System requirements and Installation
Operating system MS Windows 2000, XP and Vista. There is an automatic installer, but AxiDriver can also be installed simply by hand by just copying its files.
What does AxiDriver do?
AxiDriver calculates the sound pressure in front and at the rear of a driver with a cone, dome or piston type rigid diaphragm radiating from an infinite baffle. The baffle can be extended into waveguides of arbitrary shape, as long as it is axis-symmetric. It is also possible to place reflectors in front of the diaphragm.
AxiDriver provides valuable information about the radiation pattern in the near- and far-field. It's great for learning, for understanding what is going on and it's helpful in designing speakers. The program is easy to use and intuitive at entering the data.
The axis-symmetric assumption allows for partial analytical solutions in 3D which is quickening the calculation. Even if the actual problem is asymmetric approximate AxiDriver-models might give insights and clues about the radiation pattern.
AxiDriver displays the near-field at a single frequency as contours, which are overlayed by a sketch of the driver and its diaphragm. Further, the application allows for broad-band analysis into plots of spectra of the sound pressure and radiation impedance with the help of Vacs as a graphing server.
The acoustics is fully coupled to the mechanical rigid body mode of the driver. The layout of AxiDriver is such, that after solving, the motor parameters can be modified and the result is displayed immediately. For example, you can spin up and down the Bl-factor and watch the effect on the response almost in real time.
What does AxiDriver not do?
The diaphragm is rigid, which means that, mechanically, only the axial rigid body mode is taken into account. Higher mechanical modes are ignored. Typically, these so-called break-up modes come in at higher-frequencies and radiate more or less side-ways. The true radiation is caused by the sum of all modes, hence only part of the solution is displayed, although the rigid body mode is usually the most pronounced player.
The model is axis-symmetric, which means we assume a constant pressure along the rings. In reality there would be also radial modes. This is important when comparing the simulation with measurements.
The driver model is linear by assuming a small signal excitation. In reality there can be a significant distortion. Although most of the distortion is typically produced by the motor system, the higher frequency-components, which are generated by this non-linear behavior, add to the radiation at higher frequencies, and through this effect altering the directivity, for example.
Details inside the driver, such as standing waves under the dust-cap and similar effects, are not modeled.