A super lightweight carbon fiber spherical-shaped speaker enclosure for live guitar or bass performance:
0.060” wall thickness throughout; so rigid that no internal re-enforcement is required
Suggested 450 watt at 8 ohm Neodimium driver for bass (or) 250 watt at 8” Neodymium driver for guitar depending on enclosure size chosen
Flat response and Ultra-wide dispersion style of enclosure for acoustic instruments
- Acquire a glass salad bowl or plastic bowl-shaped flower pot. Using a permanent marker, divide the internal bowl side surface vertically into 8 equal sections.
- Coat internal bowl/mold surface with a mold release, like a paste wax
- Acquire cross-weave carbon fiber cloth. Cut into trapezoid-shaped pieces, these sized to be a bit more than the height of the side wall times (x) the bowl circumference (top to bottom) divided by 8, plus a little for overlap. The number of pieces will be determined by the thickness of each piece; ie.: use a laminate of 5 carbon fiber cloth pieces if app. 0.010” thickness per piece.
- Acquire a good 2-part epoxy. Mold release a smooth, flat surface. Mix/prepare the epoxy and apply to/saturate one cut carbon fiber piece, do the same to another and lay onto the first. Repeat until the number of pieces (with epoxy taken into account) will equal about 0.060/0.070” in total thickness when the excess epoxy is screeded out. Screed out the excess epoxy when one unit is laid-up.
- Lay this laminate onto on section of the internal bowl surface, insuring that this laminate’s edges go beyond the marker line for that section. Screed to remove excess epoxy and any air bubbles caught on the mold’s surface.
- Repeat this process for all eight sections.
- Allow to fully cure.
- Remove the carbon fiber bowl from the outside bowl mold.
- Trim the new bowl’s top edge, and trim to remove the edge adjoining the bowl’s flat bottom.
- Repeat the process of lay-up for three additional carbon fiber sections.
- Upon completion of this 3 section piece, cut out a disk at or larger than the size of the bowl bottom opening. This will become the speaker enclosure’s grill.
- Based on the size of the ‘open/top’ of the mold bowl, cut sufficient carbon fiber sheets to lay up one carbon fiber panel. Upon completion of this panel, cut out a round section that will be used for the enclosure bottom.
- Layout a pattern that will become the speaker driver grill onto the disk. Using a Dremel or other tool, cut out the grill pattern.
- Glue the grill to the bowl/enclosure’s bottom opening; flush if the same size… or onto the carbon fiber enclosure surface if larger and intended to overlap.
- Mount inset tabs around the back opening to used for the mounting of the back panel.
- Mount the driver to the internal surface of the grill area.
- Install an output jack, and stuff enclosure with an insulation.
- Screw or otherwise attach the back panel and seal.
- The exposed carbon fiber surfaces may require sanding and a surface coating to pretty-up.
- Note: a port or other method may be incorporated to tune the enclosure relative to internal volume and driver specs.
- This project was inspired by what I saw at www.sonuspeaker.com