# Birch or MDF for Subwoofer Enclosure



## captainscarlett

I've been adviced to use birch for subwoofer enclosures. I just need to hear arguements for/against using either birch or MDF. 

Does Birch splinter easily? Is it harder to work with?


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## Gary S

In theory the MDF might be more dense and offer better performance. But I don't know if it would make a noticeable difference in the real world. The Birch might last longer and resist humidity better. I don't have a problem working with either.


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## ALloyd919

The biggest issue is moisture. Birch will stand up to humid climates MUCH better than MDF. As far as rigidity and the like, as long as you brace properly it will be negligible.

Birch=Humid Climates/Marine
MDF=Everything else


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## ALloyd919

Oh, and as long as your saw is sharp and you take your time you don't have to worry about splinters with birch.


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## ATOMICTECH62

The good thing about Birch is that it can be stained and clear coated for that pro look.
Nice for house speakers also.


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## Jonny Hotnuts

Medite and Medex are superior to standard MDF for building sub boxes in every respect. 

~JH


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## oldno7brand

I just built mine with Birch from what I understand it is a bit lighter but the only thing I hate is the splintering. No matter what we were doing it peeled and splintered.

(Bit unnerving) 

If I had to do it over again likely just 3/4 mdf (SQ build) but its working


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## jp88

birch is lighter, stiffer, and holds up to abuse and moisture better. It also holds screws better.
Mdf is denser and cheaper.


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## captainscarlett

ALloyd919 said:


> Oh, and as long as your saw is sharp and you take your time you don't have to worry about splinters with birch.





oldno7brand said:


> I just built mine with Birch from what I understand it is a bit lighter but the only thing I hate is the splintering. No matter what we were doing it peeled and splintered.
> 
> (Bit unnerving)
> 
> If I had to do it over again likely just 3/4 mdf (SQ build) but its working


I guess for me its going to be trial and error. Thanks for your replies so far. I'll try and look for good quality stuff ... which at the moment Marine bich seems to get a lot of mention.


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## stochastic

Are you talking about solid birch or birch ply?


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## captainscarlett

stochastic said:


> Are you talking about solid birch or birch ply?



I've been told to go for 'Birch Ply'


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## Candisa

I always used MDF for building installs and other audio-related projects, but now in Xenia's car, I'm using 18mm Meranti-ply, I think it's 9 ply's.

MDF is easier to saw and sand into shape without splintering, since it's basically grinded wood mixed with glue, there are no long fibres in it...

With the meranti-ply, every saw-cut is splintered at 1 side, even when using a very fine saw-blade and taking time, so if you want nice sharp 90° cuts, MDF is the way to go.
I chose meranti-ply-wood because of it's strength. 
If you take a piece of 8mm MDF, you'll have to use a bit of force, but then it'll break quite easily. Do the same thing with the same thickness of meranti-play, it'll bend a little faster and the top layer will start to crackle, but it'll take longer and more energy to break it completely because of the long fibers that have a different direction in every layer...

The best stuff is the plywood they use to make molds for concrete walls/beams/... That's ordinary plywood with an epoxy-coating on it on both sides. Because of that coating, it's a lot stronger than regular plywood and it doesn't splinter when cutting it!
It is more expensive though...


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## captainscarlett

Candisa said:


> I always used MDF for building installs and other audio-related projects, but now in Xenia's car, I'm using 18mm Meranti-ply, I think it's 9 ply's.
> 
> MDF is easier to saw and sand into shape without splintering, since it's basically grinded wood mixed with glue, there are no long fibres in it...
> 
> With the meranti-ply, every saw-cut is splintered at 1 side, even when using a very fine saw-blade and taking time, so if you want nice sharp 90° cuts, MDF is the way to go.
> I chose meranti-ply-wood because of it's strength.
> If you take a piece of 8mm MDF, you'll have to use a bit of force, but then it'll break quite easily. Do the same thing with the same thickness of meranti-play, it'll bend a little faster and the top layer will start to crackle, but it'll take longer and more energy to break it completely because of the long fibers that have a different direction in every layer...
> 
> The best stuff is the plywood they use to make molds for concrete walls/beams/... That's ordinary plywood with an epoxy-coating on it on both sides. Because of that coating, it's a lot stronger than regular plywood and it doesn't splinter when cutting it!
> It is more expensive though...


