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View Full Version : Mdf vs. Ply?



DakotaSPL
10-10-2012, 06:50 PM
i have plenty of ply laying around but mdf is over 30 bucks a sheet and ill need 9 sheets of that to make a box, 3 layer front 2 on each side with bracing inside all glued and screwed bout a 10 cube or so box same as one in my pictures, so that being said wont both be just as equally strong when its all said and done? honestly in the past i had noticed no difference from a mdf or ply box construction of same dimensions or I could be going deaf... thoughts?

CHEMMINS
10-10-2012, 06:53 PM
Use what ya got.......most people can't notice a difference.

Jes 42
10-10-2012, 06:57 PM
^ that

Kangaroux
10-10-2012, 06:59 PM
Make sure the ply doesn't have any obvious voids in it. Not only can it cause extra resonances but it also lowers its strength by a lot.

DakotaSPL
10-10-2012, 07:08 PM
thanks for the input, i figure after i cover the box who would be the wiser

cyn
10-10-2012, 07:33 PM
Ply/MDF etc... all sounds close to the same.. Ply is just tons lighter in weight than MDF... I prefer Birch or Japanese Maple myself because of the Weight.. and it does tend to have a slightly different sound to it.. But to the avg. person they would not notice it one bit.. Like the ones before me said, use what you have, and make sure when you cut it to check the layers to make sure there is no Voids.. Alot of the china pressed plys have tons of voids in them.

DakotaSPL
10-15-2012, 03:14 PM
well got it all put together for the most part, went 4 layers on front and 3 layers on each side still got a lot to do on it, this thing is solid as a rock without a dowel in center, still going to use one tho, still got 45's to make as well, hate doing those without a table saw

DakotaSPL
10-15-2012, 03:16 PM
and gained 3 more cubes by doing more measuring https://sphotos-b.xx.fbcdn.net/hphotos-ash3/543239_473836195988546_1801064845_n.jpg

wickedwitt
10-15-2012, 03:26 PM
9 sheets to make a 10 cu box? No way. We just made a 15.5 cu box w/ 5 sheets. Double face front, single everywhere else with proper bracing. Thing weighed 450lbs before subs.

DakotaSPL
10-15-2012, 03:29 PM
still took me 9 sheets to make this, avoiding bad corners and voids, plenty of scraps to make my filler on each side of wall for some mids, and screwed up one side, wasted a tube of glue lol

Kangaroux
10-15-2012, 03:32 PM
For the record that's not really the ply we were talking about, what you used is OSB. You would want something like this:

http://images.rockler.com/rockler/images/63388-01-200.jpg
http://www.woodbusinessportal.com/poze_mesaje/200859.1.jpg

Jes 42
10-15-2012, 03:33 PM
that turned out nice man

DakotaSPL
10-15-2012, 03:36 PM
ah, sorry so use to calling that stuff ply, but i did use that on the face, still really strong stuff, i sanded and glued then screwed each layer together and left it to cure 24 hrs, have less then 100 invested so im **** happy with it lol, glue and screws is whats costly, used leftover osb and sand paper, more sanding to do and using undercoating to paint it.

DakotaSPL
10-15-2012, 03:37 PM
For the record that's not really the ply we were talking about, what you used is OSB. You would want something like this:

http://images.rockler.com/rockler/images/63388-01-200.jpg
http://www.woodbusinessportal.com/poze_mesaje/200859.1.jpg

they wanted over 90 bucks per sheet for these bad boys at my local lumber place

PIMPSLAPN
10-15-2012, 03:39 PM
i was think about usein them textured spay paints

Kangaroux
10-15-2012, 03:39 PM
they wanted over 90 bucks per sheet for these bad boys at my local lumber place

Was it 13 ply baltic birch? You can pick up some ply wood that isn't absolutely amazing but still doable for around $35 at your local HD/lowes. Birch is usually $45 a sheet at hd/lowes.

DakotaSPL
10-15-2012, 03:45 PM
it was 7 ply i think but with 3 layers of the 1/2 osb glued and screwed to it, stronger then i thought it would be, glad it isnt mdf im so scared of breaking that stuff. and not having to pre drill all the holes is a plus, just screw it and move on, nothing split

DakotaSPL
10-15-2012, 03:46 PM
Was it 13 ply baltic birch? You can pick up some ply wood that isn't absolutely amazing but still doable for around $35 at your local HD/lowes. Birch is usually $45 a sheet at hd/lowes.

my local place isnt the greatest, one of those 9 out of 10 2x4's twisted and bowed kinda places

double 07
10-15-2012, 04:04 PM
If you do another PLY enclosure look for Arauco 23/32"....I have built a ton of enclosures out of it including my personal one without a problem.....just brace it properly like you would any other enclosure....

Fi-brations
10-15-2012, 04:12 PM
Was it 13 ply baltic birch? You can pick up some ply wood that isn't absolutely amazing but still doable for around $35 at your local HD/lowes. Birch is usually $45 a sheet at hd/lowes.

you can only get that 13ply baltic stuff from Russia

Kangaroux
10-15-2012, 04:21 PM
you can only get that 13ply baltic stuff from Russia

My local HD sells it but it's only in 2x2 project panels

maylar
10-15-2012, 05:08 PM
Was it 13 ply baltic birch? You can pick up some ply wood that isn't absolutely amazing but still doable for around $35 at your local HD/lowes. Birch is usually $45 a sheet at hd/lowes.

