I built the box using 4mm 5 ply Meranti for the sides, 12mm Pine 5 ply for the top and bottom and 2.5mm Finish Birch for the sound board. The wood surface is finished with Danish Oil on the sides and polyurethane on the sound board. All the joints were made with bamboo dowels and secured with cross linking PVA white wood glue.
The Cajon took some tuning and adjusting of soundboard screws, rear port and snare strings before I was happy with the sound.
The Cajon is a true Helmholtz enclosure so the frequency and bass response of the instrument can be tuned. The port diameter and depth was determined using an online port calculator. The cubic dimension of the internal volume of the box was entered into the calculator along with the desired resonant frequency, the port length and diameter are directly proportional to each other. Calculator link
Here is a link to a research paper which I found helpful. link
I painted the motif on to the varnished surface with black enamel paint. I glued a cork tile on top to form a seat.
Here Diane Ponzio and I are engaged in a Cajon duet. Diane plays the cajon very well having a highly developed sense of rhythm from all those years of performing.
