TRS cables are commonly used for several purposes both in recording studios and live sound settings. Versatile and reliable, they can carry either a balanced mono signal or an unbalanced stereo signal.
Does TRS cable length matter?
The length of a TRS cable is important especially if it is being used to carry an unbalanced signal. The ground wire inside the TRS cable is designed to protect the signal. However, at longer lengths of over 20ft, it is liable to amplify electronic interference.
When a TRS cable is used to carry a balanced signal, there is less risk of this occurring.
As a result, TRS cables can be significantly longer without diminishing audio quality. The subject of TRS cable length is intertwined with many variables, and so it requires further inspection.
In this comprehensive guide, you’ll find a complete overview of TRS cables and why their length does indeed matter.
Why Length Affects TRS Cables
TRS, along with XLR, are the most popularly used type of audio cable. The name is an abbreviation of the connector type (Tip-Ring-Sleeve). The standout quality of TRS cables is their versatility, which makes them suitable for a range of audio-related applications.
If you intend to use a TRS cable in a live sound setting or a recording studio, you might find that you need to stretch the cables over long extensive lengths. Connecting an amplifier to a mixer, or sending the output from a preamp in the live room to the audio interface in the control room is two likely examples.
You’ve probably heard that when cables are used over especially long lengths, there’s a risk that audio quality could suffer. There’s certainly some truth to that statement, but it’s not quite so simple.
Various other factors will impact whether cable length is detrimental to sound quality.
- The main deciding factor is whether you are using the TRS cable to carry a balanced mono signal or an unbalanced stereo signal.
I’ll explain exactly what both of these purposes mean in a later section.
Another thing that will impact how much the length of your TRS cable matters is the quality of the cable itself. A high-end TRS cable with superior shielding is likely to handle longer lengths much more effectively than one that has sub-par shielding and is generally less durable.
As a general rule of thumb, it’s advisable to avoid using TRS cables that exceed 20ft in length. There are some scenarios where you might need to do this, which could result in audio quality being adversely affected.
Thankfully, some solutions allow you to use long cable runs while minimizing the risks. In the following sections, we’ll look into the nature of TRS cables and how their length impacts their performance.
How TRS Cables Work
TRS cables are composed of the following components:
- Copper wire cores
- PVC coating
- Tip-ring-sleeve connectors
They are generally used for one of two purposes – to carry a mono, balanced signal, or to carry a stereo, unbalanced signal. A common example of a balanced mono signal is a line input, or output, from an audio interface.
An example of a way that a TRS cable could be used to carry an unbalanced stereo signal would be the output from an audio interface to headphones. In both of these scenarios, the length of the TRS cable impacts its performance differently.
TRS connectors are built with three conductors (contact points) which are separated by a pair of insulator rings. They are often confused with TS cables because both varieties use the tip for the audio signal and the sleeve for the ground.
Check out this video on TRS vs TS cables.
However, there is one key difference between TS and TRS connectors.
The latter includes an additional ring conductor. This makes them suitable for more applications than TS cables, which are generally used to connect a line-level instrument to an amplifier, audio interface, or mixer.
TRS cables can be used for connecting to or from a balanced mono line input or output, or simply connecting a stereo output to a stereo input. In both cases, it might be necessary to use TRS cables over long distances.
The risk of interference when using a TRS cable depends largely on whether you are using it to carry a balanced mono signal or an unbalanced stereo signal. Unbalanced cables are much likelier to cause unwanted noise when used over greater lengths.
Balanced cables, on the other hand, can be used at much longer lengths without picking up interference.
In many live audio settings, sound engineers use XLR and TRS cables that exceed 20ft. On festival stages or in large arenas, these cables may even stretch over 50ft or 100ft in extreme cases.
- If you’re using a TRS cable to carry an unbalanced stereo signal, the shorter it is, the better.
If you exceed 20ft in length when using a TRS for this purpose, you’ll likely experience noticeable diminishments in audio quality.
