Lets begin with the material. High quality musical instuments can only be made of high quality wood. The wood must be flawless: free from visible defects (free from color variations, knots, burls, swirls and streaks ) and free from its corrections. The plywood must be obtained from proper storing conditions (horizontally laid on even surface, optimal humidity and temperature). Top quality plywood are labeled as grade A or B. The type of wood used most frequently for cajon – similar to the drum shells – is the birch plywood. It is a very strong and resistant material and gives a very good vibration when used for percussion instruments. I also make cajons from birch plywood. There are, of course, cajons made from other types of plywood (eg maple, or beech, which is mainly used for playing surface) and also there are cajons made of solid wood.
The cajon body size is also important. I can say I’m working with a ‘standard’ size (Height 49 cm x Width 29 cm x Depth 30 cm), which used by most cajon manufacturers. The body (the base, the top and the two side) is 10 mm thick, the back is 6 mm thick, and the front (playing surface or tapa) is 2.5-3 mm thick plywood. The 12 cm diameter circular reflex hole is located at the back of the instrument, at its upper third. All of these parameters have evolved over the years, and are well-proven for cajons.
The cajon body is assembled only by gluing and clamping, without nails and screws. Why is it done so? For proper vibration. For fixing the playing surface, however, we can use screws that are attached to a reinforcing frame embedded in the body. Size, exact location
and tightness of the screws also determine the tone & sound of the cajon. Is the cajon equipped with string(s) or with snare wire(s)? Where are exactly the string(s) or wire(s) within the instrument? How these strings or wires are set? These things also largely
determine the sound.
By the way… if the manufacturer devotes time to adjust and test the finished instruments before they get to the Customer, needless to say, the instrument will sound much better.
Would you have thought that storing the finished instruments properly could affect the sound? It is recommended to store musical instruments at near-constant humidity and temperature, free of direct sunlight (UV radiation).
Your playing technique
And the last thought I would mention would be the individual playing technique and playing style which largely influences how a cajon sounds. It is not the same how and where the cajon is hit… But this will be discussed in details in another blog post.
Until then „keep calm and play the cajon”
Greg Teglas, the manufacturer