2010 | Student Work | Western Washington University
Rotomolding…. FTW?
The speaker enclosure was a three week long student team project. It was designed specifically for the rotomolding process. My responsibilities included providing background information on speaker enclosure design, sketching, some 3D modeling, and the final renderings.
An ideal speaker enclosure is non-resonant, has few parallel walls, and has the correct volume for the speaker driver installed. This directed the shape we chose, which is primarily spherical, eliminating the distortions potentially created within a rectilinear enclosure.
The part is rotomolded as a single piece, which is then cut into two, the inner and outer housing. Holes are drilled for the fill point at the bottom of the outer enclosure, as well as at the back for installation of the binding posts to connect the speaker wire. The inner housing has holes drilled for the mounting points of the speaker.
One of the easiest methods for dampening resonance in housing material is adding mass. This design has two chambers, creating a double-walled enclosure. The speaker driver is installed, and shipped to the end user, who customizes their enclosure by adding a material of their choice. Sand, or even concrete could be used to fill the enclosure. Housing color could be opaque, or possibly transparent to showcase the dampening material. Keeping the product light weight until it reaches the end user saves shipping costs, reduces fuel consumption, and allows the user to utilize local materials.
This view shows the speaker driver, and inner and outer enclosure pieces.
A small diameter full range driver was selected for this enclosure. The listed specifications served as the basis for the enclosure volume calculation.
