Why Birch Ply for speakers?

[Beechnut]

Does Birch Ply have an acoustic property about it or is it a weight/look/price combination. Or combination of all?

Could you get the same acoustic properties out of oak, mahogony, if you weren't worried about cost, weight etc....

[Guest " "]

the heavier woods would resonate less...birch ply is just a fav, other cabinet grade plys would work well also....construction grade plys is what you want to stay away from. on a 10" panel or table saw...use a finish quality blade to cut...90T min, but 120T if you can find one.

[MechMan]

I think it's a best bang for the buck kinda deal...Solid wood more money, mdf too heavy.

[djk]

[Chris A]

Could you get the same acoustic properties out of oak, mahogony, if you weren't worried about cost, weight etc.

I think that the answer is a qualified "no": MDF is probably the best in terms of freedom from interfering resonances, but its structural properties (especially chipping and lack of threaded connection strength after assembly/disassembly/reassembly) is inferior to the multiple lamination ply--like Baltic birch (picture above). MDF is also very heavy.

Of course, you could go with hogged-out structural or cast aluminum alloy - like the Magico line of speakers...[8-)]

Chris

[mustang guy]

Steinway piano makes the rims of their piano's from layered hard rock maple.

I have also heard most piano's are basically maple with veneer.

Would maple be the best material domestically?

[djk]

I think the best available product in the USA is Appleply (pictured above)

Alderwood and birch cores with no voids, and maple faces (other veneer is available).

http://www.statesind.com/prod/ind_2a2.html

[Beechnut]

So ply does a better job of resonance than a hardwood.

Also a really good illustration of how thin veneer is up above. Thank you for that.

[DavidF]

You want to shoot for stiffness or mass, or both, to

manipulate the resonance frequency. Plywood, by nature of the lamination, is

very stiff compared to solid woods or most chipboard materials. MDF can be very

dense and thus gains mass but in my experience is not all that stiff. Lower

grade plywood will have significant voids that create pockets in the plys. Bad

for stiffness and resonance diffusion. Higher grade ply will be consistent in

density and bonding in the layers. Marine grade birch being a good example. I

like to use MDF because is less expensive and I can stiffen it up with bracing.

I haven’t built large panel enclosures but I would consider stiff ply for such

an application.

[JJkizak]

Maybe PWK just liked birch.

JJK

[dtel]

I had used some plywood from home depot, Red Oak 3/4" $50 a sheet. I liked working with it, very few small voids, like 3 or 4 really small voids found while cutting up 12 sheets. I did pick through a few different sheets at the store to get all good edges and grains I liked.

They had one sheet that had a really wild grain but I didn't have anything that would only take one sheet, I almost bought it any way but was spending enough already.

[Groomlakearea51]

MDF was not available when PWK started. "Quality MDF" was an oxymoron until not too long ago. MDF is, in substance, much cheaper than good quality plywood. MDFs "sonic" characteristics lend themselves to speaker cabinet conctruction, but the drawback is brittleness, prone to radical moisture damage, etc. The primary reason it's used is as stated, cheaper, and also easier to cut with CNC routers which are what manufacturers use to make boxes..... Good baltic (Karelian, or Russian birch) plywood is expensive by comparison.

[H]

[Rivernuggets]

Steinway piano makes the rims of their piano's from layered hard rock maple.

Depending on the model made, 10-17 laminations.

You can get 4' x 8' sheets of 13 ply Baltic Birch at Menards.

[OO1]

BIRCH IS STILL THE BEST - period -

[Chris A]

Very old thread...

[Fleawatt]

KLF-20's. The cabinets were black and trashed.  Made good candidates for a re-build with Baltic Birch.

 

[OO1]

Maybe PWK just liked birch.

 

 

as a matter of fact , he did -

[Arash]

I always use Finnforest, Koskisen, Wisa or Sveza plywood. all are Finland Birch except Sveza which is made in Russia and Kazakhstan.

we buy Sveza 3/4" (13 ply) 48" x 96" for ~55USD/sheet

Edited January 19, 2015 by Arash

[OO1]

I always use Finnforest, Koskisen, Wisa or Sveza plywood. all are Finland Birch except Sveza which is made in Russia and Kazakhstan.

we buy Sveza 3/4" (13 ply) 48" x 96" for ~55USD/sheet

  great quality for sure

[Taz]

Very old thread...

 

Found a lot of good info from old threads. 

 

Heck some of the old threads are still new to me.