On the contrary, using a TRS cable to carry a balanced mono signal makes the length less significant. At extremely extensive lengths, there is a risk that the cable could fall victim to unwanted electronic hum or buzz, but unless you’re pushing the boundaries, this is unlikely to be an issue.
Minimizing The Effects Of TRS Cable Length
When it comes to cable length, in the vast majority of cases, the shortest length is better. There are, however, some rare exceptions to this rule.
The function of a TRS cable, or any audio cable for that matter, is to protect the voltages as they are transferred from one point in an audio chain to another. The most effective audio cables are capable of minimizing the amount of signal loss that occurs during that transmission.
It’s impossible to provide an accurate optimal length for TRS cables because the amount of signal loss that occurs is inherently linked to several other factors.
These include whether the TRS is used to carry a balanced or unbalanced signal, the devices it is connected to, and of course, the quality of the shielding and inner components of the cable.
One thing that can be concretely stated, is that the shorter the length that a TRS cable runs, the less likely it is to experience significant signal loss or electrical interference. So wherever possible, it’s best to keep your TRS cable length to a minimum.
Unfortunately, it’s not always possible to do this.
Especially in a live music setting, the chances are you’ll need to stretch long XLR and TRS cables across the stage so that the relevant devices can be connected to a mixer, interface, preamp, or DI box.
Provided you use good quality TRS cables that have decent shielding and are in working condition, you shouldn’t need to worry too much about the length of the cable.
If you start to exceed 20ft, there is always the risk that signal loss will occur, but it’s impossible to predict without knowing the context in which the TRS cable is being used.
In the table below, you can find a breakdown of the popular audio cables used in the studio or on the stage and their most important qualities.
|Cable Type||Balanced/Unbalanced||Connector||Optimal Length|
|TRS||Both||Tip-Ring-Sleeve||Up to 20ft|
|TS||Unbalanced||Tip-Sleeve||Up to 10 ft|
|XLR||Balanced||3-Pin XLR||Up to 50 ft|
|RCA||Unbalanced||Phono Jack||Up to 10 ft|
Balanced TRS vs. Unbalanced TRS
Unbalanced signals are much more likely to experience problems when used at greater lengths. The unique thing about TRS cables is that they are multi-faceted and can be used for either type of signal.
Unbalanced cables generally consist of two connectors, each with two conductors. They are connected by a pair of wires within the cable. These are the signal wire and the ground wire.
Balanced cables, on the other hand, have three conductors in the connector, and the same number of wires inside the cable. There are two signal wires and a separate ground wire.
TRS cables feature the tip-ring-sleeve (TRS) design, which makes them suitable for both carrying a balanced mono signal, or an unbalanced stereo signal.
To conclude, if you’re using the TRS cable to carry a balanced mono signal, you don’t need to worry too much about its length. Conversely, if you’re using it to carry an unbalanced stereo signal, you should aim to keep the length as short as possible.
Can you use a TRS cable for guitar?
It is not advisable to use a TRS cable for guitar, because it has three conductors rather than the standard two conductors. The best cable for connecting a guitar to an amplifier is a TS or Tip Sleeve cable.
What is the difference between TS and TRS cables?
TRS cables can be used for balanced or unbalanced signals, while TS cables can only be used to carry unbalanced, line-level signals. This is because the TRS cable has three connector points, while TS cables only have two.
Can I use a TRS cable in an unbalanced jack?
Yes, if you plug a TRS cable into an unbalanced jack it will work effectively. The TRS cable will simply take on the role of an unbalanced cable, in the same way, it would do the opposite if the output was balanced.
Can phantom power pass through a TRS cable?
Phantom power is not exclusive to XLR cables and can pass through TRS. Therefore, when it is turned on, +48v (Phantom Power) is running to all of the selected microphone inputs. TRS cables are commonly used for line-level instruments, but they can still transmit phantom power if required.
Check out my full article on this subject. You can read it here.