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View Full Version : Planning to build a box...what materials?



Frankensuby
11-16-2006, 09:31 PM
I've got a Home Depot close by.

Now I know the basics: 1.5 inch screws, a drill, wood glue, possibly some high pressure silicone sealant of some sort, 3M #90 glue, and carpeting. What i want to know is what type of wood to use.

I can get ahold of 3/4" MDF, but not 1". I want to overbuild this box so that I can put something crazy in it later on, plus, it'll fit specifically to my Impreza. I'm putting in a PG Xenon 10" for now, but who knows what I'll put in later ;)

Is there a better wood than MDF to build a box out of? If so, what would you suggest? The denser the better.

~Levi

azimuth
11-16-2006, 09:32 PM
I've got a Home Depot close by.

Now I know the basics: 1.5 inch screws, a drill, wood glue, possibly some high pressure silicone sealant of some sort, 3M #90 glue, and carpeting. What i want to know is what type of wood to use.

I can get ahold of 3/4" MDF, but not 1". I want to overbuild this box so that I can put something crazy in it later on, plus, it'll fit specifically to my Impreza. I'm putting in a PG Xenon 10" for now, but who knows what I'll put in later ;)

Is there a better wood than MDF to build a box out of? If so, what would you suggest? The denser the better.

~Levi

medium density fiberboard. 5/8 or 3/4. what could be that much better?

GrnEydDvl
11-16-2006, 09:35 PM
3/4 mdf. It is the best balance of weight, price, structural integrity, and acoustics. There is really no need for anything else in a car.

You can use 5/8 in a pinch.

Frankensuby
11-16-2006, 09:35 PM
medium density fiberboard. 5/8 or 3/4

I know I can use that, but I do not like the stuff. Working with it in the past, it likes to crumble out when being worked with. I was thinking more along the lines of ply wood of some sort, something stronger with atleast the same density.

Is that feasible?

~Levi

azimuth
11-16-2006, 09:38 PM
I know I can use that, but I do not like the stuff. Working with it in the past, it likes to crumble out when being worked with. I was thinking more along the lines of ply wood of some sort, something stronger with atleast the same density.

Is that feasible?

~Levi

i don't know alot about wood. how about oak? it'd weigh 600 pounds then.

Worlddre
11-16-2006, 09:40 PM
I know I can use that, but I do not like the stuff. Working with it in the past, it likes to crumble out when being worked with. I was thinking more along the lines of ply wood of some sort, something stronger with atleast the same density.

Is that feasible?

~Levi

where did you get it as no mdf ive ever worked with has ever crumbled while i was doing anything to it... if you dont mind spending $60+ a sheet baltic birch ply is the sexiness

seth350
11-16-2006, 09:43 PM
http://images.rockler.com/rockler/images/63388-01-500.jpg
baltic birch ply ^

Frankensuby
11-16-2006, 09:45 PM
where did you get it as no mdf ive ever worked with has ever crumbled while i was doing anything to it... if you dont mind spending $60+ a sheet baltic birch ply is the sexiness


Well, trying to jigsaw the stuff, it just crumbles apart at the edges, and I'm a freak about clean edges. Plus, drilling through it, when the bit or screw comes out the other side, it bulges then breaks chunks away...and it is HD stuff.

I vaguely remembering seeing a thick 5 ply sheet of plywood for roughly 25$ Atleast i think it was 5 ply, either way, the stuff was insanely ridgid. I guess I need to figure out density though.

I'm gonna try to find an enclosure designer or something and draw up a picture. Basically, I'm going to build an enclosure that covers the entire back of the rear seat in the trunk, making it look like a wall. This is where I will mount my amps and wiring to as well.

Chevyaudio
11-16-2006, 09:46 PM
Birch ply works well too. Also pick up some 90 degree angle corner clamps...they help a ton.

Frankensuby
11-16-2006, 09:47 PM
Birch ply works well too. Also pick up some 90 degree angle corner clamps...they help a ton.


As in something akin to C-Clamps? or benchclamps? Or is that some sort of nailing item?