Just picked up a half sheet (24x48") from Home Depot for $19. 13 ply Birch (not Baltic). They also had 3/4 "hardwood" ply for a few bucks more. White wood, looked like poplar.

Kangaroux
10-15-2012, 05:09 PM
Just picked up a half sheet (24x48") from Home Depot for $19. 13 ply Birch (not Baltic). They also had 3/4 "hardwood" ply for a few bucks more. White wood, looked like poplar.

Yep it's poplar. They have poplar at my HD that's on clearance and I use that for my builds. Did it have the veneer on it?

CHEMMINS
10-15-2012, 05:12 PM
you can only get that 13ply baltic stuff from Russia


Say wut? You can get Russian Baltic Birch anywhere. Any decent wood place sells it (aka not a box store). Usually in a 5x5' sheet. 4x8' can be had but very rare.

Fi-brations
10-15-2012, 06:38 PM
Say wut? You can get Russian Baltic Birch anywhere. Any decent wood place sells it (aka not a box store). Usually in a 5x5' sheet. 4x8' can be had but very rare.
I read a thread on diyma that had a lot of ppl discussing it, something about the true 13 ply baltic was only available buying directly from Russia, but I would not be surprised if an actual wood store had it

CHEMMINS
10-15-2012, 06:48 PM
I read a thread on diyma that had a lot of ppl discussing it, something about the true 13 ply baltic was only available buying directly from Russia, but I would not be surprised if an actual wood store had it

I should find that thread over there......cause them 2 sheets I have in my garage would probably make them crap a brick......especially since I got it local.

Imtjnotu
10-15-2012, 07:07 PM
some ply is easy to bend....depends on the quality but most home depot is good....generally ive seen people who use ply resin the inside

Fi-brations
10-15-2012, 07:08 PM
I should find that thread over there......cause them 2 sheets I have in my garage would probably make them crap a brick......especially since I got it local.
Can't find it :/ but found this thought it was interesting
Birch vs. MDF test (spl results inside) - Realm of Excursion (http://forum.realmofexcursion.com/enclosures/39674-birch-vs-mdf-test-spl-results-inside.html)
Birch vs. MDF test (spl results inside)



two identical box's were made. one out of mdf, and the other birch. the specs on them are 1.25 cubic feet net with .75'' wood thickness. each had a 12'' type R. both box's were sanded in the interior walls with the same grit sand paper. both speakers were brand new. voltage was held constant on battery.

mdf:
1100 watts: 139.8
2800 watts: 143.7

birch
1100 watts: 139.8
2800 watts: 143.7

both had the same output. this may change when larger box's are used, but when small box's are used one does not have the benefit over the other in terms of spl.
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Ignatowski
10-15-2012, 07:20 PM
i have plenty of ply laying around but mdf is over 30 bucks a sheet and ill need 9 sheets of that to make a box, 3 layer front 2 on each side with bracing inside all glued and screwed bout a 10 cube or so box same as one in my pictures, so that being said wont both be just as equally strong when its all said and done? honestly in the past i had noticed no difference from a mdf or ply box construction of same dimensions or I could be going deaf... thoughts?

crazy....plywood for a sub box......

srb
10-15-2012, 07:40 PM
If you do another PLY enclosure look for Arauco 23/32"....I have built a ton of enclosures out of it including my personal one without a problem.....just brace it properly like you would any other enclosure....

That stuff is nice. And fairly cheap. But I work at HD and it's seasonal product and we sell out of it QUICK.

Imtjnotu
10-15-2012, 07:56 PM
wait he isnt talking birch ply?

mat3833
10-15-2012, 11:53 PM
im about to build 2 boxes out of "Cabinet quality ply" not entirely sure if thats the REAL name but i got a ton of it for free the other week helping my buddy move. he got it to make cabinet doors, bookshelves, and he even made a home theater stand thingy out of it. its 3/4 and the crap is heavy as hell(a 2X4 sheet weighs more than a 4X8 sheet of 3/4 ply. it doesnt even seem to have layers. id love to figure out what it is since it looks nice and seems like it would be really nice for enclosures.

Matt

gckless
10-15-2012, 11:56 PM
im about to build 2 boxes out of "Cabinet quality ply" not entirely sure if thats the REAL name but i got a ton of it for free the other week helping my buddy move. he got it to make cabinet doors, bookshelves, and he even made a home theater stand thingy out of it. its 3/4 and the crap is heavy as hell(a 2X4 sheet weighs more than a 4X8 sheet of 3/4 ply. it doesnt even seem to have layers. id love to figure out what it is since it looks nice and seems like it would be really nice for enclosures.

Matt

Quality of ply is usually associated to number of layers. Not always of course, but generally speaking the more layers the higher quality it usually is. My box is currently made out of 11 ply birch. You said it don't have layers? Is it particle board? If it's heavier than twice the amount of MDF, chances are pretty good it's not plywood.

