We all know the frustration: Perfectly good, quality stereo speakers either go bad, or get damaged.
And especially those all-to-common sealed speakers that allow absolutely no access, from the front grille, nor the back panel.
Well, in Instructables, we're not cry-babies here, right? We gracefully open those "sealed" stereo speakers anyway -and repair them! Let's keep these perfectly serviceable speakers out of the landfills.
This Instructable will also be useful for those who, simply, resent being "locked out" of their own high-quality equipment and appliances, and desire to open and tinker, anytime, at will.
The tools you'll need:
- Two medium (or large) flat-head screwdrivers.
- One sharp, broad blade wood chisel.
- One phillips-head screwdriver.
Step 1: Access Slots in the Base of the Speaker Cabinet
Lay the speaker cabinet on its back.
Note the two elongated slots, on the base of the speaker cabinet. This is where the two flat-head screwdrivers will need to be inserted at the same time, and gentle pressure applied, to begin the separation of the plastic speaker grille from the wooden speaker cabinet.
Step 2: Applying Gentle Pressure at the Base of the Speaker Grille
Two flat-head screwdrivers are inserted into the elongated slots, at the base of the speaker grille/speaker cabinet, and both screwdrivers are lifted up by the handles, to provide a leveraged downward pressure on the wooden speaker cabinet, and a leveraged upward pressure on the molded plastic speaker grille. This is the only area, on the molded speaker grille, where the flat-head screwdrivers will not leave visible damage, nor damage the brittle wood-composite speaker cabinet.
Easy does it. The typical plastic molded speaker grille will have four, six, or eight tight-fitting peg-in-hole glue points (this particular model had eight glue points). But slow, gentle, but unrelenting, pressure will eventually cause the glue to give way and, one by one, each glue point will loosen up.
If the glued-on molded speaker grille is stubborn, and will not pry apart, don't hesitate to concentrate on one base corner only: One flat-head screwdriver and one broad-face wood chisel carefully inserted along the plastic-wood seam, on the bottom-side of the speaker cabinet. Using firm pressure on the flat-head screwdriver, the corner of the molded speaker grille should lift ever-so slightly, just enough to insert the sharp edge of the wood chisel into the plastic-wood seam.
Be careful not the tear or damage the foam seal that is mashed in this seam (between the plastic and wood), as it needs to remain intact, to prevent vibration on the repaired speaker, as well as form a sound-tight enclosure.
Keep working until the corner peg-in-hole glue point is loosened. Repeat the process on the other corner.
Step 3: Gently Prying Off the Molded Plastic Speaker Grille
With care, but relentless pressure at the seam, work along the side of the speaker cabinet, popping one peg-in-hole glue point after another, until the entire side is loosened.
It may require working only halfway up the seam, and then working up, from the bottom corner of the other side of the speaker cabinet, to eventually coax the molded plastic grille off the wooden speaker cabinet.
Note that the foam gasket is now fully visible at the seam (glued to the wooden cabinet, with this model).
Step 4: Removing Cone Speaker(s) and Gaining Access to the Speaker Cabinet Interior
Once the molded plastic speaker grille is completely loosened, lift it out of the way, but make a special effort to keep the glued areas free of dirt and dust.
In my speaker model, the speaker to the horn was attached to the molded plastic speaker grille and had to be removed (two phillips-head screws).
One cone speaker was then removed, by removing four phillips-head screws, and gently pried off with the sharp, broad-face wood chisel, until it released from a foam gasket-seal. Again, be sure not to damage this foam seal as it prevents vibration, as well as provides a sound-tight seal for the speaker enclosure. The molded plastic speaker grille and speaker cabinet are carefully designed to allow sound to escape in a controlled and restricted manner, to maximize sound. And the foam seals/gaskets ensure this.
Step 5: The Speaker Cabinet Interior, and Reassembly
For most speaker repairs this will be the final step.
The main reason these types of stereo speakers are sealed is because they were never meant to be serviced: Being highly engineered, and with fine-tuned ports and cabinets, any replacement of an internal speaker with a different speaker, even with similar characteristics, will often produce less-than-satisfactory sound. So don't hesitate to refer to some of the Instructables as to how to rebuild (re-foam, re-cone, etc.) your original speaker(s). The internal speakers of many of these units are of high quality, but the cost was kept low, due to the mass-produced quantities. So obtaining a new, OEM internal speaker can sometimes be surprisingly expensive, if not impossible to find.
But in my case, one of the speaker wires had broken off right where it exited the back panel, making a repair otherwise impossible.
The drop of hotglue, holding the speaker wires in place, was removed with the sharp wood chisel, the broken wire spliced, soldered, and shrinktube sealed, and routed back out the back panel and secured with a generous drop of hotglue.
The stereo speaker cabinet was reassembled, in reverse order.
The molded plastic speaker grille was carefully aligned to the peg-in-holes, and pressed back into position, simply using the original, yet still pliable, glue. Using firm pressure, press the speaker grille back in, until all the peg-in-holes are seated and the molded plastic grille is flush at the seam. It may take a few tries before the original, yet still pliable, glue gives way and allows the grille to fully seat.
Also, feel free to completely remove the vibration-absorbing glue, from the peg-in-hole fittings, and simply press the molded plastic speaker grille back into position, as removable stereo grilles function perfectly in this fashion anyway. The original glue seems to be a silicone-based glue, which seemed impervious to the different solvents I tried on it. But a simple peel&rub-off will easily remove the original glue. If, after completion, the finished stereo speaker/cabinet vibrates, or comes loose, during a sound test, it's a quick fix to simply remove molded plastic speaker grille and add fresh glue to the peg-in-hole fittings.
Here are just two of the well-known, removable, vibration-isolation glues on the market, both available in small tubes:
Goop: All-Purpose Household Goop
GE Silicone II Household Glue
Both glues will adhere to plastic, both allow a 6-8 minute working time, 45-60 minute tack free time, and require a 24 hour cure time: Lay the speaker cabinet, face up, on the floor or work bench. Apply the wet and somewhat runny glue directly to the molded plastic speaker grille mounting pegs, and carefully press onto the speaker cabinet until flush and tight. Leave finished speaker cabinet face up for 24 hours, until fully cured, before using speaker.
A Final Note:
If the molded plastic speaker grille was cracked of broken during the process, it can be easily glued back together, good as new.
Just be sure to try a drop of several different types of glues, on the inside surface of the plastic, to see which glue will "melt" the plastic. Allow each drop of test glue to set for about half a minute, to a full minute, and then wipe off with tissue paper. The correct glue will leave a rough shallow "melt" depression. Most of the molded plastic speaker grilles are made of polystyrene plastic, so need a plastic model cement that is formulated to work with polystyrene.
If a crack needs to be repaired: After applying glue, keep the molded plastic speaker grille away from the speakers and speaker cabinet, since the fumes from the drying glue may damage the nearby foam seals/gaskets, causing a less-than-satisfactory repair, and possibly serious damage to those high performance foam-ringed speakers.
Let the glue fully set and cure, for 48 hours, before installing the molded plastic speaker grille onto the wooden speaker enclosure.
mur3633 made it!