Final box design critque for 12inch Magnum d2

[allConfused 0]

Key

Box Width( not shown in pic) is 18.5in external, and 17in inside box

Blue line at top of box: aprox 5.83 in.

Red line at top of box: 6 in.

Blue line at bottom of box: aprox 10.16 in.

Red line at bottom of box: 10 in.

Blue line on inner left wall: 18 in.

Bright Green on slanted face: 12 in ( aprox sub mounting space)

Connected slanted red lines on slanted face: 6in per 2 lines

Top slanted blue line from floor to slanted face (Brace) 8 in.

Bottom slanted blue line from base to slanted face(brace) 5 10/16 in.

Those 2 slanted blue lines i just mentioned are 1 piece of wood. its just the measurement of the top of it and bottom of it.

Red line connected to top and bottom slanted blue lines: 2 inch.

dimensions for thickness of that brace is 2inx1.5in

The Black line from top to bottom inside box is 18in. this is a sqaure brace touching all 4 sides of the box. its 1.5 in think as stated on paper by 2 inches thick.

Bright teal line on the box inside sub box: 8 inches( represents where the sub maget should end)

Light teal lines going into box in sub box: 6.75 inches( The end of this line is where the sub would end if the sub where a box)

The height of the box outside is 19.5 in.

The depth of the bottom box wall outside is 11.5 in.

the depth of top outside box wall is aprox 6.83 in.

The slanted front wall outside box is aprox 19.97 in.

total CF after all bracing, drivers, and slanted wall, except the braces from bottom of box to slanted wall is aprox 1.286CF

ill have the slanted wall bracing figured out soon. i expect it wont be greater than .03CF

with this design i figure after polyfill i will be around 1.3-1.32CF? ?

post all comments and sugjestions please thanks!

if you got any questions lemme know

[I8apony19 0]

I LOVE your drawing..and it is FAR more detailed than ANY of us would have done...but it's NOT really that complicated....

Don't worry about bracing...you won't need to worry about flexing in that install....

Try and get your box size a bit bigger IF possible (1.5 cubes)...or stuff it with a good amount of polyfill

Pretty much just find the dimensions for all 6 sides, account for your slanted baffle...and slap that puppy together!

3/4" mdf, some good ol' glue, some good 2" wood screws..and seal that puppy from the inside with silicone and you're good to go!

OH YEAH...PRE DRILL your holes

Edited March 5, 2004 by I8apony19

[allConfused 0]

yeah i wanted to go all out and get it perfect the first time. why do you think i should bump it to 1.5 cubes?

and i was thinking of skipping srews all together and using the strongest grade liquid nails for wood.

for mounting the sub to the box i was gunna use bolts with locking nuts on the other und so i dont ever strip the wood or anything and i was gunna use rubber 0-rings around the back and front of the box on the bolts to ensure that airtight mount.

by the way if i got an airtight fit technically i shouldnt be able to push in my cone at all right?

and he nick you told me to put a layer of fiberlass insulation around the walls. its ok for that to touch the sub right? becuase as you can see in he picture at the top of the bright teal line the magnet is only 1.7 inches away from the wall and it possible the insulation might stick out that far and touch it. if its bad to touch ill just cut a small part out of the insulation.

[Electrodynamic 2]

Fiberglas or polyfil can touch the speaker without any problem. Was it you or someone else who asked this already in another post?

If you don't screw the box together there is a good chance that the Magnum will fracture a joint. We've had that happen with two enclosures so far, so like Clarke said, use screws.

...and you will still be able to push on the cone if the enclosure is completely sealed.

[allConfused 0]

yes but i asked about polyfil wasnt sure if the fiberglass insulation could touch.

i guess ill go for screws if i must though. how many should i have per side

[I8apony19 0]

yes but i asked about polyfil wasnt sure if the fiberglass insulation could touch.

i guess ill go for screws if i must though. how many should i have per side

there is no such thing as a "sufficient" amount of screws on a box..I've seen boxes with HUNDREDS of screws..