I can get Oak sheets as thick as I want, but they are not pressure treated. My father is a lumberjack with a mobile bandsaw :D. I'll see if he has anything outback, but like I said, he doesn't have anything pressure treated so it might warp over time.

~Levi

bri487
11-16-2006, 09:49 PM
3/4 mdf. It is the best balance of weight, price, structural integrity, and acoustics. There is really no need for anything else in a car.

You can use 5/8 in a pinch.

unless you are running a stupid pair of 15"s or something, then 1" for the front baffle.

and dont use super 90 adhesive. get a better quality glue and a gun

Frankensuby
11-16-2006, 09:51 PM
unless you are running a stupid pair of 15"s or something, then 1" for the front baffle.

and dont use super 90 adhesive. get a better quality glue and a gun

My issue with that is that usually the good glues only come in 5 gallon buckets. Rick over at Raamaudio sells a great adhesive, but I've used the #90 for carpeting and it worked perfectly.

~Levi

bri487
11-16-2006, 09:55 PM
My issue with that is that usually the good glues only come in 5 gallon buckets. Rick over at Raamaudio sells a great adhesive, but I've used the #90 for carpeting and it worked perfectly.

~Levi

it isnt half as good as other stuff. i have never had carpet peel up at all before, not even at seems on corners.

NightHawkFG
11-16-2006, 10:45 PM
I have never had MDF cumble on me. are you sure you are not confusing MDF with particle board.

ssj2xxgotenxx
11-16-2006, 11:23 PM
http://i50.photobucket.com/albums/f340/ssj2xxgotenxx/P1000063.jpg

Immacomputer
11-16-2006, 11:35 PM
Well, trying to jigsaw the stuff, it just crumbles apart at the edges, and I'm a freak about clean edges. Plus, drilling through it, when the bit or screw comes out the other side, it bulges then breaks chunks away...and it is HD stuff.

I think you're talking about particle board and not MDF. MDF does not crumble at all.

Thieroff
11-16-2006, 11:40 PM
MDF splits easily though, be sure to drill out some pilot holes


CT

bjfish11
11-17-2006, 12:31 AM
As said, particle board will crumble. Particle board does not = MDF.
Other available wood is Trupan (Light MDF) and Baltic Birch ply. Both are more expensive than MDF, but superior materials

For glue, I use 3M Super 77, great glue. I have a hard time peeling it off, even if I want to. Never used the 90 stuff.

Then just a good wood glue, and sheet rock screws, and your tools. Then your set.

GrnEydDvl
11-17-2006, 12:37 AM
Other available wood is Trupan (Light MDF) and Baltic Birch ply. Both are more expensive than MDF, but superior materials


Why is Light MDF superior? Just because of the weight? I saw it at the wood store the other day but passed it by thinking it would be less sound than MDF.

bjfish11
11-17-2006, 12:39 AM
Yes, basically weight. Personally, I think it cuts easier and routes easier. I have also never had a screw strip out in Trupan.

Frankensuby
11-17-2006, 01:13 AM
My apologies guys, it is splitting. Not crumbling. I could not think of the right term so I wrote crumble. Trust me, I know what Particle board is; it's the stuff Walmart makes their enclosures out of.

The pic of the items needed.....I think I mentioned every one of them :D

I'm hitting up the Depot tomorrow after work, I need to sketch this thing out too.

~Levi

Big Dee
11-17-2006, 01:51 AM
If your MDF is splitting you aren't doing it right. I've never had MDF split on me at all.

If you want to use something else get some Birch Ply.

Immacomputer
11-17-2006, 08:50 AM
If it's splitting, don't use so many screws (or don't use them at all) and make sure to pre-drill them. Also, make sure that the screws are at least 5-6" away from the edge of the wood. That will help reduce splitting.

Rawr-DQ
11-17-2006, 10:38 AM
If it's splitting, don't use so many screws (or don't use them at all) and make sure to pre-drill them. Also, make sure that the screws are at least 5-6" away from the edge of the wood. That will help reduce splitting.

