| US 7,485,791 B2 | ||
| Golden ratio air vent holes | ||
| Akito Takegawa, Chiba (Japan) | ||
| Assigned to Pearl Musical Instrument Co., Chiba (Japan) | ||
| Filed on Apr. 17, 2007, as Appl. No. 11/736,204. | ||
| Claims priority of provisional application 60/880005, filed on Jan. 12, 2007. | ||
| Prior Publication US 2008/0168887 A1, Jul. 17, 2008 | ||
| Int. Cl. G10D 13/08 (2006.01) | ||
| U.S. Cl. 84—411R | 12 Claims |
| 1. A drum comprising:
a hollow drum shell having first and second opposite ends;
at least one opening through said drum shell for acoustic venting,
wherein said at least one opening is located at a position distanced from at least one of said opposite end by a preset distance
within a predetermined deviation,
wherein said present distance is calculated by dividing a total depth of the drum shell by 2.618.
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