Patent ID: 7754951

Claim:
A string musical instrument comprising: strings to produce sound, where the energy of the vibrating strings is transmitted into the instrument body by means of a string bridge, a primary sound box, or chamber, further comprising an outer back with a continuous vent along the rim and a projection flange, an inner back forward of the outer back, a sound board at the front having a string bridge, all of which form the primary sound box, or chamber, and an angled side wall angling inward from the front interconnecting the edges of the soundboard and the inner back wherein said sound box forms a first resonance cavity between the said sound board and the said inner back and the said angled side walls, the inner back has sound holes to communicate sound into a second sound chamber that is formed between the said inner back and the said outer back, an outer back with an outward facing continuous vent along a perimeter rim of the outer back release sound from the said second sound chamber and the projection flange projects the sound forward along the angling side walls; the soundboard vibrates and excites the air inside the said first cavity causing sound, the sound is then communicated out the said holes in the said inner back, which is then forced to the continuous vent at the outer rim of the said second sound chamber and is projected forward from the outer back by the said projection flange.