Birch plywood now available in India

[tcpip]

... when listening to music, I theorize that the effect of bracing might be inaudible.

In my experience, the most dramatic effect of an inert enclosure is a sharpening of the soundstage and the listener's ability to locate sound sources. It may have little or no impact on the tonal quality of the sound, other than in pathological cases of poor enclosures which really resonate loudly at certain frequencies.

 

[jls001]

I'll eat the T.O.I. The Sunday edition with the supplements.

Saturday editions are known to be crunchier

 

[keith_correa]

...other than in pathological cases of poor enclosures which really resonate loudly at certain frequencies.

A la the enclosures that are thin walled and impart a certain "character" to the sound? Yes, I agree.

The "knuckle test" - IMO this is fundamentally flawed. One is directly exciting a surface that is not directly excited by a driver and its associated behavioural characteristics in an enclosure. A more realistic "test" would be to excite the wall with the ball of your palm - this is closer to reality, actually more than real.
And if you mass load the inner walls and damp the back waves adequately, the effect of bracing is even more redundant.
Example: One can layer thin floppy silicone sheets or craft foam sheets on all the inner walls and if these are further layered by fibreglass or Rockwool batts or even convoluted open cell foam, IMO just plain window braces are sufficient bracing. Anything more is over engineering and over thinking.

Note: I don't necessarily practice what I preach each time. If I had the opportunity to do a lot of builds, maybe I would.

 

[Hiten]

what about the bbc thin wall philosphy used by harbeth etc?
http://downloads.bbc.co.uk/rd/pubs/reports/1977-03.pdf

I dont know where but earlier I had posted link of Harbeth's Alan Shaw discussing thin speaker enclosure. It was about tuning the whole enclosure so as to minimize the enclosure effects on SQ.
Regards.

 

[regeHA]

Saturday editions are known to be crunchier

well at least in the UK we do get a free CD now and then.

Not edible but certainly enjoyable.

I've one from PSB and one from Prince that are not available anywhere else.

@tcpip - Thanks for the links to your blog. Interesting reading and well written too.

Not a DIYer and never will be... never blessed with those skills, but still thanks for the write up.

 

[jls001]

This thread has meandered so far away from topic so here's some more:

Rigidness is but one valid philosophy. The thin wall philosophy is equally valid. Proof is in the numerous Harbeths, Spendors, Grahams, etc that are sold every year.

One is free to choose one's "religion" but all I'm saying is that we shouldn't preach that as the only path to sonic nirvana.

 

[keith_correa]

This thread has meandered so far away from topic so here's some more:

Rigidness is but one valid philosophy. The thin wall philosophy is equally valid. Proof is in the numerous Harbeths, Spendors, Grahams, etc that are sold every year.

One is free to choose one's "religion" but all I'm saying is that we shouldn't preach that as the only path to sonic nirvana.

You're right. These, that you mention are carefully crafted right down to the material used and the tuning. Done right - they sound musical. Of course, there's a difference between something sounding musical and accuracy but that is food for another thread.

Now - back to Birch plywood.

 

[shafic]

Today I apporched the importer of the Russian beech ply and visited his authosied stockist m/s Swastik ply n wood, Santacruz west, Mumbai with one of our FM for his Lenco L 75 plinth project.

The Russian beech/birch ply is available in various thicknes from 1.5 mm to 18 mm. The price of 18mm is @Rs 150/- per sq ft. The standard sheet size is 48 = 32 sq ft. He has laser cutting facilities too. Cutting cost will be extra.

Due to my experience as a business man ( children books) I was able to convince him to give some discount for our forum members. One can get discount 10% to 35% depending on the quantity. One can mention Joshua or my name as a reference.

I don't have any COMMERCIAL affiliation with him. I am giving this information for the benefit of the forum members. Dealing with him at your own risk.

Contact person:- Mr. Pranav, mob no is 9619609729

Regards,
Shafic

 

[Thad E Ginathom]

In pictures...

Beech veneer
Birch veneer

Birch Tree
Beech Tree

The google images seem rather biased to the silver birch: it comes with bark of different colours. I have no idea if the veneer of, say, copper birch, is different to that of silver birch.

 

[rajesh srinivas]

MDF is not as rigid as thick, good quality plywood. In other words, MDF has resonances at lower frequencies, all else being equal. Ply therefore makes better bracing material. If there was a way for me to make braces using 12mm glass sheets, I'd opt for that.

You mean MDF is not suitable for building boxes or not suitable for bracing???

If no then How do you justify that plywood is better for bracing then MDF,whereas i havent seen anywhere on net or anyone giving drawback using MDF either for making boxes plus for bracing.

can you elobrate in what you say.

thanks
R/S.

 

[Thad E Ginathom]

Guys... Thank you for the discussion on speaker innards: very interesting. At least it gives a clue what one is paying for in a B&W speaker like that, whether people agree with the design or not.

About the trees...

As per previous post, they are very different. I am not very good on trees or the timber from them, but one thing you can see straight away from the google images is that the Birch is a fairly slim tree, whereas the Beech is potentially massive. I don't know if Beech is much used for veneers, but you certainly wouldn't get much in the way of planks out of a Birch.

On marine ply, by the way.... years back I used to think it was all made from mahogany and the like. Probably the only marine ply I'd seen had mahogany veneers on the surfaces. A carpenter friend of mine, with a strong interest in boats, told me that marine ply is not so much about the wood as about the glue! Yes, it must be strong and of even density (no voids) but it must not de-laminate when wet. Not even when repeatedly wet/dry.

 

[keith_correa]

...but you certainly wouldn't get much in the way of planks out of a Birch.

Oh, you'll get planks but just not wide enough. Besides, you don't need planks for making plywood, it's made up of rotary cut veneer sheets.

 

[Thad E Ginathom]

Yes, Keith: I know what plywood is. the secret is in the word "ply" :lol:

I suppose I meant to say that, should one choose solid, rather than ply, birch is not going to be wide enough.

Life's a beech, eh? :lol:

 

[keith_correa]

Life's a beech, eh? :lol:

Yes, and then you die!

 

[mhtplsh]

Birch plywood can be bought cheaper if you buy in the city by making group & buy in bulk. Minimum 10~15% difference will be there.

 

[GeorgeO]

Rajesh

Tarun says that it's relatively more rigid, and therefore more suitable for bracing. I've used MDF for bracing( and enclosures) multiple times and its worked fine for me.

 

[GeorgeO]

Birch ply wood

I bought some 16mm birch ply from Eximcorp recently, for building some speaker enclosures. Service and email responses from Shri BK Lunia were excellent. He sent me a proforma invoice and upon remitting payment by NEFT, shipment was immediate. The material itself is very high quality stuff and the carpenter was singing its praises.

 

[tcpip]

Re: Birch ply wood

What are the thicknesses in which it is available? Do they only deliver to B'lore? I'm about to start some projects, and it would be nice to play with this material.

 

[GeorgeO]

Re: Birch ply wood

They deliver in South India from Chennai and I think in other places from their Delhi warehouse. They have a range of thicknesses, ranging from 4, 6,8,9, 12,15,16,18,21,24 mm, I believe. If you ask him he will provide specs and prices.

 

[manniraj]

Re: Birch ply wood

I bought some 16mm birch ply from Eximcorp recently, for building some speaker enclosures. Service and email responses from Shri BK Lunia were excellent. He sent me a proforma invoice and upon remitting payment by NEFT, shipment was immediate. The material itself is very high quality stuff and the carpenter was singing its praises.

Can you share the cost of 8x4 sheet for 16mm? Also did they ship from Chennai then the cost would have gone up because of the shipping right.