As a beginner, I wonder if going to a timber merchant and getting them to cut it for me would be the best bet?

The comment given to me was to the effect of: use brich ply because it will show people tht you care about your products and that as a box builder (which i really want to get into) it also show you won't compromise your products and that you're not in it for the money etc, etc, (you get the picture).


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## Candisa

If you have a timber merchant that is precise with measurements and cuts, I'd always recommend to let them do most of the cutting. These guys have professional machinery and lots of experience, but sometimes, you have to do something yourself.
For example, where I buy my sheets of wood, they have a great machine and experienced worker to cut rectangular shapes, but they can't do trapediums, triangles, circles... and they can't do a 45° cut, simply because their machine isn't made for this.
Sometimes, wood-shops have a CNC-router available and then they can do anything you want, including angled cuts, perfect round holes...

That comment is (crap of a male cow), a box made of MDF can sound just as good as a box made out of plywood, and it's easier to cut with hobby-equipment. 
The only downside of MDF is the strength of it: you have to use at least 1" thick MDF to get the same solidness and toughness as with 3/4" ply, depending on the quality of the plywood and the MDF.

For subwoofer cabinets I always use 30mm (1 1/4") thick MDF, but now in the Saab I decided to use 3/4" meranti-ply to get the same strength out of thinner and lighter material (but it's harder to cut properly) because a Saab 900 classic is known for it's rather weak rear-suspension and I don't want to mess up it's great weight-balance too much.


For a planned home-audio project, I'm planning to use 30mm MDF for the bass-cabinet and 12-15mm plywood for the upper mid+tweeter cabinet to keep the gravity point low, which will increase the stability of the total speaker compared with all-MDF or all-ply.


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## rexxxlo

I have issues with mdf here are my pros and cons.


Mdf cons : its dust is carcinogenic
is like a sponge if it gets wet its ruined
its hard on tools (saws routers)
It has no screw holding strength whatsoever and if you want to use a screw you need to predrill or it swells out making leaky joints or baffles
It doesn't paint consistantly on end grains and faces
It chips off corners when mistakes are made
Brads shoot wildly through it coming out the sides at very slight angles making finishing difficult
It truly has no strength unless its built into a box of some sort

Pros: it routers nice 
Some people believe its more dense making a better non resonant enclosure
its usually cheaper than plywood variants

Ply/ birch Cons:
It splinters when cut sometimes
Its more expensive usually

Pros:
Its stronger
The dust is not nearly as unhealthy and doesn't stay floating for weeks in your shop
Tools last longer 
It takes screws ( repeatedly without loosing strength or grip)
It takes brads and they go where they are told
Glues great
Paints the same on end grains usually
If you desire to build with screws they can be sunk under the surface and filled over with bonding making it invisible without predrillig

I'm sure there is more 




Sent from my GT-P7510 using Tapatalk


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## DESTROYERRACER

you in buffalo new york rexxxlo?and those are all very interesting points.....in the process of making materials decisions for my box build as well id like to see some more comments.i think after reading this i very well may go to birch instead of the planned mdf.im exposed to enough carcinogens and i like strength altho for a single SWR-843D mdf would prob be plenty strong.it is going in a truck tho and may very well see some shockloads and whatnot.....


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## ogg

You can cut _most_ plywood without splintering by scoring it with a utility knife just shy of the cut line. If it's poor quality or it's gotten wet it may splinter and peel no matter what.
IMO, If you're planning to paint it you should avoid exposing any end grain and miter your corners with either plywood or MDF. At the very least put a thin layer of filler on the end grain before you sand it.


