Loudspeakers and methods of use thereof

A method comprising:

• (a) selecting a loudspeaker
• (i) an enclosure,
• (ii) a sound panel mechanically connected to the enclosure,
• (iii) a moveable armature mechanically connected to the sound panel comprising a voice coil, wherein the moveable armature is operable for moving the sound panel toward the enclosure along a first axis to create a first air pressure force and away from the enclosure along the first axis to create a second air pressure force, and
• (iv) a magnetic negative spring that has a first magnetic negative spring portion that is mechanically connected to the moveable armature and a second magnetic negative spring portion that is stationary along the first axis relative to the enclosure, wherein
• (A) the magnetic negative spring is operable to provide a first magnetic negative spring force when the sound panel is moving toward the enclosure along the first axis and a second magnetic negative spring force when the sound panel is moving away from the enclosure along the first axis,
• (B) the first magnetic negative spring force is oppositely directed to the first air pressure force,
• (C) the second magnetic negative spring force is oppositely directed to the second air pressure force,
• (D) the first magnetic negative spring portion comprises a first armature magnet, and
• (E) the second magnetic negative spring portion comprises a rotatable magnetic core that is rotatable in the plane that is perpendicular to the first axis such that magnitude of the first magnetic negative spring force and magnitude of the second magnetic negative spring force are varied based upon position of rotation of the rotatable magnetic core;
• (b) rotating the rotatable magnetic core in the plane that is perpendicular to the first axis such that magnitude of the first magnetic negative spring force and magnitude of the second magnetic negative spring force is changed;
• and
• (c) operating the loudspeaker to produce auditory sound.