Full Frequency FEA Study
Setup
A free-free boundary condition was used to isolate the enclosure’s own panel dynamics without adding artificial constraints. Remote Mass features were applied at the driver mounting locations to represent the 1.5kg woofer and 0.59kg tweeter. Generic MDF material properties were used for all panels, with an elastic modulus of 3000 N/mm², a Poisson’s ratio of 0.3, and a density of 750 kg/m³. This setup provided a consistent baseline for comparing different bracing configurations.
Three Bracing Configurations
Mode Frequency Comparison
Findings
Heavy bracing’s fundamental mode landed only around 70Hz higher than the no-bracing fundamental, but the character of the modes changed in a useful way. Many of the modes following the fundamental in the heavy-bracing configuration were dominated by the brace panels resonating rather than the enclosure panels themselves. The heavy-bracing modes also showed less panel coverage overall, often concentrated over smaller surface areas of the panels compared to the no-bracing and light-bracing configurations. The main goals were to push up the fundamental frequency and reduce the severity of other audible modes, and the heavy bracing scheme accomplished both. With more material and internal space, the bracing could have been extended to connect to all four enclosure panels, which would likely push resonant frequencies even higher, but that was not feasible within the project’s space and cost constraints.
No Bracing
Light Bracing
Heavy Bracing