Thx bedrock602, I've never seen anything over 8 ply at Lowes or Home depot.....
and it was indeed total junk.... and priced over 2x what I could russian birch for...(pre war)
My cabinet shop has proprietary birch (Vietnamese i think) , i'm trying out now.
11-ply 3/4" if you count the paper thin outer layers...
we'll see ......
and it was indeed total junk.... and priced over 2x what I could russian birch for...(pre war)
My cabinet shop has proprietary birch (Vietnamese i think) , i'm trying out now.
11-ply 3/4" if you count the paper thin outer layers...
we'll see ......
Thanks, I have a tame cabinet maker who has an account with Lathams! A few years ago I used poplar ply from Jewson which was extremely good quality and very fairly priced - not sure what prices are like today though...
Not at all a criticism, just trying to understand. When I think of "damped", I think either in terms of anelastic attenuation in which energy is "lost" to work or a reduction in the resonance frequency. Stiffness works in the opposite direction -- higher stiffness typically reduces anelastic attenuation and raises the resonance frequency. Reducing effective system "stiffness" is kind of what sandwich construction with soft layers attempts to do.
In the US, I have found two general types of plywood which are almost as good as the hard-to-find baltic birch.
The first is normal 3/4" cabinet grade plywood. This product has (typically) 5 internal plies of popular, and 2 outer plies of hardwood. The outer veneer plies are cosmetically very nice. Typically it is made in Canada or the US.
This plywood is not as stiff as BB, but it also lower density, and my rough comparison suggests that the stiffness to weight ratio of cabinet grade plywood is similar to BB. All else being equal, stiffness to weight ratio drives the structural resonance frequency.
Screw holding capability of this plywood is not as good as BB, but it is good enough. I never use threaded inserts or T-nuts when installing drivers, I just screw directly into the wood. If screw threads get worn out, the hole can be filled with epoxy and re-drilled.
The exposed edge is not really nice enough to be a decorative edge, so this material will need a way of hiding or covering the edges.
I have found the internal plies to be nearly void free. The only plywood I have ever worked with that was truly completely void free was the old "true Baltic Birch" which came from Finland before the fall of the USSR. The Russian stuff is good, but not as good as the Finnish plywood. So I would rate the cabinet grade plywood to be about equal to modern Russian BB in terms of internal voids.
I buy from a hardwood lumber shop. Sometimes this kind of plywood is available from the big box stores (lowes, home depot, menards). Unfortunately, it is often inferior to the product sold at the hardwood lumber shop.
The second type of alternate is 3/4" marine plywood. This is 5 plies of Douglas fir. It is an exterior grade plywood, and it is void free. Douglas fir is a strong wood, so screw holding capability is excellent. This plywood is much more dense than popular core plywood, but not quite as dense as BB.
Cosmetically, this plywood must be painted or veneered. The rotary cut douglas fir plies are selected for strength and integrity, not cosmetics. Douglas Fir is a challenging wood to stain or to apply a clear finish onto, and I have never seen it done well. It can splinter badly when cut across the grain.
j.
The first is normal 3/4" cabinet grade plywood. This product has (typically) 5 internal plies of popular, and 2 outer plies of hardwood. The outer veneer plies are cosmetically very nice. Typically it is made in Canada or the US.
This plywood is not as stiff as BB, but it also lower density, and my rough comparison suggests that the stiffness to weight ratio of cabinet grade plywood is similar to BB. All else being equal, stiffness to weight ratio drives the structural resonance frequency.
Screw holding capability of this plywood is not as good as BB, but it is good enough. I never use threaded inserts or T-nuts when installing drivers, I just screw directly into the wood. If screw threads get worn out, the hole can be filled with epoxy and re-drilled.
The exposed edge is not really nice enough to be a decorative edge, so this material will need a way of hiding or covering the edges.