Jerhemy
10-16-2012, 12:07 AM
im about to build 2 boxes out of "Cabinet quality ply" not entirely sure if thats the REAL name but i got a ton of it for free the other week helping my buddy move. he got it to make cabinet doors, bookshelves, and he even made a home theater stand thingy out of it. its 3/4 and the crap is heavy as hell(a 2X4 sheet weighs more than a 4X8 sheet of 3/4 ply. it doesnt even seem to have layers. id love to figure out what it is since it looks nice and seems like it would be really nice for enclosures.

Matt

Probably some form of high density fiber board, much like MDF. Should work out very nice for a box! Great free score, too.

Dtrom
10-16-2012, 12:18 AM
My box is made from araucoply. It's stronger, and better looking bare then any mdf box I've owned.

mat3833
10-16-2012, 12:23 AM
its wood of some kind. you can see the grain in it. i helped him move the bookshelf he built with it and FML it was heavy. he had stained it and it looked like cherry or something. ill see if i can get a good picture of it tomorrow sometime. i may be crazy about the layers since it HAS been cut but idk.

Matt

oh and it ISNT OSB or particle. but it is heavy. probobly going to end up with 60 lb 2.7 cube boxes....

mat3833
10-17-2012, 02:22 PM
hmm, well i took a closer look at it today and pulled the smaller peices out of the shed and it does infact have layers. it seems to be 4 layers. the 2 outer layers look and "feel" like a really white wood and the 2 inner layers look like a thin layer of MDF and something else. i couldnt get a decent pic of the layers so no go there.

Matt

mat3833
10-17-2012, 11:20 PM
heres some crappy *** pics of three diferent edges of it. upon VERY close inspection there are 7 layers. the two outer-most layers apear to be really thin wood, about a MM thin but real wood. then you have a layer of something, a layer of what appears to be MDF, a layer of something else, a layer of something that looks like wood, another layer of what apears to be MDF, and then another layer of something.

honestly i have no clue WTF this crap is. but you can hit it with a hammer fairly hard and it doesnt dent, and when you tap it it sounds "dead" any ideas?

Matt

gckless
10-17-2012, 11:45 PM
Veneered concrete FTW.

hispls
10-17-2012, 11:56 PM
That adventech flooring is really solid as well. A guy up here that does 160's in a couple vehicles swears by it.

mat3833
10-18-2012, 12:05 AM
are you saying that thats what it is? lol, because i must respectully say you are a horrible troll or a moron.

Matt

mat3833
10-18-2012, 12:24 AM
ok, so after some research it apears i have "7 ply oak vaneer MDF core ply".... its 7 layers plus a thin vaneer of oak on each side. the "core" is oak strips, then the next layers are MDF, then more pine, another layer of MDF. so you end up with this:

Vaneer - MDF - Pine - MDF - Oak - MDF - Pine - MDF - Vaneer

never heard of this crap, but my buddy got it from a lumber yard about an hour away. i contacted them and that ^ is what they told me i had. aparently its dense, resists moisture(within reason), and has good "anti-split) and de-lamination properties. the guy i talked to seemed to kno wtf he was talking about but IDK. think its worth building boxes out of? the wood looks nice and since its going in my livingroom thats a BIG plus.

Matt

Kangaroux
10-18-2012, 12:26 AM
ok, so after some research it apears i have "7 ply oak vaneer MDF core ply".... its 7 layers plus a thin vaneer of oak on each side. the "core" is oak strips, then the next layers are MDF, then more pine, another layer of MDF. so you end up with this:

Vaneer - MDF - Pine - MDF - Oak - MDF - Pine - MDF - Vaneer

never heard of this crap, but my buddy got it from a lumber yard about an hour away. i contacted them and that ^ is what they told me i had. aparently its dense, resists moisture(within reason), and has good "anti-split) and de-lamination properties. the guy i talked to seemed to kno wtf he was talking about but IDK. think its worth building boxes out of? the wood looks nice and since its going in my livingroom thats a BIG plus.

Matt

If it has any sort of MDF to it it's not moisture resistant whatsoever...especially if the only thing protecting the MDF layer is a thin veneer. Never heard of ply that used MDF as one of the plys though, that's interesting...how much was it?

RAM_Designs
10-18-2012, 12:30 AM
Maybe I'm paranoid, but I can hear the difference in MDF vs Arauco...and in small boxes too. I prefer the sound of MDF, but I'm sure if I doubled up everywhere I probably couldn't tell the difference since they'd both be pretty dead at that point with a 2ft^3 gross box.

mat3833
10-18-2012, 12:41 AM
aparently it goes for ~90 a sheet depending on the grade of the vaneer. and he said moisture resistant because the vaneer is waterproof and the layers are glued and then heat pressed together. im not sure how much of this is BS or whatnot, but this stuff looks pretty darn nice. aparenttly its so heavy because the MDF gets squished by almost 20% during the pressing process. he said a 4X4 sheet of 3/4 weighs ~47 lbs.

Matt