Improvements in the construction of resonance boxes (Machine-translation by Google Translate, not legally binding)

摘要

Improvements in the construction of sound boxes, characterized by the arrangement of an acoustic filter in which previously have been established a series of grooves arranged symmetrically, whose filter consisting of a thin wooden board is placed in the box of the soundboard between the upper part where the loudspeaker goes and the resonance box itself or lower part, all of them well conditioned with an absorbent material that allows high fidelity in the reproduction of the sounds captured by the receiving apparatus. (Machine-translation by Google Translate, not legally binding)