Stranded wire is used in car audio applications due to its advantageous traits: flexibility, durability, and price. However, one disadvantageous trait of stranded wire is the strands. We all know how they can be a hassle when making connections to amplifiers and speaker terminals. If one strand touches another connection or conductive surface, it can short out and cause many issues. When tightening set screw terminals, strands of the wire can be broken or sliced. After set screw terminals are tightened, they push the wires apart from the area of contact. This can cause the wire to fray and is what makes it increasingly difficult to reconnect the stranded wire after it is disconnected so many times. This requires that the wire be cut, shortening the overall length of the wire, and reconnected. This is why many people opt to use wire ferrules.
Wire ferrules are composed of a thin copper tube that is tin-plated. They come in various sizes to fit different gauges of wire. They also come insulated or non-insulated. They are simple to install, you just slide the ferrule over the end of the stranded wire and then heat shrink the ferrule to temporarily secure it. After this is completed, simply install the wire into the amplifier and/or speaker terminals and tighten the set screw to permanently secure it. This application is best for rounded terminals (typically seen on amplifiers). For square terminals, instead of using the set screw to permanently secure it, use a crimping tool. Wire ferrules are not necessary by any means, but they will help you get an overall cleaner installation and ensure an easier removal and reinstallation of stranded wire.
There are many wire ferrule options at Down4SoundShop that can be found here.
Not only are wire ferrules helpful when it comes to wire installs, but so is heat shrink. Heat shrink is a plastic tubing that shrinks when heat is applied to it. In car audio, it is useful for insulating, connecting multiple wires, and color-coding wires. It comes in various sizes to fit different gauges of wire. Sometimes the sizes are listed by gauge, inches, or even millimeters. Below is a chart to make choosing the proper heat shrink size easier. It also comes in many different colors. It is simple to install, for one wire you just slide the heat shrink over the end of the stranded wire and then apply heat to secure it. For multiple wires, you start by twisting the wires together (some people choose to solder them together before adding heat shrink). Next, slide the heat shrink over the end of the stranded wires and then apply heat to secure them.
When used for insulating the wire, heat shrink makes the wire non-conductive and therefore protects against accidental shorts. It also protects against scuffs, scratches, and other low-impact situations. This also protects the wire against liquids, humidity, particles, and in some cases heat. Alternatively, heat shrink can make connecting multiple wires convenient while giving a clean installation. Heat shrink can even be used to color-code wires. making identification of multiple wires a breeze.
There are many heat shrink options available at Down4SoundShop that can be found here.
Here are some installs using ferrules and heat shrink.