...laugh, just pre-drill the holes, make sure you don't drill a hole too large so that the screws strip out the wood, or too small, to where the wood splits.

Immacomputer
11-17-2006, 11:39 AM
...laugh, just pre-drill the holes, make sure you don't drill a hole too large so that the screws strip out the wood, or too small, to where the wood splits.

You can laugh all you want but from the testing I have done, MDF will split even with predrilled holes, especially if he is using 1.5" screws. I used 1.25" course threaded drywall screws and a scrap piece of MDF; I wanted to see if it would split with predrilled holes. Sure enough, the wood slightly split when they were placed about 4" away from the edge. I tried going up one size for my drill bit and the screws wouldn't really hold. When I tried them about 5" away, the splitting was very minimal. Was the splitting terrible? No, and with woodglue there, it's really not a problem. Would I recommend putting a ton of screws in 3-4" apart? Hell no.

bjfish11
11-17-2006, 03:16 PM
Just properly predrill your holes and you will be fine. I dont have any splits and mine are usually 2-3 inches from the edges of the wood. I use 1 5/8" Drywall screws.

Frankensuby
11-18-2006, 12:30 AM
Ok I went with MDF 3/4" because the sheets of plywood and other various woods looked like they would splinter too easily.

My next issue is that I cannot for the life of me find a plain answer for how much volume my driver displaces in an enclosure. I need .65 volume in a sealed box including the driver's displacement. On the spec sheets, it has all sorts of infor, Vas, Xmax, Qts, etc.... but I don't know which is the displacement figure :(

Any advice?

Mugen
11-18-2006, 12:35 AM
Ok I went with MDF 3/4" because the sheets of plywood and other various woods looked like they would splinter too easily.

My next issue is that I cannot for the life of me find a plain answer for how much volume my driver displaces in an enclosure. I need .65 volume in a sealed box including the driver's displacement. On the spec sheets, it has all sorts of infor, Vas, Xmax, Qts, etc.... but I don't know which is the displacement figure :(

Any advice?

What sub are you using? And if I were you, I'd just shoot for .75ft^3, that'll give you plenty of leeway on your displacement and you likely won't be able to tell any bit of difference in the way it sounds. What sub are you using though?

Immacomputer
11-18-2006, 12:49 AM
Any advice?

Don't worry about it and shoot for a little bit bigger. You won't be able to tell the difference either way.

thatkidbob
11-18-2006, 12:55 AM
i can't remember the exact size off hand, but i use a 1/4" or 3/16" bit for my predrilling, a 5/8 for countersinking, and 1 1/2" long #7 deck screws... i get splits once every blue moon...

As far as materials, heres what i use:
-A circular saw (used w/ a saw guide for cutting my pieces)
-A router (used w/ circle jig for cut outs, flush bit for finishing work, and rounder bit for roundovers)
-A drill (duh :) )
-2 90 degree corner clamps (the cheapies from harbour freight)
-2 36" bar clamps (again, harbour freight)
-2 48" bar clamps (uhh... harbour freight)
-hurricane nuts (for speaker mounting)
-bondo (for filling the countersunk holes)
-primer & paint (for the port)
-weldwood contact cement (slower than spray adhesive, but bonds stronger)
-fiberglass resin (for sealing the box)

Frankensuby
11-18-2006, 11:47 AM
The Driver is a Xenon 10" 2 ohm. It has a chart, with .42 internal volume(with driver) going for SPL, and .85(with driver) as an SQ oriented build. I was thinking .65 to .75 with driver would be good for me.

As far as resin, I've never used the stuff, but my dad has 2 gallons of it after his repairs on his log truck (fiberglass hoods on the big trucks). Is it just apply and let set situation? This would help me make the box fit perfect to the trunk wall ;)

~Levi

Immacomputer
11-18-2006, 12:57 PM
When they say the SPL enclosure being small, that means it's going to have a peak in the upper frequency spectrum and it will have very little low end. If you don't care about having low end, .65 will probably be fine.

