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The owner of that website is a member here named Ricci. That cabinet is a good size for the 18" SI.
 

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Discussion Starter · #4 ·
That build i linked to is it double Mdf boards in the front on that mesurement.

22*22*22 inch box.

I think to take a smaller depth on the box.

500 mm = 19.68 inches

19 mm thick mdf board to build with. Double front boards with one inside and one outer
board so it seeing out like one board on the outside of the box.

What do you recommend on width and hight to get a good box size.
 

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Its all about volume. SO 20x20x19.5= 97.6liters. This is with double walls on all sides. If you use single layer sides then there is a bit more room.

But even this size is perfectly fine for the 18".
 

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Discussion Starter · #6 ·
It´s only in the front i plan to have double boards on 19 mm Mdf.

What internal volume is to recommend ??

I have write up a box on.

600 mm width = 23.62 inches , 600 mm hight = 23.62 inches and 500 mm deep = 19.68 inches.

139.92 liters in internal volume.

Then you take away 7 liters for de driver and some for internal reinforcement.

Or is this for big in volume ??
 

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113 liters sealed recommended. SO you could do a 600x600x500 but use double walls on all walls and be pretty close to recommended. I would either double thickness on all walls and simple bracing or use single layer walls but heavily braced. This sub will definitely flex the walls if not. And the more your walls flex the more SPL you lose.

So 95-120liters and your fine. You are not going to notice a huge difference in 10liters here or there. Smaller cabinets add more mechanical protection and lose some efficiency in the lower end. BUT with a 45mm Mech Xmax you will be fine with this driver in any of the sizes using recommended power.
 

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Discussion Starter · #8 ·
On the box i linked to in the beginning.

Is that box 118.93 liters internal and i hope they have counted away the woofer and the bracing in
that volume.

If i take 22 mm or 25 mm Mdf boards is this enough to have single walls ??

Than i think to brace the box on this way.

http://www.minhembio.com/forum/index.php?showtopic=309224

Check in number 15# on the pitchures.

I have changed the dimensions on the box now.

22 mm Mdf board. 590 mm width , 590 mm hight, 500 mm depth.

Internal volume are 126.4 liters - 7 liters for woofer - 2 liters for bracing = 117.4 liters.


25 mm Mdf bord. 595 mm width , 595 mm hight , 500 mm depth.

Internal volume are 126.2 liters - 7 liters for woofer - 2.3 liters bracing = 116.9 liters.


How much polyfill is recommended to this box sizes ??
 

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Discussion Starter · #9 ·
My goal is to came as near as possible as the test box that i linked to in this thread.

Should i go with.

590*590*500 mm = 129.38 liter internal and external 174 liters

585*585*500 mm= 127 liters internal and external 171.1 liters


The test box was 558.5, 22 inch *558.5, 22 inch *558.5, 22 inch = external 174.48 liters and 118.93 liters internal.

I`m not shoure how much place in liters the bracing are taken in the box.

The woofer take 7 liters.
 

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I am pretty certain that box was about 115liters internal. SO your dimensions of either size would work. You will still need bracing so depending on which style of bracing you go with you can determine the volume to choose.

I could not look at your links you had of the bracing so I dont know how much room you will use with bracing. BUT you can use EVC (enclosure volume calculator) here on HTS and determine how much room you will be using with your bracing. Try and brace every 20cm if possible.
 

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Discussion Starter · #11 ·
I have checked on that guide and that are Bracing "Optional Square" with 4 cut outs + one rectangular bracing with only the frame left for all sides that i will have closest to the woofer.

What is recommended to left to get it strong ??
 

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Bracing with only the four cut outs will give you the most strength and rigidity. However, the strength comes from how wide the frame is, so a single cutout frame with a wide frame will likely be just as good as a frame with four cutouts.
 

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Discussion Starter · #13 ·
Bracing with only the four cut outs will give you the most strength and rigidity. However, the strength comes from how wide the frame is, so a single cutout frame with a wide frame will likely be just as good as a frame with four cutouts.
That i have thougt is to have a frame bracing in the front and a bit back in the box bracing with
four cut outs. So total 2 bracings in each box.

How much is recommended to leave to get it solid and strong with minimal of movement of the sides.
 

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Discussion Starter · #14 ·
I am pretty certain that box was about 115liters internal. SO your dimensions of either size would work. You will still need bracing so depending on which style of bracing you go with you can determine the volume to choose.

I could not look at your links you had of the bracing so I dont know how much room you will use with bracing. BUT you can use EVC (enclosure volume calculator) here on HTS and determine how much room you will be using with your bracing. Try and brace every 20cm if possible.
I have used that calculator you recommended and understod it.

I will use 1 bracing with four cut outs as sqaures and 1 bracing with a frame and a round woofer hole with frames around a little bit of straight frame to to round bracing frame.

Have calculated that when i take away woofer + bracing the volume will be 115.45 liters.

All frame parts will be 30 mm = 1.18 inches is this enough to be solid ??
 

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All frame parts will be 30 mm = 1.18 inches is this enough to be solid ??
Are you talking 30mm in thickness of the bracing or the width of the frame? The width of the frame is what gives the most rigidity (though obviously too thin of material wouldn't give you much strength).
 

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Discussion Starter · #16 ·
Are you talking 30mm in thickness of the bracing or the width of the frame? The width of the frame is what gives the most rigidity (though obviously too thin of material wouldn't give you much strength).
It is the width of the frame im talking about. This will be 30 mm.

The material will be 22 mm mdf in thickness.
 

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I think you shouldn't have any problems with that. You will have the least amount of flexing of the panels with the braces centered at the midpoints of each side. Sometimes this isn't possible and you will have to offset the brace. That shouldn't be a problem.
 

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Discussion Starter · #18 ·
What sorts of filling are you recommending in a Sealed box and how much in gram ??

In Sweden i now that alot of people uses building isolation as filling for it´s low cost.
 

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You're going to want to look for polyester fiberfill - that's what I see most often in the builds here. You can find it in a variety of places and I would expect you could find it in a fabric store there in Sweden or you can tear apart a pillow that is stuffed with it.

As for the amount, I've heard various amounts recommended from 1/2 lb polyfil per cubic foot of enclosure volume (450g/28.3l for you metric folks) up to 1lb/cuft of volume (900g/56.6l).
 
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