I have found the internal plies to be nearly void free. The only plywood I have ever worked with that was truly completely void free was the old "true Baltic Birch" which came from Finland before the fall of the USSR. The Russian stuff is good, but not as good as the Finnish plywood. So I would rate the cabinet grade plywood to be about equal to modern Russian BB in terms of internal voids.
I buy from a hardwood lumber shop. Sometimes this kind of plywood is available from the big box stores (lowes, home depot, menards). Unfortunately, it is often inferior to the product sold at the hardwood lumber shop.
The second type of alternate is 3/4" marine plywood. This is 5 plies of Douglas fir. It is an exterior grade plywood, and it is void free. Douglas fir is a strong wood, so screw holding capability is excellent. This plywood is much more dense than popular core plywood, but not quite as dense as BB.
Cosmetically, this plywood must be painted or veneered. The rotary cut douglas fir plies are selected for strength and integrity, not cosmetics. Douglas Fir is a challenging wood to stain or to apply a clear finish onto, and I have never seen it done well. It can splinter badly when cut across the grain.
j.
yeah I've used some stuff from lowes that had the highest ply count, it's really light and honestly kinda terrible. The veneer is basically what looks to be some sort of brushed on texture, you'll sand through it by looking at it.
My local big box menards carries A grade stuff but you have to order it and it's expensive. There's a shop two hours away that says they have 5x5 BB sheets for $65 but we'll see how up to date that is.
I've been finding it's almost not worth the hassle of making sure ply edges don't tear out and being delicate with the faces in general to not be worth it compared to just veneering MDF. I find MDF to be far more solid and rigid of a material, knock test is no comparison, the MDF is always much more damped.
My local big box menards carries A grade stuff but you have to order it and it's expensive. There's a shop two hours away that says they have 5x5 BB sheets for $65 but we'll see how up to date that is.
I've been finding it's almost not worth the hassle of making sure ply edges don't tear out and being delicate with the faces in general to not be worth it compared to just veneering MDF. I find MDF to be far more solid and rigid of a material, knock test is no comparison, the MDF is always much more damped.
I haven't tried any marine grade yet. Want to.....
I have tried high quality cabinet grade several times, from wholesale cabinet shop suppliers....large national houses with good selection.
None of it has come close to standard russian baltic-birch, (which i think is what is generally labeled as baltic birch)
I guess a lot of what works, depends on the size of the speaker and drivers.
Ime, baltic-birch or whatever becomes its acknowledged substitute, is the go-to for larger boxes.
I have tried high quality cabinet grade several times, from wholesale cabinet shop suppliers....large national houses with good selection.
None of it has come close to standard russian baltic-birch, (which i think is what is generally labeled as baltic birch)
I guess a lot of what works, depends on the size of the speaker and drivers.
Ime, baltic-birch or whatever becomes its acknowledged substitute, is the go-to for larger boxes.
I think the marina grade is what we call meranti (plywood) here?
It's really stiff and hard, but lighter than birch.
The price difference isn't that much different here.
You only really need a surface layer, because it can splinter pretty nasty.
The finish is also quite rough, not great for stains or varnishes.
So an hybrid is quite nice.
Just use some thin layer of birch (3-6mm or so) as a finishing layer of whatever else cheaper material you're gonna use.
Or just use veneer.
It's really stiff and hard, but lighter than birch.
The price difference isn't that much different here.
You only really need a surface layer, because it can splinter pretty nasty.
The finish is also quite rough, not great for stains or varnishes.
So an hybrid is quite nice.
Just use some thin layer of birch (3-6mm or so) as a finishing layer of whatever else cheaper material you're gonna use.
Or just use veneer.
There is always Apple Ply from States Industries.
https://www.statesind.com/apple-ply/
Sourcing is the issue, typically. Baltic birch was ubiquitous, until it wasn't. Apple Ply has been around a long time, they just haven't had a lot of luck with market penetration. Might have something to do with what they're able to achieve with wholesale pricing. I've always suspected the Baltic birch plywood is pretty inexpensive wholesale, especially when you consider it is shipped half way around the globe (for those of us in the U.S.).