Frankensuby
11-18-2006, 01:33 PM
I thought SQ was when there was very little low bass, but more accurate reproduction? I'm aiming at 75% SQ with some 25% extra bass. Hence the .65 volume with driver.

So to achieve that, you are saying I'd be better off with a .55 for my idea? I'm new to sub box designs, I apologize.

~Levi

Big Dee
11-18-2006, 02:23 PM
I thought SQ was when there was very little low bass,
~Levi

:eyebrow:

lilmaniac2
11-18-2006, 02:24 PM
I thought SQ was when there was very little low bass, but more accurate reproduction? I'm aiming at 75% SQ with some 25% extra bass. Hence the .65 volume with driver.

So to achieve that, you are saying I'd be better off with a .55 for my idea? I'm new to sub box designs, I apologize.

~Levi

i wanna know how u take percentages of things that arent numbers?

Immacomputer
11-18-2006, 02:51 PM
So to achieve that, you are saying I'd be better off with a .55 for my idea? I'm new to sub box designs, I apologize.

~Levi

No. The smaller you go, the more of a peak you will create, thus the louder the box will be at higher bass frequencies. The smaller the enclosure, the less low end response you will have.

Give me the T/S parameters and I'll get you a proper size for that sub.

Frankensuby
11-18-2006, 02:58 PM
i wanna know how u take percentages of things that arent numbers?

As stated before,
.85 cubic feet with drivers' volume= Musical (reprodcution)
.42 cubic feet with drivers' volume= SPL

So actual 75%/25% split is either
.6375/.2125 for Musical split (desired) = .6375 for musical 75%/25%
.3150/.1050 for SPL = .5250 for SPL 75%/25%

If my math is correct :crap:

As for the :eyebrow: I meant as in better high response punch rahter than lower bass (rock listening rather than rap) in a sealed enclosure.

On a side note, the enclosure rough sketch i made only has .64 volume without the driver :crap:

~Levi

Immacomputer
11-18-2006, 03:01 PM
As stated before,
.85 cubic feet with drivers' volume= Musical (reprodcution)
.42 cubic feet with drivers' volume= SPL

So actual 75%/25% split is either
.6375/.2125 for Musical split (desired) = .6375 for musical 75%/25%
.3150/.1050 for SPL = .5250 for SPL 75%/25%

If my math is correct :crap:

As for the :eyebrow: I meant as in better high response punch rahter than lower bass (rock listening rather than rap) in a sealed enclosure.

On a side note, the enclosure rough sketch i made only has .64 volume without the driver :crap:

~Levi

Low bass is NOT just for rap, that is a terrible generalization.

Link me to the sub. Is this the correct sub:
ftp://208.187.38.55/Phoenix_Gold/Manuals/Speakers/xenon/

If it is, I would do no less than 1 cubic foot. They recommend 1.65 for musical and I agree with it all the way.

Frankensuby
11-18-2006, 03:07 PM
No. The smaller you go, the more of a peak you will create, thus the louder the box will be at higher bass frequencies. The smaller the enclosure, the less low end response you will have.

Give me the T/S parameters and I'll get you a proper size for that sub.

Phoenix Gold Xenon 10" 2-ohm:
T/s Parameters:
Fs=18.7Hz
Re=3.46 ohm (series)
QMS= 30.19
QES=.43
Qts=.42
Vas= 43.97 Liters
Mms=277.7 grams
Cms=260 uM/newtons
BL=16.3 Testa-M
SPL(2.83 volts)=85.31 dB
Sd=346.4 sq. cm
Xmax=40MM p-p *measured*

Hope that helps :)

~Levi

Frankensuby
11-18-2006, 03:10 PM
Low bass is NOT just for rap, that is a terrible generalization.

Link me to the sub. Is this the correct sub:
ftp://208.187.38.55/Phoenix_Gold/Manuals/Speakers/xenon/

If it is, I would do no less than 1 cubic foot. They recommend 1.65 for musical and I agree with it all the way.

Sorry for the generalization, once again new to this thing. I've only dealt with midbass up.

Are you looking at vented? It does say 1.7 for vented, but I am working with a sealed box.

