File: (Default after start-up)
The first example is already available at start-up. The example demonstrates the simulation of a 250mm diameter cone speaker.
In the sketch the blue lines are parts of the vertical and uniform moving diaphragm. The red lines indicate suspension-rings, which are moving also vertically but here the velocity distribution is such that the velocity is zero at the frame from where it increases linearly. The width of the outer suspension is given by the value of ws2. The other suspension is the spider, which holds the voice-coil in place, and its width is ws0. Black lines indicate reflecting boundaries. The gray lines indicate the infinite baffle. The little dot shows the rotation point for spectral sound pressure analysis.
AxiDriver couples the acoustic field to the motor system through the radiation impedance of the diaphragm. Because in AxiDriver the radiation is independent of the mechanical system (no modes) the motor system parameters can be altered without the need for resolving the acoustic system.
The two plots above display the radiation resistance and reactance. The red curve is produced by the cone and the blue is added for comparison with the radiation impedance of an equivalent disk. The cone-cavity emphasizes the radiation in the proximity of 1kHz. In contrary to flat or convex shaped diaphragms, which exhibits only mass-like reactance curves, has the cone also a frequency range with stiffness-like properties, as can be seen by the negative reactance in the range 1k...2kHz.
AxiDriver lets you also calculate the motion of the voice-coil and the electrical driving point impedance.
There we run into a small problem, which effect is that the fundamental resonance might not be visible in the resulting curves. The cause is the coarse frequency-resolution in the lower frequency band. If we want to investigate the fundamental resonance then the only way is to change the frequency range on page Solver, say fmin = 10Hz, fmax = 200Hz and Num frequ = 50, and then to re-solve the total system. The result should look like the following graph: