Specs

Each string enter from one of the rear holes of the top block, exits the front
hole and passes then through the bottom block (the one with two metallic
posts) to finally enter the top block again. The snare string is then secured
with a knot at the exit hole of the top block.
The two blocks are meant to be positioned inside the cajón, the top block
being screwed on with the bolt placed onto the top panel of the cajón, and
secured by the inner wing nut and washer, which have to be tightened all
the way. The upper block is the fixed element in the tuning system that
applies to these snares: the top bolt and wing nuts are not involved in
adjusting the amount of snare tension. That operation can only be made
from the bottom, because those bolts are designed to enter a pass-through
metallic thread placed on the tensioning block. Each bottom block features
a counter-tensioning spring, that prevents the bolt to turn loose.
5
Sound Hole Reinforcement - SHR
Most of our models feature a 3 mm thick back panel: a reduced thickness of
the resonant panel contributes towards a rounded, "fat" bass tone, but it can
become also a structural weak point of the cajón, espicially considering the
fact that the back hole is the only point where the percussionist can pick
the instrument when he wants to move it around. For this reason we apply
a 9 mm /0.35 in square plywood reinforcement right where the hole is going
to be carved, in order to obtain both, solidity and resonance.