Technical sub name is X10d2

~Levi

CJL
11-18-2006, 03:24 PM
As said, particle board will crumble. Particle board does not = MDF.
Other available wood is Trupan (Light MDF) and Baltic Birch ply. Both are more expensive than MDF, but superior materials

hmm I never heard of this before,how much more is it compared to MDF?

Immacomputer
11-18-2006, 03:47 PM
Sorry for the generalization, once again new to this thing. I've only dealt with midbass up.

Are you looking at vented? It does say 1.7 for vented, but I am working with a sealed box.

Technical sub name is X10d2

~Levi

The manual I downloaded was for a different generation of the Xenon line. The parameters were very different.

For your sub, I would do between .7-.85 cubic feet. That would give you a smooth and flat response and still be able to get pretty low while sounding nice. Your .65 would work as well.

azbass
11-18-2006, 03:50 PM
wood: check
glue: check

stuff to put box together: check

Frankensuby
11-18-2006, 04:16 PM
The manual I downloaded was for a different generation of the Xenon line. The parameters were very different.

For your sub, I would do between .7-.85 cubic feet. That would give you a smooth and flat response and still be able to get pretty low while sounding nice. Your .65 would work as well.

What is the Drivers' volume so I can add that into my box design? I really wish I could figure it out.

My current box design is about .64 Without the driver. So obviously I need to add something to that, or polyfill.

~Levi

bjfish11
11-18-2006, 04:34 PM
hmm I never heard of this before,how much more is it compared to MDF?

I havent bought MDF in years, so I dont know the price of that ($15-20?), but I pay around $28 per sheet for Trupan.

Frankensuby
11-19-2006, 05:56 PM
Ok, well I bought all the stuff needed, and made the preliminary cuts. People helping me out with the internal volume figures have been as low as .64 internal and as high as 1.1 internal volume, so I'm gonna guess it will be about .75-.8 internal volume without the driver.

I know I need to recut one piece because I was in a rush to get the cuts done before work, but so far it looks promising, albeit a little small.

Is it true that polyfill will make the sub think it has more volume?

If so, I might grab a bag of that in case my internal volume is a bit smaller than I wished.

I'll try to get pics up in a day or two, depending on progress.

~Levi

Frankensuby
11-19-2006, 07:33 PM
Another rather random question: Is the 3/4" MDF at Home Depot vinyl laminated? The Sealant I got says not to use it one vinyl laminated MDF.

Thanks,

~Levi

CJL
11-20-2006, 12:05 AM
I havent bought MDF in years, so I dont know the price of that ($15-20?), but I pay around $28 per sheet for Trupan.

How would Trupan compare to Birch?

bjfish11
11-20-2006, 12:06 AM
Birch is about .1 pounds per square foot lighter, but runs around $.25 more per square foot.

Frankensuby
11-23-2006, 12:10 PM
Alright guys, always use a table saw for straight cuts :mad:

I have the box mostly together, and the first round of adhesive is drying now. As I posted earlier, I had to use a jigsaw for lack of better equipment. Next time I do this, I'm definitely going to use a table saw of some sort. My edges were bad, although I planed most to sit flush, there was 2 spots that I could do nothing about because if I planed them flat, it would throw the rest of the edges off.

I ended up using alot of construction adhesive to fill in these spots. I threw a bead in the middle, threw it together, and then threw and layed a wide bead on the inside and outside of the problem areas. I've worked with this glue before, and it is meant to keep medium sized boulders and rocks in place in Landscaping, but is excellent for high pressure wood situations. I hve applied this glue to each pilot hole I put in, and to each surface screwed together. My concern is that one area probably has a span of 2/16" that I had to fill in. Do you think I should be ok after its' finally cured in 7 days?

I've ripped MDF apart with this glue holding together, but that was on flush edges. I'm also going to be using aquarium silicone to add to the internal seal before I finish fiberglassing. Will this balance out my mistakes?

By the way, I think the box looks ok for a first time builder :D Pics by the end of the night ;)

~Levi