If it's a relatively smaller box..I'd say every 3-4" would be just fine to secure, nice, TIGHT bond...

T-Nuts are always good...don't want that sub fallin' out at all...I think Strong I bumpin can attest to that!

PUT IT TOGETHER!!

PICS PICS!

[Tirefryr 1,742]

Actually if you use wood glue, it will bond the joint together and that will actually be stronger than the wood itself. The wood will break before the bond will fail. I use screws as a clamp only. Somtimes I remove them after the glue has cured, other times I just cover the heads with wood putty. Either way, if you build it CORRECTLY, you should have no problems with any driver tearing the enclosure apart.

[I8apony19 0]

Actually if you use wood glue, it will bond the joint together and that will actually be stronger than the wood itself. The wood will break before the bond will fail. I use screws as a clamp only. Somtimes I remove them after the glue has cured, other times I just cover the heads with wood putty. Either way, if you build it CORRECTLY, you should have no problems with any driver tearing the enclosure apart.

BINGO..that's exactly what I do!.....DEFINITELY use wood glue...and screws are MUST too..

[Tirefryr 1,742]

OH YEAH...PRE DRILL your holes

BINGO..that's exactly what I do!.....DEFINITELY use wood glue...and screws are MUST too..

How can you do that when you don't even own a drill???!!!

[allConfused 0]

are you serious? i thought the top grade liquid nails was about as good as you could get.

but wood glue is better?

[Electrodynamic 2]

Yes, wood glue is better. Like Tirefryr said, the wood around the joint will actually break before the joint breaks with wood glue. I didn't believe it myself until we experimented with it a while back.

[I8apony19 0]

OH YEAH...PRE DRILL your holes

BINGO..that's exactly what I do!.....DEFINITELY use wood glue...and screws are MUST too..

How can you do that when you don't even own a drill???!!!

For the record....all of my pre-drilling as taken place at home...or in Scotty's shop...

And not having ANY tools around just flat out sucks....I can't work on my car AT ALL...

I feel pretty silly using a Leatherman to screw my speaker connections...

[allConfused 0]

man maybe the wood glue i used last time sucked then. is there different strengths of wood glue?

[Jalla 0]

Polyurethane wood glue is excellent for use with MDF.

It works like this: dissolves the surface of the two adjoining boards somewhat, eats into the fabric of the MDF and hardens deep inside, not just on the surface.

The stuff sticks like crazy, and also expands when hardening, thus ensuring a totally sealed box. No silicone needed. Use tons of it as the MDF sucks it up!

Another good tip is to use clamps when srewing in the screws. Even if you predrill, the MDF is pretty brittle, and cracks very easily.

This especially applies when attaching the front plate, as it allready has a hole in it.

Here's a Norwegian review of a home theatre sub kit where this glue was used.

Edited March 9, 2004 by Jalla

[allConfused 0]

since fiberglass insulation is a denser material than polyfill will it take up any internal volume?

[Electrodynamic 2]

No. It, like polyfil, effectively adds volume to the enclosure.

[allConfused 0]

uh i just came across a person saying this in a thread i was reading in sound domain.

its in regards to fiberglass insulation.

"I used it once, BIG MISTAKE!! The fibers got into my VC and the motor strucure of my 12W1 and f*cked it up, now it pops and sounds bad with anymore than 50wts. Don't do it, use pillow stuffing."

[allConfused 0]

i know i posted this befor but no one replied to it. anyone know of any nice looking "STRONG" grills for the magnum subs i could buy. 12 inch version of course. i wanna make sure at full excursion the sub wont touch the grill.

i wanna make sure dumb @$$'s cant ruin my subs by dropping a backpack or something on them.

[Electrodynamic 2]

Unless the person didn't attach the fiberglas insulation to the walls (like I have suggested), it might go up in the pole...but so could polyfil. Take what you heard however you want.

There are no grilles that I know of that will be compliant with a Magnum's amount of travel.