Hybrid plys are available. They wholesale well over $100 per sheet so retail could easily be double. Office furniture industry uses alot of this material. You could buy solid core 1-3/8" (1/4ply w PB core) doors slabs at about $50 and use this for 5 sides, or 3 and 3/4 for the rest. Mixing thickness will also benefit damping. It'd be heavy and would need a large saw to seperate. Really DW is right about the cabinets own res being higher than what the woofer can excite. You really just want ridgidity, and plywood is best here. MDF got popular because of cost. Trees got smaller, we cut trees and panels faster. Back when mdf got going ALL spkrs were plywood with NO reservation. Only in consumer grade consumables did sawdust panels become popular. The very best quality will be playwood or solid wood construction.
TC
TC
Some of the suggestions here sound like a fair amount of unecessary cost and effort IMO. If you are building large PA cabinets then plywood makes sense. But for a home sub I'd stick to MDF. Use plenty of bracing and either use 1" thick or double layer 3/4" if you would like it to be very solid. You can also use more bracing than shown on the Adire recommendations. This can get a stiffer cabinet with very little extra weight. If weight becomes an issue then wheels might be a good idea. I suppose this would be the main reason you might consider ply, but is it really lighter for the same result?
Wouldn't MDF be more than ply if...
If you're looking for a real wood veneer finish, isn't MDF going to come out more expensive once you buy the veneer sheet and adhesive, as compared to a nice veneer plywood? Now granted, you can do things with separate veneer that you couldn't do with pre-veneered plywood. If you just want a painted box, then sure, I bet MDF is less expensive.
As for weight, I've seen as much as a 40% reduction for plywood as compared to MDF. That's not insignificant. It could mean the difference between a cabinet that one person can carry or one that requires wheels, a hand truck, or an extra person.
Now my cabinet, despite being made of about half 3/4" plywood and half 3/4" particleboard sandwiched to 1/4" hardboard, is still way too heavy. It doesn't even have an amp in the box or a super excursion driver, and still weighs about 130 pounds, so it has casters. Most people don't have a 9.7 cubic foot box, though.
Aaron Gilbert
If you're looking for a real wood veneer finish, isn't MDF going to come out more expensive once you buy the veneer sheet and adhesive, as compared to a nice veneer plywood? Now granted, you can do things with separate veneer that you couldn't do with pre-veneered plywood. If you just want a painted box, then sure, I bet MDF is less expensive.
As for weight, I've seen as much as a 40% reduction for plywood as compared to MDF. That's not insignificant. It could mean the difference between a cabinet that one person can carry or one that requires wheels, a hand truck, or an extra person.
Now my cabinet, despite being made of about half 3/4" plywood and half 3/4" particleboard sandwiched to 1/4" hardboard, is still way too heavy. It doesn't even have an amp in the box or a super excursion driver, and still weighs about 130 pounds, so it has casters. Most people don't have a 9.7 cubic foot box, though.
Aaron Gilbert
Full range enclosures are a complicated beast, with lots of ways to tackle the problems encountered. Sub enclosures are relatively simple, with two primary goals: make the walls stiff enough to lower wall deflection to a point where the walls do not contribute audibly to the sound, and make sure the resonant frequency is above the passband of the sub just in case you fail on the first task.
The only reason I mention the second separately is because there are two ways to achieve the same resonant frequency for a given size panel - light and relatively flexible, or heavy and relatively stiff. Just make sure the stiffness is there, and then go for the lightest solution possible.
For sub enclosures, there are multiple ways to accomplish these simple goals. Use a cheap, decent material like MDF with thick walls and/or plenty of bracing. Or, use a better material like hardwood plywood with thinner walls, less bracing, or both. The damping properties of either MDF or plywood mean practically nothing to a well engineered sub enclosure (but might be very important for full range enclosures).
MDF probably has the cost advantage for a given enclosure design of a desired stiffness/resonant frequency. Workability and ease of finishing nicely could go either way, depending on what type of finish you desire and your skill level. Weight advantage goes to hardwood plywood for a given enclosure size and performance goal.
IMO, regular plywood would work fine for the vast majority of subwoofer applications provided that you use sufficient internal bracing. So long as it is readily available and you are comfortable working with that material, there aren't any "showstopper" reasons why you should not use it without worries.
However, again IMO, it makes the most sense to use hardwood plywood when final cabinet size is crucial. If you are trying to design a small sub, it makes a difference whether your wall thickness is 3/4" or 1-1/4". If finished size isn't that critical, in most cases you might as well just buy a second sheet of MDF and double up on the wall thickness, or add more internal braces.
The only reason I mention the second separately is because there are two ways to achieve the same resonant frequency for a given size panel - light and relatively flexible, or heavy and relatively stiff. Just make sure the stiffness is there, and then go for the lightest solution possible.
For sub enclosures, there are multiple ways to accomplish these simple goals. Use a cheap, decent material like MDF with thick walls and/or plenty of bracing. Or, use a better material like hardwood plywood with thinner walls, less bracing, or both. The damping properties of either MDF or plywood mean practically nothing to a well engineered sub enclosure (but might be very important for full range enclosures).
