Rotary Vane Speakers - new patent

[elektro80]

Eminent Technology’s founder, Bruce Thigpen has invented a new type of loudspeaker, The Thigpen rotary vane transducer.
The transducers sound originates from rotating vanes or surfaces that change pitch in response to the audio input signal. The advantages are small size, improved impedance match with the air, high potential conversion efficiency, low distortion, a very high theoretical limit for acoustic output with a small transducer, and acoustic response to DC.

In a conventional cone type direct radiator loudspeaker, the acoustic impedance match with the air is poor, especially at low frequencies requiring a large surface to achieve high sound levels.

The invention transducer acts against a comparatively large volume of air by dispensing with the cone or vibrating surface of a conventional loudspeaker. Rather than area, in this loudspeaker the impedance match with the air is proportional to the velocity of a vane moving through the air. At diameters equivalent to conventional direct radiator loudspeaker, the invention transducer achieves a superior impedance match with the air creating a low radiation resistance by the motion of the blades. The high velocity vane by its motion sweeps a relative large area and volume of air. The transducer can grab air in close proximity to the blades. The impedance match is proportional to the ratio of the desired output frequency period, the blade rotational period, the number of blades and the size of the blades.
The high conversion efficiency is obtainable because of the high static velocity of the vane can be converted to high particle velocity with a small pitch change. The acoustic output of the device is not limited to motion of air particles in front of a cone or the maximum displacement of the cone. It can move additional air particles pulled into the vane from either side. This method of moving air achieves a much improved impedance match with the air relative to a moving plate of the same area. Horn loading is not necessary with this method of acoustic transduction.
Eminent Technology is currently experimenting with a number of different acoustical, electrical and mechanical methods of altering the pitch or shape of the vane assembly.

A genuine new transducer is rare. This acoustic transducer will not replace conventional speakers any time soon, but test data suggest that it may have a significant advantage in large venue professional speaker applications where high sound pressure level, low or subsonic frequencies are required. Research is continuing to determine optimum configurations and where it can be applied in the market place. A patent application has been filed.



Bruce Thigpen holds seven audio patents, among the Eminent Technology accomplishments are: the first captured air bearing tonearm, the first full range push pull planar magnetic speaker, and the first flat panel computer multimedia speaker. Level 9 Sound Designs, a division of Eastern Asia Technology Ltd., licenses Eminent Technology’s planar magnetic loudspeaker Technology and markets its products under the Monsoon brand name.


http://www.eminent-tech.com/

[mosc]

Another advantage is these could double as fans. This would be an advantage in venues with air conditioning problems.

[elektro80]

Right! They say this speaker design is mostly for soud reinforcement purposes.. add in some smoke and lasers and we have a great show..