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## adrenalinejunkie

I was in your shoes on Friday, but I went with MDF. I was looking for birch wood around my area and the only birch I was able to locate was 9 ply and I wanted 13 ply. Some people on here are using Arauco and have good results from what I have searched, might want to look into that aswell. Goodluck!


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## radarcontact

For HD applications, I have always used MDF, braced and doubled at the baffle. Someone said earlier that it's wood pieces and glue, not true (they may be thinking of particle or chip-board -- don't use those).

[WIKI=Medium-density fibreboard (MDF) is an engineered wood product formed by breaking down hardwood or softwood residuals into wood fibres, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure.[1] MDF is denser than plywood. It is made up of separated fibres, but can be used as a building material similar in application to plywood. It is stronger and much more dense than normal particle board.]

Anyway, there are techniques you can use to make MDF solid as a rock. It paints perfectly. Smooth as hell. Easily routed, etc.

If you DO use plywood, here are a couple tricks. 
-When you run plywood across the table saw, always run the "pretty" side up (bad side to table top).
-Run your saw blade all the way up! Contrary to the "one tooth rule", this will significantly reduce edge splintering.
-To further reduce edge splintering, put two layers of good quality masking tape where you about to cut, mark or position your piece, and then cut. When you remove the tape, it'll most likely be very clean.
-I have gone as far as to make a 1-3 diluted Elmer's white glue wash, and paint the edges of the plywood (then let dry for an hour) before sanding. (helps with edge splintering from the sander at hard edges)

This is my home entertainment center that I designed and built last year, it's primarily birch plywood. The large black squares you see on either side of the components are 12" subs...those are encased in MDF, THEN surrounded by the birch for aesthetics.










(Funny, the picture is over a year old, but the TV headline could be current from this morning, huh? lol Some things never change!)

--Radar


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## captainscarlett

Thnaks for the tips. For the time being as I don't have a workshop, or garage to work from, i'm going to have to get a timber merchant to cut whatever wood I need. Tday I'm going to ask various merchants if they can cut at angles, mostly fror 45's but also for more complex, or tapered cuts. 

the cost for me isn't an issue, I'll pay for quality, but when i do get my own tools, I'l practice on MDF then move onto Ply.


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## NRA4ever

I use 13 ply birch plywood on my own sub boxes. My customers want MDF. I want to try Avantech flooring on my next box. Its dense,strong & has no formaldehyde in it. It should work good & its $27.00 a sheet


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## minbari

Jonny Hotnuts said:


> Medite and Medex are superior to standard MDF for building sub boxes in every respect.
> 
> ~JH


"medite" is just a brand name for MDF. that like saying that a skill saw is Superior to a circular saw.


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## captainscarlett

NRA4ever said:


> I use 13 ply birch plywood on my own sub boxes. My customers want MDF. I want to try Avantech flooring on my next box. Its dense,strong & has no formaldehyde in it. It should work good & its $27.00 a sheet


I spoke t a collegue at work today after finding out he's a trained carpenter. His view is what the view of all carpeters I've asked, including my bro-in-law, who has a £12,000 table saw (flooring biz). 

They all say use Ply, that for my application, ply has better dampening than MDF, is stronger, and looks better. My friend Dave said, splintering shouldn't be a big issue to worry about. I'll talk to him more tomorrow.


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## stochastic

Out of curitosity has anyone tried using HDF (High Density Fiberboard) for a project instead of the much more common MDF (Medium Density Fiberboard)? I know it exists and have read a little about it in some box design books.


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## BoomHz

In my opinion the quality of MDF is waaay more degraded than what it used to be and the price ain't gettin no better. You add to it the fact that i live in AK where the birch is no more than 5 bucks more.......yeeeey Birch!!


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## NRA4ever

You can get 13 ply in fir also. Its just as strong but it doesn't stain well. I use it inside my cabinets for the drawer units. I dovetail the joints & it works good. I hate MDF. I've grown allergic to it. If I use it much I get headaches & skin rash. Its the formaldehyde.It also is hard to control MDF dust. I can cut any other type of wood & the dust catchers get the dust. Cut MDF all day & your shop will have dust everywhere.