MDF probably has the cost advantage for a given enclosure design of a desired stiffness/resonant frequency. Workability and ease of finishing nicely could go either way, depending on what type of finish you desire and your skill level. Weight advantage goes to hardwood plywood for a given enclosure size and performance goal.
IMO, regular plywood would work fine for the vast majority of subwoofer applications provided that you use sufficient internal bracing. So long as it is readily available and you are comfortable working with that material, there aren't any "showstopper" reasons why you should not use it without worries.
However, again IMO, it makes the most sense to use hardwood plywood when final cabinet size is crucial. If you are trying to design a small sub, it makes a difference whether your wall thickness is 3/4" or 1-1/4". If finished size isn't that critical, in most cases you might as well just buy a second sheet of MDF and double up on the wall thickness, or add more internal braces.
simon5 said:
If you haven't figured it out yet, the answer to your question is no one has an answer. You're going to have to just make a judgement call based on people's experiences.
You want my opinion?
If you build the cabinet to Adire's specs its highly likely that you wouldn't be able to discern even the slightest difference between an MDF and plywood cabinet.
Re: Wouldn't MDF be more than ply if...
Well, unless you are a wizard at joinery, even pre-veneered ply only saves you the work on a couple of sides. And in my very limited experience, MDF is much nicer substrate to work with than cheap ply because it never chips, it machines very nicely, and is extremely flat. In addition, the benefit of veneering AFTER construction is that gouges, corners, etc can be fixed before applying veneer.
Locally veneer plywood gets perhaps $45 a sheet for the 5-ply, MDF is more like $20. I pay $30 a sheet of oak 10 mil from tapeease. The price difference per finished 4x8 is only 10%, and there is likely to be much less wastage.
aaroncgi said:
Well, unless you are a wizard at joinery, even pre-veneered ply only saves you the work on a couple of sides. And in my very limited experience, MDF is much nicer substrate to work with than cheap ply because it never chips, it machines very nicely, and is extremely flat. In addition, the benefit of veneering AFTER construction is that gouges, corners, etc can be fixed before applying veneer.
Locally veneer plywood gets perhaps $45 a sheet for the 5-ply, MDF is more like $20. I pay $30 a sheet of oak 10 mil from tapeease. The price difference per finished 4x8 is only 10%, and there is likely to be much less wastage.
Re: Re: Wouldn't MDF be more than ply if...
How do you figure it only saves work on two (out of presumably six) sides? You have to apply veneer on all six sides of the MDF, and no sides of the plywood? Of course, if you are thinking you only finish part of the MDF in veneer, with the other sides perhaps painted, I can see it. Though, plywood does add extra steps IF you want to cover the edges.
That said, now that I think about it, as far as cost, it's probably a draw, especially since I have never priced out the cost of veneer. For plywood, if you don't want to see the cut edges, you need to throw in the cost of edge banding and/or solid wood corner trim. I personally don't mind seeing the edges, especially with a thick/dark stain, but know that not everyone likes that look, and it does look a bit less 'commercial'. I want my subwoofers to look as different from a commercial unit as possible, but I'm odd.
As for pricing, that sounds reasonable for veneer plus MDF. I've recently discovered that Home Depot sells a really nice 3/4" maple plywood for only $30 a sheet, though. I'll use that in the future unless I happen to want oak, which is about the $45 you mention. No argument about MDF being easier to machine and not chipping. However, overall easier to work with I think is up for debate, given that it requires a respirator from all the nasty dust that it produces. I agree that plywood does require more attention to detail because you are working with the final surface all along and are not able to cover up mistakes as well.
I think the point to take away from all this though, is that either can make a fine cabinet. The choice to use one or the other really should come down to personal preference in construction and finishing methods. From my perspective, the DIY community for the past many years has been skewed heavily towards MDF as the be-all and end-all of cabinet making materials, with hardly a second thought towards good plywood. As a person who hauls around large speakers and subwoofers every day, I think this is a mistake!
Aaron Gilbert
tiroth said:
How do you figure it only saves work on two (out of presumably six) sides? You have to apply veneer on all six sides of the MDF, and no sides of the plywood? Of course, if you are thinking you only finish part of the MDF in veneer, with the other sides perhaps painted, I can see it. Though, plywood does add extra steps IF you want to cover the edges.
That said, now that I think about it, as far as cost, it's probably a draw, especially since I have never priced out the cost of veneer. For plywood, if you don't want to see the cut edges, you need to throw in the cost of edge banding and/or solid wood corner trim. I personally don't mind seeing the edges, especially with a thick/dark stain, but know that not everyone likes that look, and it does look a bit less 'commercial'. I want my subwoofers to look as different from a commercial unit as possible, but I'm odd.
As for pricing, that sounds reasonable for veneer plus MDF. I've recently discovered that Home Depot sells a really nice 3/4" maple plywood for only $30 a sheet, though. I'll use that in the future unless I happen to want oak, which is about the $45 you mention. No argument about MDF being easier to machine and not chipping. However, overall easier to work with I think is up for debate, given that it requires a respirator from all the nasty dust that it produces. I agree that plywood does require more attention to detail because you are working with the final surface all along and are not able to cover up mistakes as well.
