Concrete Speaker
Personal Project Individual Design 2022
CSS Audio Offers a high-end DIY Speaker Kit Called the Criton 1TD-X. Utilizing their quality audio components, I redesigned the bookshelf unit while keeping the same internal volume.
I wanted to take the opportunity to learn how to work with new materials. I used glass fiber reinforced concrete. This dense material stops the cabinet from vibrating, efficiently transferring all the vibrations from the speaker cones to soundwaves. I used black cherry from the north shore of lake huron, with a tung oil Finish for the front and back faces, and sealed the concrete with a clear coat.
Magnets rest just below the surface of the wood face, allowing for the 3d printed speaker covers to magnetically attach without adding any visual disruptions.
PROCESS
Version 1
The initial design of this speaker was interesting but had some flaws given my limited understanding of concrete at the time.
A complex mold was designed made of melamine and 3d printed components to cast the concrete forms in:
concrete mold Thinckness corrected.pdfGeneral Dimensions:
speaker drawing 1.pdfVersion 1 Failures
Many things were learned about concrete through experience:
Small Details Don't Show Up
Unfortuniatly the concrete stuck to the rough surface of the 3d printed mold, and tore out a large rough chunk instead of embossing the desired pattern. It would have been better to laser-engrave the logo into the wood instead.
Vinyl Sides Sag
The inside of the mold was made coated in vinyl, the weight of the concrete pulled down the vinyl and caused it to sag in the mold, leaving large wrinkles in the surface. It would be better to just use the surface of the melamine molds and sand it smooth afterwards.
3d Prints Eat Concrete
Again, the 3d printed molds for the feet of the concrete did not remove nicly, the layer lines really bit into the surface and it was difficult to get a solid concrete mix into these small areas without air bubble weakening them. Next time i use 3d prints I will sand them well.
Concluding Lessons
Another issue was that it would be difficult to seal this design with the air leaking through the curfing, and it would be difficult to block off the curfing without filling it with glue- which could look bad from the side profile. also the back curfing needed to hinge so filling it with glue was not an option. these issues along with previous ones led to a redesign of the project. I did have success with the internal ribs though and kept those in my final design.
Version 2
One of the challenges I faced was removing the core of the mold without damaging the mold, ultimately I had to cut it out. If I were to do this again I would use vacuum formed parts with lots of draft for the inner molds for easy release. During the molding of the second speaker I rebuilt the core of the mold with cardboard for easy removal. Other then that, I applied lessons learned from the first one and had much more success.
SPEAKER ASSEMBLY.pdf