If you use musical instruments and audio equipment regularly, you’ve probably come across cables and connections labelled balanced or unbalanced. But if you’re fairly new to it, or you’re not too interested in the technical side of things, the difference between them might not be completely clear. When you’re plugging into your gear, though, it’s good to know exactly what you need and why.
Many balanced and unbalanced cables use connectors that fit into the same sockets, so it’s easy to assume it doesn’t really matter which one you use. But in some situations, it can make a noticeable difference.
In this guide, we’ll look at balanced vs. unbalanced cables. We’ll walk you through how to tell them apart and when to use each type.
Key takeaways
- Balanced cables have three wires inside; unbalanced have two
- Balanced cables are better at keeping noise out, especially over longer runs
- Unbalanced cables are simple and totally fine for short distances, like guitars
- Some connectors can look the same, especially TRS jacks, but don’t always do the same job
- If one part of your setup is unbalanced, the whole signal becomes unbalanced
- DI boxes help clean things up by turning an unbalanced signal into a balanced one
Balanced vs. unbalanced cables
Overview
When you plug your audio cables into your equipment, the cable and the connector on the device will be either balanced or unbalanced. The difference between them physically is quite simple.
An unbalanced cable has two points of contact on its jacks and ports, along with two conductor wires inside the cable. These are split into a signal wire and a ground wire. The signal wire carries the audio, while the ground helps reduce interference from the devices the cable is connected to, but it doesn’t do much to stop noise picked up along the length of the cable.
A balanced cable, on the other hand, has an extra point of contact on its connectors, as well as an extra conductor wire inside the cable itself. This means it carries two signal wires along with a ground.
The two signal wires are individually shielded, while the ground acts as an overall shield. One signal is sent normally, and the other is sent with its phase inverted.
At the other end, the inverted signal is flipped back to match the original. This allows any noise picked up along the cable to cancel out, while keeping the original audio signal intact. This is called phase cancellation.
Phase inversion and noise cancellation
Phase cancellation might sound technical, but the idea is quite straightforward.
In a balanced cable, the audio signal is sent down two signal wires. One carries the normal signal, and the other carries the same signal but with its phase inverted.
As the signal travels, both wires pick up the same interference from things like power cables or lighting.
When the signal reaches the input, the inverted signal is flipped back. This also flips the noise, causing it to cancel itself out when the signals are combined.
The result is a cleaner signal, which is why balanced cables are useful for longer runs or more complex setups.
Balanced cables
Balanced cables are designed to reduce noise, which makes them better for longer runs and professional setups.
They use three conductor wires. Two carry the signal, and one acts as the ground. One signal is inverted, allowing interference to be cancelled out.
Common balanced cables
This is one of the most common balanced cables. XLR connectors have three pins, each carrying a separate part of the signal. You’ll typically use these for microphones, PA systems, and studio gear.
This uses a TRS jack, which has three contact points. In a balanced setup, these carry the positive signal, the inverted signal, and the ground. You’ll often see these used for studio monitors, mixers, and interfaces.
This cable connects XLR and TRS, both of which support balanced signals. It’s commonly used to connect audio equipment while keeping the signal balanced throughout, and can also be used for microphones.
Unbalanced cables
Unbalanced cables are the simpler of the two, and they’re what you’ll see most often in instruments and home audio setups.
They use two conductor wires. One carries the signal, and the other is the ground. This works well over short distances, but it means noise can be picked up more easily.
Common unbalanced cables
This is the classic instrument cable. TS stands for tip-sleeve, which means it has two contact points. One for signal, one for ground. You’ll use this for guitars, basses, and some keyboards.
RCA cables are common in hi-fi, DJ, and home audio gear. Each connector carries a single unbalanced signal, so stereo setups use two cables. They’re always unbalanced.
This one can catch people out. The 3.5mm TRS jack might look like a balanced connector, but here it’s carrying a stereo unbalanced signal. That signal is then split into two RCA connectors. Still unbalanced from end to end.
Unbalanced curveballs
Some cables look like they might be balanced but aren’t:
This combines an XLR connector (balanced) with a TS jack (unbalanced). Because one end is unbalanced, the whole signal becomes unbalanced. Useful for certain setups, but it won’t give you the noise rejection of a fully balanced cable.
RCA to XLR Cable and XLR to RCA Cable
These can look like proper balanced XLR setups, but they’re still carrying an unbalanced RCA signal. The XLR connectors don’t make the signal balanced on their own.
Again, this can be confusing. TRS connectors can carry balanced audio, but in this case, they’re typically used for stereo signals like headphones or aux connections.
With stereo TRS, the three contact points are used differently. One carries the left signal, one carries the right signal, and the third is the ground. Because these are two separate audio channels, not inverted versions of the same signal, there’s no phase cancellation happening. That means it’s still unbalanced.
This same idea also applies to 1/4 inch TRS jacks. Even though they have the same three contact points as a balanced connection, they can still be used for stereo unbalanced signals depending on the equipment.
DI boxes
A DI box is used to convert an unbalanced signal into a balanced one. This makes it easier to send signals over longer distances without picking up unwanted noise.
You’ll often use a DI box when connecting instruments like guitars, basses, or keyboards into mixers, PA systems, or audio interfaces.
For example, a guitar outputs an unbalanced signal through a TS jack. Running that straight into a mixer over a long cable can introduce noise. A DI box converts that signal to balanced, usually via XLR, so it stays clean over longer runs.
Active vs. passive DI boxes
There are two main types of DI boxes: passive and active.
An active DI box, such as the LD Systems LDI02 Active DI Box, requires power, either from a battery or phantom power from a mixer. It uses electronic circuitry to boost and balance the signal, which makes it a better choice for passive instruments.
A passive DI box, like the SubZero Passive DI Box, doesn’t require power. It uses a transformer to convert the signal. These are simple and reliable, and they work well with active instruments, like guitars or basses with built-in preamps.
DI outputs on equipment
Some equipment already has a DI output built in, so you don’t always need a separate DI box. You’ll often find these on things like bass amps, acoustic amps, and some keyboards, usually as an XLR output. This lets you send a balanced signal straight to a mixer or PA system without needing any extra gear.
FAQs
Can you plug an unbalanced cable into a balanced output?
You can plug an unbalanced cable into a balanced output, but the connection will operate as unbalanced. As soon as any part of the signal chain is unbalanced, you lose the noise rejection benefits of a fully balanced setup.
Why don’t guitars use balanced cables?
Guitars use unbalanced cables because they only produce a single signal and don’t support phase inversion. Most amps and pedals are also built around TS connections, so unbalanced cables keep things simple and work reliably over short runs.
How do you know if a cable is balanced or unbalanced?
You can tell if a cable is balanced or unbalanced by checking the connectors on both ends. TS jacks, RCA, and most 3.5mm TRS uses are unbalanced, while balanced cables typically use XLR or TRS on both ends.
Final thoughts
Balanced vs. unbalanced cables might seem confusing at first, but it really comes down to how they’re built and how they handle noise.
We’ve looked at how to spot the difference, where each type is used, and how things like TRS connectors and DI boxes fit in.
Once you know what to look for, it’s much easier to choose the right cable and avoid unwanted noise. If you found this useful, feel free to check out our other articles!
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