Most loudspeakers are really hard-pressed to deliver low frequencies down to 40 cycles per second (or Hertz - named after Physicist Heinrich Hertz who studied electrical oscillations) or so. Some can go down to 20Hz but below that is inaccessible. Until now.
Meet Bruce Thigpen and his Rotary Woofer:
Want to hear what 5Hz sounds like? A new woofer technology unlike any other and a new product category for home audio. This is the first home audio woofer delivering true response to DC. The Thigpen Rotary Woofer is the worlds first true infrasonic home audio or home theater woofer. Conventional subwoofers roll off rapidly below 20Hz. With no cone the rotary woofer achieves high efficiency at very low frequencies. Most subwoofers have a difficult time producing acoustic output below 20Hz at audible levels. They generally require large amounts of equalization, distortion rises rapidly, and even the most expensive available cannot produce significant output below 10Hz. Subwoofer electronics usually contain a cutoff filter which sharply rolls off content to the subwoofer below 20Hz to protect the speaker. On the other hand, the rotary woofer has enough acoustic output to move an open door back and forth 0.5" between 1 and 5Hz! It has enough output to find resonance frequencies of walls and ceilings in a room. It requires no equalization to achieve flat response to below 1Hz. Microphones have low frequency capability that far exceeds the low frequency output of current subwoofers. In many cases infrasonic information is in a recording, it is not being reproduced by the sound system.
A missing link in sound reproduction. Experience special effects like never before. If you want to hear and feel the 11hz hertz fundamental frequency from a helicopter rotor, the low frequency rumble of wind, the space of a concert hall or infrasonic information contained in an explosion, this is the only woofer technology available. Over the years the generally accepted low frequency limit of hearing has been 20Hz, some suggesting 16Hz. However nothing existed to produce significant enough output to change this belief. This development will spawn new special effects and we will begin to understand the true low frequency limit of human hearing. The TRW-17 rotary woofer is now being used in theme park attractions, concert venues, professional audio applications and research projects.
PFM - all it is is a ducted rotary fan. The pitch of the blades is varied by the incoming audio so this provides high fidelity bass response from 20Hz down to Direct Current.
Their market is theme parks, museums, music and scientific research.
I understand that the market is a small one and they are a corporation that spends a lot on research and development. I would still love to have one here at the farm - price of entry is a bit too steep for my blood. $13K for the transducer itself and another $3K for ancillary bits and bobs. Very clever idea.
Leave a comment