Electroacoustic transducer system
View Patent ↗An electroacoustic transducer system for converting sound waves propagating from a musical instrument drum to an electric signal is generally provided. The system includes a housing, an electroacoustic transducer, and a cover. The housing includes a concave inner surface and a convex outer surface. In addition, the housing defines a housing cavity with a mouth. The electroacoustic transducer is disposed in the housing cavity and faces outwardly from the concave inner surface and towards the mouth to receive sound waves propagating from the drum. The electroacoustic transducer receives and converts the sounds waves in the housing cavity to the electric signal. The cover has a generally planar outer surface and extends over the mouth to at least partially enclose the electroacoustic transducer.
1. An electroacoustic transducer system for converting sound waves propagating from a musical instrument drum having acoustic characteristics to an electric signal for transmission to a peripheral device, the system comprising:
a housing having a rise length B and including a collar having a depth C and diameter D, a concave inner surface and a convex outer surface, the housing defining a housing cavity with a mouth defined by the collar;
an electroacoustic transducer disposed in the housing cavity and having a diaphragm at least partially disposed within the mouth and facing outwardly from the mouth of the housing to receive sound waves propagating from the musical instrument drum, the electroacoustic transducer converting the sounds waves to the electric signal for transmission to the peripheral device; and
a cover having a generally planar outer surface and extending over the mouth of the housing to at least partially enclose the electroacoustic transducer;
wherein the housing rise length B, the collar depth C, and the collar diameter D are selected to facilitate acoustic characteristics of sounds waves received from the drum.
2. The system of claim 1 wherein the convex inner surface of the housing defines a radius of curvature R between 6 and 6.5 inches.
3. The system of claim 1 wherein the diameter D of the collar is about 8.75 inches.
4. The system of claim 1 wherein the length B is 1.75 inches.
5. The system of claim 1 wherein the length C is 0.875 of an inch.
6. The system of claim 1 wherein the diaphragm has a frequency range between 40 hertz and 18 kilohertz.
7. The system of claim 1 wherein the convex outer surface of the housing is partially hemispherically domed and reaching to an apex.
8. The system of claim 1 further including a mounting ring with a diameter less than diameter D of the collar to secure a diaphragm-side of the electroacoustic transducer inside a portion of the housing cavity defined by the collar.
9. The system of claim 1 wherein the housing defines a plurality of vent openings between the concave inner surface and the convex outer surface, the convex outer surface having a longitudinal axis and the vent openings being spaced at generally uniform distances from the longitudinal axis to facilitate air pressure equalization between air inside the housing and air outside the housing.
10. The system of claim 1 wherein the electroacoustic transducer includes an electric circuit having an electric impedance of approximately 250 ohms to enhance quality of the electric signal as the electric signal is transferred from the electroacoustic transducer to the peripheral device.
11. The system of claim 10 wherein the electric circuit filters the electric signal to obtain a desired passband of frequencies between 20 and 200 hertz.
12. The system of claim 10 wherein the electric circuit includes a capacitor having a capacitance of about 220 μF as well as first, second, and third resistors with impedances of about 8 ohms, 22 ohms, and 220 ohms, respectively.