FINESuspension is Non-Linear FEA (Finite Element Analysis) software which is ideal for designing the spider and surround for most loudspeaker drivers.
Starting from a template, the user only needs to input dimensions and select a material from a database to get started.
The deformed surround is displayed in steps up and down.
The calculated stiffness versus displacement K(x) curve is now shown in the upper right window (shown on next page). When the surround is stretched out the stiffness increases, which is displayed as higher K(X) at maximum excursion up (+) and down (-). This curve shape is preferable as the increased stiffness help controlling the loudspeaker cone at extreme excursions up and down.
Ideally the U-shaped Kms curve should be symmetrical along the Y-axis. A non-symmetrical Kms curve will produce a DC offset (X) of the VC position, which would cause intermodulation distortion.
Therefore, the mirrored Kms curve is shown as the dashed curve, making it easy to spot any non-symmetries.
FEA (Finite Element Analysis) Magnetic Analysis and Design Program for Loudspeaker Motors.
FINEMotor is ideal for designing the magnet system and voice coil for all audio drivers. This includes not only woofers and domes but also receivers, headphones, and micro speakers etc.
First input DCR, Cone mass and a magnet size. FINEMotor then calculates all TS parameters and plots SPL with the thinnest wire at left, thickest to the right. The 0.15Ø (nom wire diam.) is a short 3mm Voice Coil winding, which is underhung = shorter than the air gap (4mm). In contrast, the 0.20Ø shows an overhung 6mm winding, which is longer than the air gap and pics up some stray magnet field giving higher SPL.
In FINEMotor you can directly simulate the non-linearity of BL as a function of the VC excursion. This is displayed as the BL(x) curve, which in this case is non-symmetrical left/right (= in/out of the motor). The dashed light blue line is the mirror curve of the BL(x) curve, which makes it easier to see if the BL(x) curve is symmetrical. In that case the two curves would overlap.
The BL(x) curve seen above is not symmetrical, since BL is higher when the VC is inside the motor. This will change in real time as the design of the VC and motor is changed. The green part of the BL(x) curve indicates when BL=82% of the BL at the rest position, so the green curve normally ensures that the distortion is sufficiently low. 70% is useable in many cases and 50% indicates the highest maximum excursion.
Acoustic FEA (Finite Element Analysis) of loudspeaker Cones and domes using lumped element motor part.
The Geometry Modeler (Tools/Geometry Modeler ) makes it much easier to create the geometry for FINECone. From the drop-down menu at left in Figure 2 you simply select the template type, which is closest to the speaker geometry you want to simulate.
The figure shows the Curvilinear Cone Woofer template1, displaying the CAD file (DXF format) at left. You can just change all the dimensions to fit your design in the window at right. You must save your chosen geometry as a DXF file.
The geometry DXF only defines the geometry. The material parameters like thickness, stiffness (E-module) and damping will be defined later.
The software automatically proposes a new project using your new geometry Figure 3. Be sure to press [Yes], as that will setup an entire project model with default materials and ranges etc.
THIS will save you much time getting started with FEM simulations!
In short simulation is a model of a speaker, which shows behaviour / break-up modes and responses of all moving components.
Simulation is used for:
You can do 100’s of simulations and optimizations in one day. Much faster that Trial and Error.