Repair of speaker grills usually involves replacement, as it is difficult to hide patch jobs. Speaker grill replacement is relatively easy, and only requires common hand tools. Replacement grill cloth is easy to source, but finding vintage and discontinued cloth may be difficult. For this reason, and the fact that fabric fading is likely, many folks prefer repairing grills of all speakers so the grills look like stock installations. Methods used to secure the cloth may include staples or glue, but either may be substituted for the other. For the beginner, using staples is the easiest method, and allows grill cloth tension to be adjusted during installation.
Remove the grill frame from the speaker. Most newer speaker grill frames use pins to secure the frame, and are easily pried out with fingers or screwdriver. Some older speakers will use screws to hold frames in place, which may by removed by unscrewing with a screwdriver.
Place the grill frame face down on a flat surface, and inspect to determine the grill cloth mounting method. Even if the existing cloth is secured by glue, staples can still be used, and will facilitate an easier installation.
Remove the grill cloth from the frame by prying up existing staples with a screwdriver, or prying up glued edges with a putty knife. Any logos on the cloth may also be removed, either by unscrewing with a screwdriver, or peeling off glued logos. Avoid cutting or tearing the cloth unless absolutely necessary, as the old cloth will be used as a template to cut the new cloth.
Lay the old grill cloth over the new cloth, and trace the outline with chalk. Make certain that the cloth is lined up evenly along the new cloth's warp and weft pattern (horizontal and vertical weave pattern). Chalk marks are easy to remove, and show up nicely as many grill cloths are dark in colour. If a light colour cloth is chosen, coloured chalk may be used.
Trim the new cloth around the chalk marks with scissors, erring on the side of slightly wider. Excess cloth can trimmed after installation, but cloth cut too small cannot be fixed.
Center the grill frame into position on the new cut cloth. Make sure all frame edges are evenly spaced within the cloth.
Fold one cloth corner over the frame and secure with a staple or two. This will be corner number one.
Pull the cloth firmly but gently to stretch to the adjacent top corner, where it will be folded and secured with staples. This is corner number two.
Staple the edge joining corner numbers one and two. No further cloth stretching should be necessary, and may cause the fabric to "buckle". If retensioning is necessary, Repeat step eight after removing all staples except those in those first corner.
Pull the secured fabric firmly and gently again, stretching it to the third corner, and securing with staples.
Secure the edge connecting the second and third corner with staples.
Stretch the cloth gently to the fourth and final corner, and secure with staples.
Secure the remaining edges with staples, slightly pulling on the fabric with fingers if necessary to maintain tension and straightness of weave pattern.
Trim any excess fabric from the frame with scissors.
Reinstall any logos with screws or hot glue, and install the grill cloth frame onto speakers.
Avoid overstretching of fabric during stapling and tensioning for best results. Follow staple angle patterns (is present) as noted before removing old cloth. Most staple patterns are at a 45 degree angle, to lessen stress while stretching the cloth. If you have vintage or high-priced speakers, always save the old grill cloth. Many collectors favour all original cloth when it's time to sell, even if cloth is damaged.
If grill cloth frames cannot be removed easily, they may be secured from inside of the speaker. Professional advice is warranted at this point to avoid potential speaker cabinet or component damage. Only use grill cloth designed for speakers. The use of other fabrics may not be acoustically transparent, or allow proper air flow, and will greatly reduce the sound and efficiency of speakers. If using an electric staple gun, follow all manufacturer warnings and proper use advice to prevent bodily injury, or harming speaker components.