Driving a multitude of small diaphragms with motors instead of speaker coils promises big bass-audio response in small volumes. Supported by three papers, Tymphany Corp. demonstrated this concept at the Audio Engineering Society (AES) conference in San Francisco last month.
The company's Linear Array Transducer (LAT) technology is based on multi-diaphragm loudspeaker transducers in a tubular form factor. The transducers consist of a conventional motor structure, a tubular housing, and multiple diaphragms.
Opposing end motors drive the coupled diaphragms. One motor drives half of the diaphragms, while the other motor drives the other half in opposition. Sound radiates through multiple flow ports along the side of the housing. The transducer can be mounted horizontally or vertically.
LAT speakers deliver more bass in a third of the transducer space of comparable cone transducers. They also fit into rectangular spaces more efficiently. The balanced drive design cancels out harmonic distortion, resulting in lower distortion than conventional transducers. The opposing end motors cancel out structural vibration.
LATs scale from 5 to 30 cm (2 to 12 in.) in diameter, at any length, and are stackable for higher sound power. They're lighter than traditional transducers with comparable output. And, they're compatible with vented-box, transmission-line, infinite-baffle, and sealed enclosures.
Bass response is the bottom line for LAT technology. Tymphany describes 100-W (continuous) extended-range woofers with 40- to 4000-Hz response, 150-W subwoofers with response from 25 to 600 Hz, and 600-W megawoofers with 16- to 300-Hz response. The extended-range woofer would measure 6.4 cm (2.5 in.) in diameter by 15.2 cm (6 in.) long. The subwoofer would be 8.9 cm (3.5 in.) by 38.2 cm (15 in.), and the megawoofer 15.2 (6 in.) by 61 cm (24 in.).