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## captainscarlett

BoomHz said:


> In my opinion the quality of MDF is waaay more degraded than what it used to be and the price ain't gettin no better. You add to it the fact that i live in AK where the birch is no more than 5 bucks more.......yeeeey Birch!!


5 bucks more ... sometimes ... jsut sometimes I wish I lived somewhere other than the UK. We pay thrught the nose for everything ...


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## minbari

stochastic said:


> Out of curitosity has anyone tried using HDF (High Density Fiberboard) for a project instead of the much more common MDF (Medium Density Fiberboard)? I know it exists and have read a little about it in some box design books.


it does exsist, but it is expsencive, heavy and actually pretty hard to find.


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## stochastic

Here is a wonderful explanation of the resonance differences in Baltic Birch compared to MDF, solid oak, and Aircraft Aluminum Wilson Audio: Authentic Excellence: Materials


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## captainscarlett

minbari said:


> it does exsist, but it is expsencive, heavy and actually pretty hard to find.


The only application i can find about HDF is for flooring and it's usually pretty thin. 

3.2mm HDF
Hdf Sheet, Hdf Sheet Manufacturers, Hdf Sheet Suppliers 
MDF and HDF - YouTube


My friend said to me: your worry about birch ply splintering 'shouldn't' be a reason not to use it. Its much stronger, and the finish is better than MDF and resonance is better than MDF.


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## stochastic

HDF is something I've only read about and my local specialty wood store that regularly stocks wood like purple heart, wenge, ebony, rosewood, zebrawood etc... responded with "We'd have to order that in."

Captainscarlett, in that second link of yours there were a number of HDF sheets available in 25mm or 30mm thicknesses. I'm pretty sure that'd be more than enough for even the largest of subwoofer enclosures - though one could always glue two sheets together if a 60mm baffle is needed.


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## NRA4ever

I bought a sheet of avantech flooring for my next box. Its almost as heavy as MDF. Its dense very flat & only $25 a sheet. It should work good. No formaldehyde in it. It looks like OSB but its smooth & much denser than OSB. I'll post my opinion when I start using it.


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## adrenalinejunkie

NRA4ever said:


> I bought a sheet of avantech flooring for my next box. Its almost as heavy as MDF. Its dense very flat & only $25 a sheet. It should work good. No formaldehyde in it. It looks like OSB but its smooth & much denser than OSB. I'll post my opinion when I start using it.



Keep us posted.


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## captainscarlett

NRA4ever said:


> I bought a sheet of avantech flooring for my next box. Its almost as heavy as MDF. Its dense very flat & only $25 a sheet. It should work good. No formaldehyde in it. It looks like OSB but its smooth & much denser than OSB. I'll post my opinion when I start using it.


get some pictures of the build .. that'll be interesting.


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## Godsmack

First time I've heard of someone looking at using flooring for a box.



J


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## hondalover

It isn't flooring per se, it is sub floor material- engineered plywood. Should work well. Looking at the Wilson site, MDF appears a poor choice for mid bass, but the graph in the 20-100 range where most of us ask our boxes to work looks like their secret stuff. I would think the subfloor being engineered should have the approximately same resonance as MDF. The only advantage over MDF is screw holding, but I doubt it is that much better, as a hobbiest woodworker I have experience with both. Screws are only used for the speakers, and most back up with T-nuts and the input connectors, what 8-12 screws? I would imagine that the waterproof coating on the flooring would dull router blades quicker, negating further the advantages. Just some food for thought.


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## rxh0272

captainscarlett said:


> I've been adviced to use birch for subwoofer enclosures. I just need to hear arguements for/against using either birch or MDF.
> 
> Does Birch splinter easily? Is it harder to work with?


