How to Weatherproof Speakers

By Jeff Grundy

Use simple weatherproofing techniques to convert most indoor speakers for outdoor use.
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When your occasional outdoor activity or party requires music on the patio or in the yard, placing your stereo speakers outside the door or in an open window is simple enough, although a bit inconvenient. If you want to install speakers outside permanently, though, you'll need either to buy expensive units designed for outdoor use or adapt a set of loudspeakers you already own. With some planning and simple weatherproofing techniques, you can protect outdoor speakers from the elements so they'll last for many years.

Protecting Drivers From Water

One of the biggest selling points for outdoor speakers is that they are often water-resistant, or in a few cases, waterproof. Manufacturers of outdoor speakers normally charge a premium for loudspeakers that have drivers treated with special polymers to protect against moisture, rain and snow. However, you can achieve the same result with polyurethane and other brush-on or spray polymers. Many DIY enthusiasts report success in protecting drivers and speaker cones by applying several coats of Thompson's Water Seal or DuraSeal. If you're looking for a polymer protectant designed especially for speakers, you can purchase The Wet Look Pint Clear at your local electronics store or online. Depending on the environment in which you plan to use your outdoor speakers, you may need to reapply the polymer protectant periodically. If you live in a moderate climate, you may need to reapply it once every few years. If you live in a cold, dry or wet area, you may need to reapply the polymer every six months to ensure continuous protection of the drivers.

Protecting the Cabinet

If possible, you should always position your speaker boxes or enclosures in a location that prevents or limits direct exposure to sunlight, rain and snow. The best way to do this is to place them under an eave or large tree. Regardless of where you install your outdoor speakers, though, you should apply a couple of coats of polymer protectant to reduce damage from rain, snow and sunlight – especially if the cabinets are made of wood. Another option for protecting wood speaker enclosures is to apply a few coats of spar varnish. Spar varnish is the type used for finishing and protecting wooden boats. Although a bit more expensive than most polyurethane-based polymers, it does an excellent job of protecting wood from rot and moisture damage and requires far fewer reapplications. If you live in an extremely cold environment, lining the inside of the cabinets with some sort of padding can provide additional protection for crossovers and wiring inside the boxes. If the speakers do not have protective grills or covers for the drivers, purchase some generic ones from your local electronics store and attach them with wood or self-tapping screws to prevent damage from objects blown about by the wind.

Running Cable

If you plan to install your speakers on your patio or porch, simply running the speaker cable under the eave may suffice. However, if you need to place your speakers more than a few feet away from a door or window, you should minimize exposure of the wiring as much as possible. In most cases, this means burying the speaker cable underground. While many companies sell speaker cable billed as "direct-burial" cable, it is usually just regular speaker wiring with a slightly thicker sheath. Most direct-burial cables contain no added insulation or gel to protect wiring from moisture. For long runs of underground cable, using conduit or inexpensive PVC to protect the cables will prevent moisture damage even if you don’t use expensive direct-burial cable. Using conduit or PVC to protect cabling against walls or poles is also a good way to prevent wiring damage. For lengths of wire that you cannot cover or protect with PVC or conduit, wrap with duct tape or another type of weather-resistant tape. Finally, you can prevent moisture damage to the terminals that connect the wiring to the speaker boxes by applying a thick layer of hot glue around the metal contacts and exposed leads of the speaker cables. After the glue dries, it should provide adequate protection for the small area it protects.

Acoustic Concerns

After you convert your indoor loudspeakers for outdoor use, one of the first things you may notice is that they don’t sound as robust or loud as they did when inside your home. Nevertheless, this is normal, as most outdoor speakers lack the bass response and tonal clarity of indoor speakers. The polymer protectant used to protect paper drivers does reduce the effective frequency range of the speakers slightly at the upper and lower spectrums. However, you can minimize bass reduction by placing the speakers so the rear sides of the cabinets face a nearby wall. You can also improve clarity and imaging of your outdoor speakers if you place them within 10 to 20 feet of each other and position their faces so they angle inward slightly at about 15 to 30 degrees. Regardless of where you position your speakers, though, you'll need to increase the volume on your amplifier considerably when listening to music outside, as the sound dissipates much faster outdoors than it does inside your home.