ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01
1pEA7. Neodymium iron boron and professional audio loudspeakers.
Daniel M. Warren
Peavey Electronics Corp., 711 A St., Meridian, MS 39302
Neodymium iron boron, a high reminence, high coercivity permanent magnet
material, has been in use in the audio industry for several years in the form of
small (approximately 1-cm-diam) disks in high-performance microphones. Dropping
prices and continuing enhancements in material properties, reducing thermal
demagnetization and increasing residual magnetic flux density, have made
neodymium more attractive for use in professional audio loudspeakers, where
magnent size can reach 4 in. in diameter and almost in. thick. While
still considerably more expensive than the more commonly used ferrite ceramic
magnets, neodymium magnet structures can be smaller and have a higher flux
density than can be practically attined with ceramics. A specific example of
loudspeaker motor structure design using neodymium---the Architectural Acoustics
Neo Series Acoustical Components from Peavey Electronics---will be presented.
Acoustical implications of high-force loudspeakers on enclosure design will also
be discussed. [Work supported by Peavey Electronics Corporation.]