I live in Philly. 
When I used MDF, it works well, but doesn't last long. Snow, ice, 18 degrees winter 98 degrees summer. Birch is better, in this regard, in my opinion. Also, Birch has a different sound to it.


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## Niebur3

Thread only 9 years old.


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## Holmz

rxh0272 said:


> I live in Philly.
> When I used MDF, it works well, but doesn't last long. Snow, ice, 18 degrees winter 98 degrees summer. Birch is better, in this regard, in my opinion. Also, Birch has a different sound to it.


Is that part on the "Lasts longer" opinion or fact?


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## rxh0272

Holmz said:


> Is that part on the "Lasts longer" opinion or fact?


Opinion, based on my experience.


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## rxh0272

Niebur3 said:


> Thread only 9 years old.


well you never know who will find it and read it, just like I did. Actually, someone referenced this discussion in another discussion.


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## Holmz

If you have seen the MDF not last as long a birch with snow and water damage, then how could you make it go from an opinion to become a fact?


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## rxh0272

Holmz said:


> If you have seen the MDF not last as long a birch with snow and water damage, then how could you make it go from an opinion to become a fact?


Inherent in my response is that such is my opinion, unless I am making references, etc.
If I come on here and say chocolate ice cream is the best ice cream, do I need to prove it?


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## Holmz

rxh0272 said:


> Inherent in my response is that such is my opinion, unless I am making references, etc.
> If I come on here and say chocolate ice cream is the best ice cream, do I need to prove it?


No but when you can say that the "chocolate ice cream is darker than vanilla but that is only <your> opinion"... That is minimising something that seems like a fact.
I'll drop it, but that birch plywood water resisence seems more like a fact IMO. Even then
plywood is recommended to be sealed in order to be more waterproof.


Some other facts:

MDF is more thermally stabile.
MDF is more easily worked with a router.
MDF has smoother edges
MDF has hIgher desity
(Resonance and dampening??)
Plywood has literally be around since the Mesopotamian days.
Plywood is stronger.
Stiffness (Unsure, but MDF may win??)
MDF is hydroscopic and sucks up water, and when it gets wetting swells.

There are a lot of benefits of MDF.
Maybe it needs some layers of varnish, sealer, or fibreglass?

Fibreglass, and metal, also have a place in that cars usually are volume/space limited.


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## Niebur3

Not sure too many subwoofer enclosures are exposed to water.


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## Holmz

Niebur3 said:


> Not sure too many subwoofer enclosures are exposed to water.


You're probably right, but chucking a snowboard in the back, or on a 4x4... Well there would be some people that would probably be a factor for.

I am thinking of going to a blow through sub... So it seems like would a factor there.


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## dumdum

That’s 12mm very good quality birch ply, 9 layers so I expect 13 layers in a good 18mm birchply, one of the guys over here did a very technical test with Far Eastern ply (it wasn’t birch anyway) vs mdf, basically 25kg bags placed on a single point on the centre of the span of a piece of Far Eastern ply vs the same on mdf, the mdf sagged 2 times as much, for stiffness birch will never be beaten by mdf, and do we want a flexing box or a stiff one? I know what I want and always use birch, I even use 12mm as much as possible for dash enclosures and brace them well


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## dumdum

I should add this wasn’t proper birch ply, but normal Far Eastern ply from his local builders merchants, I would think that 18mm birch would be more like the 25mm standard stuff he used... not so technical test, but shows how poor mdf is for boxes

Credit goes to Marcos Barnes of propper droppers fame in the U.K. 👍🏼


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## Holmz

On the otherhand option of MDF in Pheonix makes sense as an opinion.
And water resistant in potyant makes sense as an option for Portland or Seattle.
And fibreglass or metal for some other bespoke situation?


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## dumdum

Holmz said:


> On the otherhand option of MDF in Pheonix makes sense as an opinion.
> And water resistant in potyant makes sense as an option for Portland or Seattle.
> And fibreglass or metal for some other bespoke situation?


It still doesn’t make mdf better than ply as an enclosure material...


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