Cable Types Explained
There are a few types of cables that you'll have to deal with in your studio. So you know what they do, here is a breakdown.
The most common cable is the quarter-inch cable. It's the familiar “guitar cable” that we all know and love. These cables are used for plugging guitars and keyboards to amplifiers, amplifiers to mixers, and mixers to speakers, just to name a few. However, all quarter-inch cables are not created equal. There are specific types for specific uses. The most common is the instrument cable. The instrument cable is used for plugging instruments (guitars, keyboards, samplers) into amplifiers and other sources. The cable carries the mono (one-sided) signal to and from any source you choose.
Instrument cables are also commonly referred to as tip sleeve cables. If you look at the connection end, you'll notice that the tip is separated from the rest of the connector with one plastic spacer. The spacer separates the hot side of the cable that carries the signal from the side that carries the ground.
The other type of quarter-inch cable is the speaker cable. Speaker cables are very different from instrument cables. A guitar or a keyboard puts out a very small amount of power, so you might get some noise, which no one likes to hear in recordings. Instrument cables contain a shield inside the cable to help keep the noise down. But speaker cables push more power through their cables than instruments do. Because of this, they don't need a shield, due to something called signal-to-noise ratio.
Signal-to-noise ratio is
Speaker cables shouldn't be used for instruments and vice versa. The packages clearly state what the cables are used for. When in doubt, ask for help.
Audio cable types
FIGURE 8-1 shows all the connector types: quarter-inch TR, quarter-inch TRS, XLR, MIDI, and RCA.
Tip Ring Sleeve Cables
The tip ring sleeve (TRS) is a quarter-inch stereo cable. Pull out any pair of stereo headphones that you own and look at the plug. Notice how it was two plastic spacers? The quarter-inch tip sleeve (instrument) cable has only one. The extra spacer on the tip ring sleeve is there to accommodate another signal in the cable. Stereo cables carry two separate signals: left and right.
In a studio, a stereo cord is used for two purposes. First, it connects an effect into a mixer or recording device. This type of cable is called an “insert.” Insert cables have the stereo connector on one side and two mono cables on the other side. The stereo line splits the signal so that you can have an input and an output to an effects processor. (If that sounds confusing, don't worry, it's covered in more detail in Chapter 15.) In short, if you're going to use external effects, you'll need to own a few stereo insert cables.
The second use for a stereo quarter-inch cable is for a balanced signal. Balanced cables have the stereo plug on both sides. What does balanced mean? Basically, the cable copies one signal to the two internal wires and performs extra shielding and other electrical magic to cut down the noise.
Balanced cables are used for microphones and whenever cords lengths are very long. This helps cut down on the noise that longer cables usually have.
Balanced cables can be used only if your mixer or recording device supports them. It will be clearly stated in your manual if you can use a balanced signal. You find balanced connections on better recording equipment. Microphone inputs are
XLR is the standard microphone cable, and the letters stand for the three signals carried in the cable. X is for external, which is called the ground, L is for line, and R is for return. The cable is round and has three prongs on one side (the male side) and three sockets on the other (the female side). Microphone cables are always balanced cables. XLR cables are sometimes used for connecting mixers to recording devices, but their most common use is for microphones.
RCA cables, invented by the RCA Corporation, are another type of unbalanced cable. They typically are two mono cables that run together and split off into two ends. RCA cables are commonly used in home stereo equipment.
In the recording studio, RCA cables are used to hook up a tape machine to a mixer and recording interfaces to some computers.
Digital audio signals fall into three categories: The S/PDIF digital cable carries one stereo signal digitally on an RCA cable; the AES/EBU cable carries the same stereo digital signal, this time on XLR cables; fiber optic cables are used for audio. Digital cables can transmit a stereo pair, or in the case of ADAT light pipe, eight signals at once! Digital connectors are very common on recording equipment today — even lower cost ones.
MIDI cables are simple, and there is only one type: five-pin MIDI. You can't possibly buy the wrong one. You'll need one cable for each input, and one cable for each output.