7" side. I forgot about the sub's displacement *again*.
I remember that site. It's awesome! I even bought the CD from him.
swez on 11/11/2004 20:11:10
If you use these figures as your external values, the internal will be very close to 0.675 cf.
H = 12-1/4" (12.25")
W = 12-1/4" (12.25")
D = 11-1/2" (11.50")
Just for the fun of it, try the calculator. You can adjust (H, W & D) parameters on the slider bar. The calculator will do the rest, show you a picture and give panel cutting dimensions as well. How can you beat that?
Swez
alanjlamore on 11/11/2004 21:39:38
Cool Swez! That saved me a lot of time. I went to that page, but just skimmed past that box with the slider thing in it.
I just tried 11.75 X 12.125 X 12.25 for externals and came up with .678 ft^3
That's a great tool and I immediately put that into my favorites.
I'm still waiting on a reply from Infinity, cause I asked if they took into consideration the displacement of the sub when recomending .6 cu ft.
Thanks again Swez!!
swez on 11/12/2004 12:29:31
Go with what you know. Use the 0.675 cf number as we know there is room for minor alterations and still be well within operational parameters of that sub.
Besides, 0.075cf is such a small amount compared to 0.60 cf... I see no problem going either way. A 0.6 cf or 0.675 cf net is not going to have any major effect on SQ or sub performance.
Swez
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