This simulator sections a moving-coil loudspeaker driver to show the cone and dust cap, voice coil in the magnet gap, magnet and pole structure, surround and spider, and basket. Change drive frequency, peak current, force factor Bl, moving mass, suspension stiffness and damping to see force, cone displacement, velocity and the free resonance.
• A sectioned 3D moving-coil driver with the cone and dust cap, the voice coil sitting in the magnetic gap, the magnet and pole structure, the surround and spider suspension, and the basket and mounting flange. • Controls for drive frequency, peak current, force factor, moving mass, suspension stiffness and mechanical damping. • Six readouts: free mechanical resonance, instantaneous force, cone displacement, displacement amplitude, cone velocity and mean mechanical dissipation. • Curves & measurements, two guided experiments with a verification bench, and Learn & assess lessons and a quiz.
The voice coil in a magnetic gap produces force F = Bl·I. That force drives a lumped mass M on a suspension of stiffness K with mechanical damping R. The free resonance is ω0 = √(K/M), and the steady displacement amplitude is X = Bl·Ipeak / √[(K − Mω²)² + (Rω)²] with phase atan2(Rω, K − Mω²).
Below resonance motion is governed mostly by stiffness, near resonance by damping, and above resonance by mass. Doubling the moving mass lowers the resonant frequency, and less damping makes the peak near resonance taller.
The driver is an ideal current drive with a lumped mass, stiffness and damping. There is no electrical back-EMF solution, enclosure, cone breakup, SPL prediction or excursion limit. Geometry motion is enlarged 40 times and visual time slowed 100 times. It illustrates the mechanical behavior of a driver's moving parts rather than predicting its acoustic output.
Current in the voice coil sits in a radial magnetic field, producing force F = Bl·I, where Bl is the force factor in newtons per ampere. The simulator lets you change Bl and the peak current.
The free mechanical resonance is f0 = (1/2π)√(K/M), set by the suspension stiffness and moving mass. Doubling the mass lowers it, as the second experiment demonstrates.
Mechanical damping removes energy each cycle. With smaller R, the displacement peak near the resonant frequency grows taller, which the Low damping experiment shows.
No. It models cone displacement and velocity from an ideal current drive, without enclosure effects, back-EMF, cone breakup or SPL calculation.