With a balanced cable, two wires transmit signal in opposite directions so that the noise on one wire will be opposed by an equal-but-opposite signal on the other wire.
The result is a stronger signal with less noise, which means it’s better for long cable runs where there are more chances of picking up interference from external sources such as fluorescent lights or motors.
Balanced cables also offer protection against ground loops – when one device sends out a voltage spike and another picks it up through its grounding system – because each line has three possible paths for current flow: both legs, or only one leg but not the other.
Unbalanced cables, on the other hand, use a single wire to transmit both positive and negative signals. They are generally less susceptible to interference than balanced cables in short runs, but if noise is much higher on one of them (due to electromagnetic interference or impedance differences), then there’s no way for the signal that’s weaker by comparison to overpower it.
The two signals will cancel each other out, so the stronger will prevail, with negative results for your audio quality. That’s why unbalanced cables are not recommended for professional installations.
In this article we will cover:
- What is the difference between balanced vs unbalanced cables
- Advantages of using balanced vs unbalanced cables
- Disadvantages of using balanced vs unbalanced cables
What is the difference between balanced vs unbalanced cables?
This article explains the differences of using balanced and unbalanced audio (in this case we will focus on digital audio). The terms ‘Balanced’ and ‘UnBalanced’ are often used in reference to cabling for electronic devices such as microphones, analog-to-digital converters, professional video cameras and other such devices.
Advantages of using balanced vs unbalanced cables
Longer Distances: As you know, the longer the cable the greater is the resistance that is introduced due to interference by EMI fields in air. If a signal path is run balanced where there are two conductive paths in paired shielded lines, the crosstalk interference between them is equal in magnitude but opposite in polarity. This results in the noise being cancelled out by the receiving end of the cable. The noise will not be present at all if both wires have identical impedance and length (this does not apply to cables > 25 feet).
Disadvantages of using balanced vs unbalanced cables
Higher Cost: The equipment requires at least one more balanced/unbalanced converter to change from an Unbalnaced to a Balanced transmission. This cost is higher for systems that have different numbers of channels being used (e.g. the number of microphones and or instruments connected). Another disadvantage to this method is that the system must have a balanced interface, which means that each channel requires a conversion from either Balanced to Unbalanced or vice versa.
What are some plugs for the different cable types?
TRS and XLR are typical balanced-connector cables in audio systems, while TS, RCA, SpeakON, and banana plugs are commonly used for unbalanced-connector cables.
“TRS” stands for “Tip, Ring, Sleeve.” It looks like a regular sized plug, but has an extra ring attached to the shaft. Two conductors are included in TRS cables, plus a shield (ground). Often, they are used for right and left mono output into headphones with stereo or even into balanced equipment. The stem of Y cables is also fitted with TRS connectors. Signals are sent through one wire and returned through another in mixer insert jacks.
The XLR connector has three pins: ground, negative, and positive. Transmission of balanced microphone or line-level signals is usually carried out via these systems. XLR cables are commonly used in audio to connect microphones to mixers and power speakers to various outputs.
A TS connector is an unbalanced, 2-conductor connector with a tip and sleeve design. The insulator is a non-conductive ring that is inserted in the middle of the tip and sleeve to prevent contact. The tip of the signal is considered the “hot” or “carrier.” The sleeve connects the ground to the insulator which cleans up any excess noise, which is great for guitars and other instruments.
Consumer stereo equipment uses phono connectors, commonly known as RCA connectors. Connectors of the RCA type are typically found on inputs and outputs of tape players and CD players. In most cases, however, true S/PDIF cables are higher quality and stronger than RCA connectors for digital audio connections.
Connecting a power amplifier to a PA speaker or stage monitor requires a speakON connector. A lockable connection like this is often preferred over a 1/4″ TS connection. Additionally, they avoid risky cabling mix-ups because you should never connect an amplifier and speaker with any instrument cable.
Banana plugs are typically used to connect audio cables. Many power amplifiers use banana jacks or binding posts on the back. This jack is usually located at the end of the binding post on the back of power amplifiers. These wire ends are secured using a locking screw.
Winding Up (That’s a Cable Pun)
The signal path in an XLR connection is balanced; note how both wires carry a positive signal but one goes to pin 2 and the other 3.
Pictured from left to right: single-ended (unbalanced) RCA jack, balanced XLR connector, unbalanced TS male phone plug. The TS is the most common type of unbalanced connection found on consumer audio gear.
So why do so many consumer devices rely on an unbalanced connection? Mainly because they’re less expensive, easier to manufacture and because the cables are more compact. That’s why you’ll find single-ended RCA jacks on home stereos and powered speakers, along with unbalanced TS male phone plugs. Also, some sources (e.g., turntables) can send out an unbalanced signal that requires an unbalanced connection.
If you only have a single RCA cable, use it to hook up the left and right channels of the same device into your amp or receiver. If all three are present, connect the center channel – which carries mono sound as well as any other data intended for both speakers such as speaker-calibrating information – to the corresponding pin on your amp or receiver.
Connecting the center channel is optional: you can hook up both speakers to the left and right channels if you don’t need a mono signal, but doing so will reduce any available surround sound options that require two channels (e.g., Dolby Pro Logic IIz) by half.
Just remember that the above applies to unbalanced connections, while XLR cables, which have a balanced three-wire design, should always be used when connecting components with balanced outputs (e.g., microphones and preamps)
In conclusion, In reality there is no real advantage of using one wire over another for normal everyday use so long as they are both good quality and shielded if used in an audio setting.