Here at 3 Square Audio we use only two premium quality materials to construct all of our speakers and our furniture.
These materials have been chosen over all others for their superior quality, performance and ability to be crafted into first class products. Most of our products can be made entirely from one or the other product or if required in a combination of the two. This affords us a wide range of colour and style options to contrast or compliment your own style as you wish.
The first material we chose to use was Baltic Birch Plywood. This is the highest quality plywood available, made up of very thin alternating layers of slow grown birch hardwood, grown in the Baltic countries around the Baltic sea. It possesses several useful properties for our needs, these include tensile strength, high mass and excellent damping properties. We use this material in its natural state, making good use of the looks that its distinctive edge affords.
Our second material is called Valchromat. This is the highest quality and form of MDF available. Unlike normal MDF it is not made of dust but wood particles. These particles have been dyed to the various colours that the board is available in, giving it colour right through the board. It is also waterproof and has tensile strength. One of its most significant benefits for us is its mass, at 16% more than Baltic Birch Ply it affords our products great solidity and even better damping characteristics.
Baltic Birch Plywood
Baltic Birch plywood is a top-class plywood with good hardness, strength and stability.
These attributes are important to our use in furniture and loudspeaker cabinets but are also
the main reason why the plywood is expensive in the market place. There are cheaper but
inferior materials we could utilise but that would defeat the objectives that we are striving
Traditional plywood is made up of veneers, generally quite thick with the cores made of softer
materials than the face and with internal voids. All layers of Baltic Birch are actually veneers
of Birch. They tend to have a thick outer veneer and a void free core made up of 1.5mm
veneers. As a result, you get clean dadoes, rabbets, dovetails, mitres and fingers for strong,
and when appropriate, great looking joints. As the core is free of voids, your joinery also
won’t suffer from glue starvation—they’ll get 100% glue coverage. Anything you build out of
Baltic Birch should last a good, long time.
The sheets are made of many more layers and being cross-banded layers of approximately
1.5 mm thick Birch the sheets balanced, which promises a flatter product.
One of the fortunate benefits to Baltic Birch, too, is that you can leave the edges exposed if
you like the look.
Baltic Birch Plywood comes in numerous thicknesses and we make use of most of them
The sizes are:
3 mm (3 plies)
6 mm (5 plies)
9 mm (7 plies)
12 mm (9 plies)
15mm (11 plies)
18 mm (13 plies)
21mm (15 plies)
24mm (17 plies)
30mm (21 plies)
Baltic Birch Plywood also comes in several grades. We only use the better grades as we
require an attractive finish to the wood and anything that we make from it. The grading for
Baltic Birch is established by the Russian intergovernmental standard GOST 3916.1-96.
Grading is given as the two outer faces of the plywood, in the format of front/back. For
instance, Baltic Birch with a “B/BB” grade would have a B grade front ply, and a BB grade
back ply, where B is slightly better than BB.
The grades are:
A: Nearly perfect and flawless face veneer ply. This grade is no longer available
commercially. (Also designated grade “E” according to GOST 3916.1-96.)
B: Generally uniform light colour, with no plugs, or open cracks/splits. A limited amount of
pin knots, and minor colour inconsistencies are allowed. (Also designated grade “I”
according to GOST 3916.1-96.)
BB: Generally uniform colour, though colour variations/stains are allowed. Limited number
of plugs, cracks/splits, and unlimited amount of pin knots allowed. (Also designated grade
“II” according to GOST 3916.1-96.)
There are several more categories of inferior plywood but we are not concerned with them
as they are not suitable for the products we make.
3 mm (3 plies) 13.15Kg
6 mm (5 plies) 19.50Kg
9 mm (7 plies) 25.4Kg
12 mm (9 plies) 32.66Kg
15mm (11 plies) 38.1Kg
18 mm (13 plies) 52.62Kg
21mm (15 plies) 56.25Kg
24mm (17 plies) 59.87Kg
30mm (21 plies) 70.31Kg
38mm (28plies) 83.91Kg
The density has been measured for each size over many samples with the mean value
coming out at around 693.0 kg/m3.
Birch plywood is considered to be relatively homogeneous in terms of the strength
properties, such that even the lowest strength properties are competitive to the strength of
most of the structural softwood alternatives commonly used such as structural lumber C24
or glulam GL 30c. However, these are only ‘strong’ in one direction whilst Baltic Birch
plywood exhibits better ‘strength’ in tension, shear and compression. Moreover, Birch
plywood also exhibits decreased variability compared to the sawn timber in the properties
The hardness of a timber can be measured and Baltic Birch ply compares well to several
other common timbers used in HiFi.
According to the Janka hardness test, the hardness value given for the Baltic Birch is 5600 N.
Black Walnut, North American Walnut 4,500 N, Cherry 4,430 N
These qualities make Baltic Birch Plywood ideal for our uses and it is the tensile strength of
the product which lends itself so well to making speakers. It exhibits properties not
dissimilar to that of a stringed instrument under tension.
Valchromat is a material that we have started to use alongside Baltic Birch Plywood. It is made in Portugal and is actually an evolution of MDF but unlike MDF has several features that are highly desirable in the manufacture of loudspeaker cabinets and furniture.
Unlike ordinary MDF, Valchromat is made up of wood fibres as apposed to dust. These wood fibres are dyed using organic compounds and then bonded together using a special resin which affords Valchromat with its unique features.
These features are:
Colourfast throughout its thickness
High mechanical strength
Lends itself to 3D CNC machining
Low abrasion of tools
Valchromat is available in several colours:
Valchromat is also available in several useful thicknesses all of which we make use of and several different thicknesses.
The density of Valchromat is approximately 800Kg per cubic meter. This gives even small speaker cabinets a pleasing weighty feel.
The Bending strength of Valchromat is 40N/mm sq. This gives us useful and unmatched loadbearing capacity in rack and stand building.
The Modulus of elasticity in bending of Valchromat is 3200N/mm sq. This affords us extremely rigid cabinet work.
Internal bond 0.8N/mm sq.
Once again like Baltic Birch Plywood, Valchromat possesses tensile strength that allows us to make use of it in the cabinet design to enhance the sound of our speakers, much like a stringed instrument.
To read more technical details of Valchromat please follow the links below.