I think the point to take away from all this though, is that either can make a fine cabinet. The choice to use one or the other really should come down to personal preference in construction and finishing methods. From my perspective, the DIY community for the past many years has been skewed heavily towards MDF as the be-all and end-all of cabinet making materials, with hardly a second thought towards good plywood. As a person who hauls around large speakers and subwoofers every day, I think this is a mistake!
Aaron Gilbert
THought I might chuck this post in here since its on the topic of box material.
What are the opinions out there of using just plain pine?
(not ply, not MDF, just solid wood from the tree)
AND...
if there are major irregularities in the thickness of the sides, say if I used a piece of timber that came from the outside of the tree and I didnt dress it and make it all flat, but instead just cleaned it up, accentuating the natural "tree look", will this create any "undesirable" qualities?
Sorry if this is completely ignorant, but Im new to this and was thinking that I'd like to design some eye catching cabinets and just want to see what the world says about it
Cheers
Shaun
What are the opinions out there of using just plain pine?
(not ply, not MDF, just solid wood from the tree)
AND...
if there are major irregularities in the thickness of the sides, say if I used a piece of timber that came from the outside of the tree and I didnt dress it and make it all flat, but instead just cleaned it up, accentuating the natural "tree look", will this create any "undesirable" qualities?
Sorry if this is completely ignorant, but Im new to this and was thinking that I'd like to design some eye catching cabinets and just want to see what the world says about it
Cheers
Shaun
My latest speakers....
Were made out of 2 x 12 lumber on four sides. Really it was just for the heck of it, as I always wanted to try using dimensional lumber. I think it's douglas fir, just the standard stuff at Lowe's, and certainly it took quite a bit of searching the pile to find only the two pieces I needed!
While in some ways it made building the enclosure super simple, since I didn't use any bracing or glue blocks, in most other ways it was way more time consuming. Even discounting the fact that it may warp/split further in the future, I still wouldn't do it again because it took to blasted long to work with! Cutting holes in that stuff takes more than twice as long as 3/4" material, and the rough finish meant I had to spend two yucky hours sanding the things to get them smooth, after another couple hours applying wood filler. Ick. All that said, they did come out really nicely in terms of the finish, given the original condition of the wood, and they are solid as a rock, though certainly ligher than 1.5" of MDF would be. Interestingly, I used 5/16" plywood for the largest panels (drivers are mounted on the 2 x 12), which sounds obscenely thin. One side is glued and screwed to the 2 x 12 frame, the other is just screwed so as to be removeable. The low amount of flex in such thin plywood, especially with an open panel size of 26" x 15", really surprised me.
So the moral of my story is, you CAN build a nice sounding and looking speaker out of real wood. However, I would not suggest using 2 x ** lumber to do it unless you just like to be odd like me. Instead, I'd suggest something like laminated pine boards, or if you want to get really pricey, something like oak or poplar. Sure, it can still warp, but I think on a small bookshelf speaker the problems will be minimal, and the finishing will be a snap. I made a CD holder out of 3/4" solid oak about 15 years ago which has four sides joined together, of a size you might find in a small speaker. There's not a trace of any movement whatsoever, it still looks exactly the same as it did when I first glued it together.
Aaron Gilbert
Were made out of 2 x 12 lumber on four sides. Really it was just for the heck of it, as I always wanted to try using dimensional lumber. I think it's douglas fir, just the standard stuff at Lowe's, and certainly it took quite a bit of searching the pile to find only the two pieces I needed!
While in some ways it made building the enclosure super simple, since I didn't use any bracing or glue blocks, in most other ways it was way more time consuming. Even discounting the fact that it may warp/split further in the future, I still wouldn't do it again because it took to blasted long to work with! Cutting holes in that stuff takes more than twice as long as 3/4" material, and the rough finish meant I had to spend two yucky hours sanding the things to get them smooth, after another couple hours applying wood filler. Ick. All that said, they did come out really nicely in terms of the finish, given the original condition of the wood, and they are solid as a rock, though certainly ligher than 1.5" of MDF would be. Interestingly, I used 5/16" plywood for the largest panels (drivers are mounted on the 2 x 12), which sounds obscenely thin. One side is glued and screwed to the 2 x 12 frame, the other is just screwed so as to be removeable. The low amount of flex in such thin plywood, especially with an open panel size of 26" x 15", really surprised me.
So the moral of my story is, you CAN build a nice sounding and looking speaker out of real wood. However, I would not suggest using 2 x ** lumber to do it unless you just like to be odd like me.
Instead, I'd suggest something like laminated pine boards, or if you want to get really pricey, something like oak or poplar. Sure, it can still warp, but I think on a small bookshelf speaker the problems will be minimal, and the finishing will be a snap. I made a CD holder out of 3/4" solid oak about 15 years ago which has four sides joined together, of a size you might find in a small speaker. There's not a trace of any movement whatsoever, it still looks exactly the same as it did when I first glued it together. Aaron Gilbert
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