How to Build an Electrostatic Loudspeaker

1. Spacers are to be cut to the following lengths out of 3/32nd inch (2.38125mm) Plexiglas: Eight, 36.5 inches long by 1 inch wide (92.71cm L x 2.54cm W); Eight, 14.5 inches long by 1 inch wide (36.83cm L x 2.54cm W); Four, 36.5 inches long by 3/8 inch wide (92.71cm L x 0.9525cm W).

2. Spacer edges should be sanded with 100 grain sandpaper to help the adhesive bond.

3. Cover a flat surface with wax paper and lay the pieces out according to plan. Tape the long pieces down with masking tape in their positions. Use IPS WELD-ON # 16 Cement to glue the spacers together. Tape down the rest of the pieces, and use weights if necessary.

4. Make four spacer assemblies using the same procedure.

Glue spacer pieces directly onto the stators  instead of building assemblies.

1. Have the stator panels cut to four panels at 38.5 inches long by 14.5 inches wide (97.79cm L x 36.83cm W) out of 1/16 inch (1.5875mm) perforated metal with 1/8 inch diameter perforations. ( your dimensions may vary.)

2. Clean the packing oil off of the perforated metal with solvent.

3. Straighten out bends or warps in the steel.

4.  Paint the interior of the stator panels with high voltage insulating paint (commonly know as Glyptol™).  I was able to purchase a spray can at a small automotive alternator repair shop.  The panels can then be sprayed on both sides with lacquer. (be sure to mask off electrical contacts first.)

5. Lay a panel out on a flat surface. Mask off the areas not to have contact cement applied with masking tape.

6. Spray contact cement on both the perforated metal and the completed spacer assembly. Remove the masking tape. Wait approximately five minutes, and then lay the spacer assembly over the perforated metal. Add weight to keep the panel flat.  Allow the panels approximately five hours to dry.

Setup Electrical Connections:

1. Cut away a corner of the perforated metal on the rear panel to expose a corner of the front panel for electrical connection. Cut away the Plexiglas on the opposite corner of the rear panel to allow for electrical connections to the rear panel.

2. Sand away Plexiglas on the bottom front panel until the copper foil lays flush. Spray the front of the foil with contact cement and then the area of Plexiglas with contact cement. Attach the copper foil.

1. Lay out the ½ mil mylar film on a clean sheet of cardboard. Cut the sheet to roughly the size of the panels, while leaving approximately a 6 inch margin on all sides. Tape down that sheet with masking tape.

2. Wear latex gloves to keep finger prints from smudging the mylar. Sprinkle some fine graphite powder on the mylar. Take a clean paper towel and rub the graphite into the mylar. Clean off loose graphite with a clean paper towel and a vacuum.

3. Mask off the bottom of the coated mylar with cardboard. Spray contact cement on the unmasked sections. Remove the cardboard mask immediately after spraying the glue.

1. Mask off the metal with the cardboard masks previously used for the diaphragm. Spray contact cement on the exposed Plexiglas spacers.

2. Allow the contact cement approximately five minutes to dry.

1. With the help of another person, pick up the diaphragm and stretch it until it’s tight.

2. Line up the glued section of the diaphragm with the Plexiglas.

3. Lay the sections together and push the mylar onto the Plexiglas.

4. Heat shrink the diaphragm with a heat gun, keep the nozzle about 2 to 3 inches (5.08-7.62cm) from the mylar. Shrink the mylar until all the wrinkles are removed.

5. Using a razor blade, cut away the diaphragm along the edges of the stator panel.

6. Use rubbing alcohol to remove the graphite coating along the area where the diaphragm will contact the spacers on the forward stator panel. Do not remove the coating where the copper foil will contact the diaphragm.

7. Lay the cardboard masks over the diaphragm in-between the spacers. Spray the area not masked with contact cement. Allow approximately five minutes to dry.

8. Lay the cardboard masks over the metal on the front stator assembly, and also mask off the copper foil. Spray the spacers with contact cement.  Allow approximately five minutes to dry.

9. With the help of another person, lay the front stator assembly over the rear stator assembly with the diaphragm. If necessary, lay weights over the completed panel.

1. Cut 2 inch by 1 inch (5.08 x 2.54cm) poplar lumber into four sections 4 foot long (121.92cm), and two sections 14 inches long (35.56cm). Cut a 5/16 inch (7.9375mm) groove 3/8 inch (9.525mm) deep in the center of the long end of the supports. (your dimensions may vary)

2. Push the supports onto the side of the panels. Push the top support on to the speaker panel. Hold the supports together with four 2 inch (5.08cm) drywall screws per side.  

1. Connect the circle connectors to the stator by drilling a 3/32nd inch (2.38125mm) hole. Use a screw, two washers and a nut per connector.

2. Cut the folded copper coil into the shape of a male spade. Tin with solder and connect the diaphragm terminal with a female spade connector.

The Completed Panel: