While the theory of planar magnetic transducers is conceptually relatively simple and has been known for several decades, planar magnetic transducers have found only limited acceptance and use in speakers, mainly due to difficulties associated with limited diaphragm excursion and magnetic field strength.
Due to the above difficulties and other disadvantages, currently known speakers with planar magnetic transducers typically exhibit relatively low sound pressure levels (SPL) and often significant distortion at higher SPL. While the excursion range of the diaphragm can be increased by increasing the distance between the magnets and the diaphragm, such increase is typically only achieved at the expense of loss in strength of the magnetic field. To remedy such problems, a second opposing row of magnets may be implemented to form a push-pull system. Unfortunately, the increase in SPL using such known system is relatively limited. Still further, and especially where multiple transducers are employed, inhomogeneities in physical diaphragm parameters will substantially affect accurate sound reproduction. Thus, currently known planar magnetic speakers are typically employed in the high-frequency range (e.g., as tweeters) and/or in speakers in which high sound pressure levels are not desired.
Therefore, while numerous speakers with planar magnetic transducers are known in the art, all or almost all of them suffer from one or more disadvantages. Consequently, there is still a need to provide improved devices and methods for planar magnetic transducers.