How to Connect a Speaker Wire to a Phono Plug
By Fred Decker
One of the most universal DIY audio/video projects consists of attaching an RCA connector -- sometimes called a "phono plug" due to its origins on record players -- to a length of wire. In some cases, it's because a piece of audio equipment uses the RCA connection for its speaker output and you can't connect upgraded speakers without it. You can also use speaker wire with RCA connectors as a custom-made patch cord to connect between your audio components. It's the simplest of soldering jobs, and is both inexpensive and useful.
Measure the length of wire you'll need for your specific use. Cut one or more pieces as needed, using your wire cutter/stripper tool.
Place the end of your wire on a cutting board or other work surface and separate the two conductors of the speaker wire by cutting between them with a hobby knife or box cutter. Approximately one inch of separation is usually adequate.
Strip the insulation from your wires, using the stripper portion of your wire stripper. If you're using heat-shrink tubing to cover your finished connector, slide that over the wire.
Unscrew the RCA connector. Slide the outer shell over your speaker wire, along with the strain-relief spring, if it has one. Some higher-quality connectors have a clear tube of insulating plastic inside. Remove it and slide that over your speaker wire as well.
Plug in your soldering iron or ignite it if it's butane-fueled. Place the soldering iron on a heatproof surface near your work area, with the solder nearby.
Heat the end of each wire briefly with your soldering iron, then touch the solder to the heated area. Spread the resulting blob of solder with the iron's tip, so it covers the copper strands and binds them together. This step is called "tinning" the wires. It's optional, but makes it easier to solder the wires to the connector.
Identify the two strands of your speaker wire. One might be copper and the other silver-covered, or one of the strands might be identified by markings or ridges on its insulation. The copper strand, or the one marked with plus signs, goes to the terminal at the center of the RCA connector. The silver-colored strand, or the one marked with a stripe or ridges, goes to the longer outside connector.
Place the end of your positive or copper-colored wire in the small hole of the RCA connector's center terminal. Heat it for a few moments with your soldering iron, then apply a small amount of solder. Repeat, attaching the second wire to the longer outside terminal.
Slide the insulating plastic tube, if you have one, over your soldered connector. Screw the RCA plug back together, threading the outer shell onto the wired portion.
Cover the area where the wire joins the connector with the tube of heat-shrink tubing, if you're using it. Shrink it into place with a heat gun or by rubbing it very lightly and rapidly with the barrel of your soldering iron. This step is optional, but makes a more finished appearance and improves the durability of your cable.
- If you're not comfortable with soldering, a variety of crimp-on and screw-on solderless connectors are available.
- The lowest-priced RCA connectors use a plastic cover. Better plugs are made of stainless steel, and some have a strain-relief spring to reduce the risk of your connection failing over time. The best-quality connectors are made of brass and are gold-plated for corrosion resistance and improved conductivity. With speaker wire, top-quality connections aren't usually necessary. Electronics retailers such as Radio Shack carry a wide variety.
- Most RCA connectors will accommodate 18-gauge wire or smaller. Higher-quality connectors are large enough for 16-gauge wire, but anything heavier won't fit most RCA plugs.
- If you wish, you can cover the entire length of speaker wire with heat-shrink tubing, rather than just the connectors. This gives your wires a more professional appearance.
- Soldering irons can cause serious burns if mishandled. Keep your work area free of children and pets, and use a soldering iron stand if possible to hold your iron while it's heated. Work in a well-ventilated space and avoid inhaling the solder fumes, which are toxic.
Fred Decker is a trained chef and certified food-safety trainer. Decker wrote for the Saint John, New Brunswick Telegraph-Journal, and has been published in Canada's Hospitality and Foodservice magazine. He's held positions selling computers, insurance and mutual funds, and was educated at Memorial University of Newfoundland and the Northern Alberta Institute of Technology.