Audio signals are an essential part of our daily lives, whether we are listening to music, watching movies, or making phone calls. There are different types of audio signals, and they can be transmitted in different ways, including balanced and unbalanced signals. These terms are commonly used in professional audio applications, such as in recording studios and live sound systems, but they can also be useful for home audio systems and other applications.
In the context of audio or electrical signals, a “balanced” signal refers to a type of signal that is transmitted over two wires or conductors, which carry equal and opposite voltage signals with respect to ground. The two signals are said to be “out of phase” with each other, meaning that one signal is positive while the other is negative, and the net voltage across the two wires is therefore zero. This is in contrast to an “unbalanced” signal, which is typically transmitted over a single wire or conductor with respect to a ground reference.
The main advantage of a balanced signal is that it is less susceptible to noise and interference than an unbalanced signal. This is because any external interference that affects the two signal wires will affect them equally, and the balanced receiver can detect and reject this common-mode noise by subtracting the two signals. In contrast, an unbalanced signal is more vulnerable to noise and interference because it has only one wire to carry the signal, which is more susceptible to interference from external sources.
Balanced signals are commonly used in professional audio applications, such as in recording studios and live sound systems, because they provide a high level of noise immunity and can transmit audio signals over long distances without degradation.
Balanced/Unbalanced do not necessarily mean Stereo/Mono
Balanced vs unbalanced signals and mono vs stereo signals are two different concepts that are sometimes confused with each other, but they are not the same thing.
Balanced and unbalanced signals refer to the way a signal is transmitted over wires or conductors, and whether there are one or two signals being transmitted. A balanced signal is typically transmitted over two wires or conductors, which carry equal and opposite voltages with respect to ground, while an unbalanced signal is typically transmitted over a single wire or conductor with respect to ground.
On the other hand, mono and stereo signals refer to the number of audio channels being transmitted. A mono signal is a single audio channel that is transmitted over a single wire or conductor, while a stereo signal is typically two audio channels that are transmitted over two wires or conductors. In a stereo signal, the left and right channels are usually balanced, meaning that they are transmitted with equal and opposite voltages, but this is not always the case.
It’s important to note that it’s possible to have a balanced or unbalanced signal that is either mono or stereo. For example, a balanced stereo signal might be transmitted over four wires (two wires per channel), while an unbalanced mono signal might be transmitted over a single wire with respect to ground.
In summary, balanced vs unbalanced signals and mono vs stereo signals are two separate concepts that refer to different aspects of audio signal transmission. While they are sometimes confused with each other, it’s important to understand the difference between them to properly setup and connect audio equipment.
Example of Balanced cables:
- XLR cable : XLR cables are commonly used in professional audio applications and are a type of balanced cable. They typically have three pins or connectors, which carry the positive, negative, and ground signals. XLR cables are designed to minimize noise and interference by transmitting equal and opposite voltages on the positive and negative pins, which cancel out external noise that might affect the signal.
Please note that although most of the time XLR cables are balanced cables, they can also come in unbalanced option (usually come in pairs). - TRS cable : TRS cables are also a type of balanced cable and are commonly used in audio applications, including headphones, and studio monitors. They have three contacts, typically used for left audio, right audio, and ground.
Example of Unbalanced cables:
- * RCA cable : RCA cables are commonly used in home audio systems and are a type of unbalanced cable. They typically have two connectors, one for the signal and one for ground, and are used to connect audio components like CD players, turntables, and amplifiers.
- 1/4″ instrument cable (TS cable) : Instrument cables are commonly used to connect electric guitars and basses to amplifiers and are typically unbalanced cables. They have a single connector on each end and carry the signal and ground on the same wire.
So, it’s important to understand the difference between balanced and unbalanced signals, as well as their advantages and disadvantages, in order to make informed decisions when setting up and connecting audio equipment using different cables from different sources to different destinations.
Mistaking balanced and unbalanced signals can lead to noise and interference, signal loss and distortion, equipment damage, and incompatibility between your audio equipment.