What Happens if You Plug a TRS Cable Into a TS Jack?

When you don’t have a TS cable, you might be tempted to use a TRS in its place. While this works in carrying an audio signal from point A to B, there are a few limitations to expect. So, what happens if you plug a TRS cable into a TS jack?

If you plug a TRS cable into a TS jack, it can produce an unbalanced audio signal. The durability of the TRS cable may also be compromised, and the connection may be unreliable or of lower quality. 

Read on for an in-depth discussion on substituting a TS cable for a TRS cable comes with the above limitations. 

The Audio Signal Will Be Unbalanced

One of the primary issues with plugging a TRS Cable into a TS jack is that it results in unbalanced audio. Unbalanced audio is typically more prone to external noise created by electromagnetic interference than balanced audio, especially when running long cables.

But don’t TRS cables typically carry balanced audio? They almost always do. Still, plugging one into a TS jack can “unbalance things.”

To help you understand why this happens, let’s quickly review both types of cables to determine where the unbalancing comes from. This way, you can make sense of why using a TRS cable as a TS substitute yields unbalanced audio without having to take my word for it.

Inside of TS Cables

Typically, TS audio cables comprise several metal wires confined in a rubber casing. The innermost metal wire is usually a core conductor wire made of copper or another conductive metal. The conductive wire is engulfed by core insulation, which is surrounded by shielding. 

The shielding has two key roles. First, it acts as a ground wire to prevent unwanted fire breakouts and electric shocks. Second, it helps minimize electromagnetic noise interference. 

Wall sockets, lights, and other electrical appliances/equipment emit a 60Hz high-frequency sound. When your cables pick up these sounds, the result is an unwanted hum or buzz from your speaker/amp.

Inside of TRS Cables

Even though the shielding I mentioned above does a decent job reducing electromagnetic noise interference, it is not entirely foolproof. 

This is where balanced cables like the TRS come in. 

While the TS comes with the standard cable design described above (i.e., one insulated conductor wire plus shielding), the balanced TRS has an additional wire. Put otherwise, it has two intertwined signal wires (the hot and cold wires) protected by the standard shielding you’ll find in TS cable.

Such a setup is much more effective at reducing electromagnetic interference.

The cold and hot pick up electromagnetic interference noise. When picked up, the noise is carried as a positive signal on one of the conductor wires and a negative signal on the other. So now you have two copies of the same noise signal, but one has a positive charge and the other negatively charged.

This is different from how desirable audio is carried in the hot and cold conductors. The two wires have copies of the same signal, but the polarity is inverted at the source. When it reaches the receiving gear, it’s re-inverted back to its original polarity such that the signals match. 

During this re-inverting, the noise signal’s negative and positively charged copies don’t match because they weren’t initially inverted at the source like the desirable audio. They entered along the length of the cable as opposed to being generated by an instrument or device.

So even after the flipping, there are both negative and positive copies of the noise signal. Thus, the two signals cancel each other out to eliminate the noise (think how +5 added to -5 equals zero), leaving you with clean desirable audio.

This, albeit with a bit of oversimplification in the explanation, is how TRS cables deliver balanced audio free of electromagnetic interference.

For more information, check out which is better for recording studios: XLR and TRS.

Where Does Unbalancing Come From?

An unbalanced audio signal can come from the cable or the jack. However, most unbalancing that results from plugging a TRS cable into a TS jack has more to do with the jack than the cable itself. 

A TS jack typically puts out an unbalanced mono signal. A balanced cable can only deliver a balanced audio signal when plugged into a balanced output jack. Even with the balanced cable technology of a TRS, you will still get unbalanced audio if you plug it into a TS jack. The mono signal produced by the jack doesn’t allow the TRS to work its magic.

Why Unbalanced Audio Is an Issue

So far, we’ve established that unbalanced audio is more susceptible to Radio Frequency Interference (AKA electromagnetic interference). However, this isn’t the only reason why balanced audio is preferred over unbalanced audio.

Compared to its balanced counterpart, unbalanced audio comes up short in terms of:

• Loudness and headroom. With an unbalanced connection, some of the signals may be lost along the length of the cable. You’ll need to turn your device volume settings higher to achieve the desired output volume when this happens. The audio dynamic range may also be compromised.
• Canceling out harmonic distortion. Sometimes, your speaker or amplifier may create subtle harmonic distortion. A balanced connection cancels out this type of sound distortion better than an unbalanced connection, helping preserve the original audio signal’s clarity and integrity.

Check out: How To Hide Wires in a Recording Studio

The Connection May Be Unreliable

Unbalancing issues aside, plugging a TRS cable into a TS jack may create an unreliable connection. To understand why this may happen, it’s essential to understand the components of TRS cables and TS jacks.

TRS is short for Tip, Ring, and Sleeve. These three terms refer to the specific parts of the plug where the corresponding conductors of a TRS cable are supposed to make contact inside the jack. 

On the other hand, a TS jack plug only has a Tip and Sleeve because a TS cable has two conductors instead of the TRS’s three. 

A TRS cable plug and jack have three contact points, while a TS’s jack and plug have two. By having a TRS plug in a TS jack, you’re taking a gamble on whether the Ring makes contact. This results in an unreliable connection that’s more prone to handling noise, which isn’t ideal.

The Cable’s Durability May Be Compromised

The last potential problem with using a TRS cable as a TS is reducing the cable’s longevity. This is particularly true for individuals who use TRS cables as guitar cables or other applications where the cables get flexed frequently.

The TS cable’s tensile is typically higher than that of a TRS cable. Cable manufacturers are well aware that TS cables are likely to get flexed in use, so they design them with breakage resistance in mind. 

Alternatively, TRS cables typically sit relatively undisturbed in use, so breakage resistance isn’t emphasized as much during manufacturing. So by using a TRS cable as a guitar cable, for instance, you’re subjecting it to abuse that it wasn’t designed for, effectively shortening its service life.

Final Thoughts

As you can see, plugging a TRS cable into a TS comes with its fair share of challenges. While this kind of setup will still work, you’ll likely have to make do with an unbalanced audio signal, limited cable durability, and an unreliable connection.

If you can’t stomach these drawbacks, stick to using a TRS cable in a designated jack. Alternatively, purchase a TRS> TS converter at your local store or search for one online.

Sources

• Sweetwater: What’s the difference between a TS cable and TRS cable?
• Producerhive: TS vs TRS Cables (Differences Explained Simply)
• Music.stackexchange: Is there any reason not to use TRS cables for typically TS applications? – Music: Practice & Theory Stack Exchange
• Sweetwater: What is the difference between balanced or unbalanced?
• Musicianshq: TRS cable for guitar? Why this cable is a waste of your cash | Musician’s HQ
• Mediacollege: Balanced Audio Cable
• AViom: What’s the Difference Between Balanced and Unbalanced?.