I wonder what Troels Gravesen is doing, that guy looks to use quite a bit of Baltic birch plywood.
https://www.statesind.com/apple-ply/
Sourcing is the issue, typically. Baltic birch was ubiquitous, until it wasn't. Apple Ply has been around a long time, they just haven't had a lot of luck with market penetration. Might have something to do with what they're able to achieve with wholesale pricing. I've always suspected the Baltic birch plywood is pretty inexpensive wholesale, especially when you consider it is shipped half way around the globe (for those of us in the U.S.).
I wonder what Troels Gravesen is doing, that guy looks to use quite a bit of Baltic birch plywood.
Yes you'd think!
It's not all Russian by any means.
10% came from Russia.
Sources: The Baltic birch tree originates in the Baltic States – Estonia, Latvia and Lithuania. Baltic birch plywood is primarily produced in Finland and Russia.
Perhaps it is production that's been hit most?
My timber merchant can still get 18mm, 24mm, 30mm (and thinner), in nice quality and yes a bit pricier than before, but not the prices some are quoting!
It's not all Russian by any means.
10% came from Russia.
Sources: The Baltic birch tree originates in the Baltic States – Estonia, Latvia and Lithuania. Baltic birch plywood is primarily produced in Finland and Russia.
Perhaps it is production that's been hit most?
My timber merchant can still get 18mm, 24mm, 30mm (and thinner), in nice quality and yes a bit pricier than before, but not the prices some are quoting!
The cabinet shops I buy from tell me russian baltic birch quality comes from both the manufacturing process and the particular birch species.
I've kept my garage shop stocked with all sizes of 5x5 sheets.....18, 15, 12, 9, 6 and even 3mm ..... for an average cost per sheet of under $30.
Bet I've gone thru nearly 100 sheets, as I use it for all kinds of household cabinetry projects too. I simply love the stuff.
Damn war....here in the US, it's all about import barriers i think.
I've kept my garage shop stocked with all sizes of 5x5 sheets.....18, 15, 12, 9, 6 and even 3mm ..... for an average cost per sheet of under $30.
Bet I've gone thru nearly 100 sheets, as I use it for all kinds of household cabinetry projects too. I simply love the stuff.
Damn war....here in the US, it's all about import barriers i think.
I have had very nice results applying veneer over marine plywood. I have applied walnut, cherry, and maple veneer. I sanded the plywood smooth with 100 grit paper, and then applied PSA "peel and stick" veneer. Very nice results.
Of course nothing is quite as good as BB plywood. But in these times, we do the best we can with what we have.
The cabinet grade plywood seems durable enough for a home environment, it is the go-to material for kitchen cabinets and a lot of furniture. I am skeptical it would be durable enough for a professional sound reinforcement speaker.
Of course nothing is quite as good as BB plywood. But in these times, we do the best we can with what we have.
The cabinet grade plywood seems durable enough for a home environment, it is the go-to material for kitchen cabinets and a lot of furniture. I am skeptical it would be durable enough for a professional sound reinforcement speaker.
Hi Jim, yep i think you're right with those assessments.
I don't care at all about professional sound reinforcement, but I do like a good strong box that's plenty durable.
You know, another big thing about russian BB's popularity, is for me at least, it's been less expensive than cabinet grade ply. (in the eastern US)
My thinking has been, why use anything else if it's cheapest ?
Most cabinet grade I've encountered has one or two sides finished. Which dramatically raises prices. Or close to blemish free, if unfinished.
Hells bells, the most suitable 5/8" i can currently find for build a large 'syn11' unity-type horn, has one finished side that i have to sand off to use duratex ...yikes and lol...
Your statement is too broad and categorical. There is a wide variety of materials and techniques used in "high end" speakers... that is assuming we can even get agreement on what "high end" actually is.
Some highly regarded speakers are made from MDF... some are made from plywood... some are made from aluminum... some from composite (fiberglass and/or carbon fiber).