Components and failure points of an speaker cable

There are usually only 3 main parts to any cable. The 2 ends, and the wire in between them. I'll refer to this arrangement as a circuit. Sometimes a number of cables are combined into a
larger collection of cables, called a snake. Snakes are useful because it brings a large group of connectors over to a given area all at once - If you build a snake, always add a few spare circuits to allow for the inevitable dead lines that will appear over time.

A Cable may, or may not have the same types of connectors on both ends. For audio work, these are often 1/4 inch Phone Jacks, XLR connectors and RCA Phono-Jacks. Don't let the names fool you - These were named a long time ago for the function they served then, and the name remains even if you are using it for something different. Some speaker cabinets use unique connectors that limit the type of cable that can be plugged into them - this is good in the sense that you probably won't hook the wrong things up to the wrong cables, but since connector failure is very common, you will need to find sources of these connectors for repair purposes and making spare cables. I often need cables with different connectors on each end to allow me to use devices that happen to have different connectors on them. This can be a royal pain to deal with, but over time, you will probably accumulate a few adapter type cables to allow you to do this.

The connectors and the wire junction points at the connectors is probably responsible for 90% of all SCDS failures. Most frequently, these are where the flex points are and the wire breaks right where it is attached to the connector. From the outside, everything looks just fine, once the connector cover is removed, then you find one or more broken wires. As long as the connector is in good shape, and the connector allows for it, this is repairable. Connectors that are molded together are not repairable - you have to cut the end off and solder in a new connector. People who tug on the wire to pull the connector out of a jack contribute to wire breaks at the connector - Never tug on the wire part of a cable to disconnect it. Get hold of the connector and pull it, not the wire. Stepping on a connector, while it is plugged in, or exerting sideways pull on a cable can cause the riveted parts of a connector to get loose - this is bad, as it now creates a loose connection that will eventually become worse over time. When this happens, cut the damaged connector off and throw it away - replacing it with a new one that is at least as good quality as the one you removed.

The wire inside the cable needs to retain its original design qualities, otherwise, its use will become unpredictable. While 90% of cable failures happen at the junction of the connector and the wire, the rest of the problems often end up somewhere within the wire itself - and in case you didn't notice, you usually can't see into the wire to find the damage. Wire is designed to have a specific electrical resistance and a specific capacitance for a given length of wire. The resistance can change if a wire gets stretched to the point where the wires inside actually start to break. The capacitance can change as the result of heavy things running over or being dropped onto the wire. These problems are amplified when you use sub-standard (junk) cabling. You want the lowest resistance possible as well as the lowest capacitance - you don't want to alter the characteristics of the wire, otherwise, the sound can change. This is far more an issue with low level audio cables (those used for microphones and musical instruments) than cables that are used to drive speaker cabinets, however, if you are paying for quality cables - you want to keep them functional.