Wireless audio technology is constantly improving, but we still need cables to connect devices in audio systems. These, in turn, are divided into 2 classes—balanced and unbalanced. They are often called by the type of connectors installed by manufacturers. In general, for unbalanced cables, it will be RCA, and for balanced, it will be XLR. We will consider the difference between them below.
Unbalanced Audio Cables
Any electrical cable acts as an antenna and is excellent at picking up various electrical interference. The longer the antenna (cable), the more effective it is. In a modern house or apartment, electrical interference is widespread! All of it affects the cable and the signal transmitted through it. TV and radio broadcasts, Wi-Fi, Bluetooth, cell phones—all these and many other home devices emit and receive signals we need, but not the audio cable. Their presence in the signal is absolutely undesirable.
Unbalanced cables can only rely on their own shielding for protection against external interference. It is hidden under the outer jacket and can be a braid of very thin wire, foil, or even multi-layer. The shield surrounds the signal conductor from all sides and takes on interference, preventing it from getting into the transmitted signal. However, the shield cannot provide absolute protection, and some interference will still be in the signal.
Unbalanced cables can have a different design, but the essence of it will always be the same. In them, one conductor is used to transmit the signal, and the other is used as a “common wire” or “ground.”
Balanced Audio Cables
If an unbalanced cable has one signal conductor, a balanced cable has two. One carries the standard signal and is called the “positive” conductor. The other conductor in a balanced cable carries the same signal but is inverted in phase. This is the “negative” conductor. A balanced cable has a third conductor, the “common” conductor, which is the basis for the three-pin design of XLR connectors. The term “half-balanced” for an unbalanced cable means that although it has two conductors (except for the shield), only one is the signal conductor.
After arriving at the receiver, the inverted negative signal is inverted again and is in phase with the positive signal. Both signals are summed, and the amplitude of the resulting summed signal increases. However, electrical noise is induced on both conductors in the same phase, and when the phase of the inverted signal is reversed, the noise is also inverted. As a result, when the two signals are added together, their interference cancels each other out.
Three pins in the XLR connector sometimes mislead novice music lovers, who may think it is used for two channels. In fact, this is not the case. A stereophonic device with balanced connection capability will have separate XLR connectors for each channel. This site offers a variety of XLR cables.
As a result, a balanced connection is much better protected from interference than an unbalanced connection, however, on one condition. It is essential that both the signal source and the receiver also have actual balanced circuits.
A Bit Of Theory
The purpose of any cable in an audio system is to carry the signal from the source to the receiver without any modification. In other words, the cable should not affect the transmitted signal. This would be the case in an ideal world, but this is not the case.
The degree of this influence will depend on many factors. First and foremost are the materials from which the connector is made. The cable uses metal as a conductor and dielectric as an insulator. Their choice will directly affect the cable’s electrical characteristics and, therefore, how the connector will affect the transmitted signal.
