Balanced and Unbalanced Connections (Finally) Explained

While setting up a bunch of audio gear for a venue or studio, you’re going to come across balanced and unbalanced cables. But, what exactly is the difference between these so-called symmetrical and a-symmetrical connections? What kind of plugs do you need to use and are balanced cables pretty much the same as stereo-cables? All of these nagging questions shall be answered in the following blog.

What is a Balanced Connection?

A balanced connection, or symmetrical connection, prevents unwanted noise and hum. Balanced connections are mostly used when large distances need to be bridged, especially when carrying weak signals like those of microphones. For a balanced connection, both linked devices need to have a balanced socket. This ensures that the emitted signal is duplicated: one is sent normally and a copy is sent with reversed polarity. The device at the other end then receives both signals separately, re-reverses the polarity of the copied signal, then combines the two signals. The point of this switching-trick is that the original signal becomes twice as loud and that any noise picked up while travelling along the two wires in the cable disappears.

What is a Balanced Connection?

How can you Tell the Difference Between a Balanced and an Unbalanced Cable?

For a balanced connection (symmetrical), you’re going to need a cable with three wires and a plug with three contact points. The most frequently used balanced plugs are XLR and 6.3mm jack plugs. XLR plugs have a round end with three visible and separate contact points. An XLR cable usually comes with a female plug with three holes at one end and a male plug with three pins at the other end. The audio signal is collected at and sent from the female end, through the cable to the male end. While XLRs are the standard connections used for microphones, they’re also used for line-signals. The 6.3mm or quarter-inch TRS jack plugs are a little more widely familiar. The plug is split into three segments: the tip, ring and sleeve – hence, ‘TRS’. The unbalanced version of a jack plug is only split into the tip and sleeve and are therefore referred to as TS jacks. Another example of an unbalanced plug is an RCA connector. These are also known as ‘tulip’, ‘cinch’ or ‘phono’ connectors and are normally used to connect up stereo or DJ gear.

How can you Tell the Difference Between a Balanced and an Unbalanced Cable?

What is the Difference Between a Stereo-Plug and a Balanced Plug?

The TRS plug used for balanced connections is precisely the same plug that you’ll find on the end of the cable for something like a set of headphones and this is what causes the confusion. While a balanced signal and a stereo signal are not the same thing, both principles use three-wire cables and plugs with three contact points. The big difference is that a balanced cable has an earth, a plus and a minus, while a stereo cable has an earth, stereo left and stereo right. The two signal wires in a TRS cable can perform the switch-trick described above to send a balanced signal, while it can also be used to send two different signals to the left and right drivers of your headphones or any other stereo device. Stereo cables are not quite as flexible.

Are Stereo Signals and Balanced Signals Interchangeable?

In a word, no. If you were to try to connect the stereo-output of a smartphone to the balanced input of a mixer, the mixer will flip the polarity of one of the stereo signals and then combine it with the other. This basically removes anything that was sitting in the middle of the stereo-image of the track – so you suddenly hear a song missing the singer, the bass and kick drum. Sometimes, even weirder stuff can happen. If you try to send a balanced signal from a mixer to the stereo input of something like a PC, both the left and right will sound the same but one of them will have a reversed polarity, creating a bizarrely hollow sound that seems to come from everywhere but the speakers.

Are Stereo Signals and Balanced Signals Interchangeable?

Why are Unbalanced Connections Still Used?

Basically, it comes down to the fact that the circuit for a balanced connection is more expensive than that of an unbalanced connection. This can sometimes be the point at which some manufacturers will cut corners. Also, the line-signals sent by instruments or devices like keyboards are much louder than those sent by a microphone so the signal-to-noise ratio is not in much danger of becoming imbalanced, so sometimes, a balanced connection is simply not necessary. As such, it must seem pretty strange that, more often than not, passive, weak-signalled instruments like electric guitars and basses still use an unbalanced connection. People have tried to experiment with balanced guitars in the past but quickly discovered that, due to the high impedance of the instrument, a balanced circuit caused too much of a negative influence over the interaction between the guitar and amplifier.

How Can You Make an Unbalanced Signal Balanced?

An unbalanced signal can be converted to a balanced one with the help of a ‘direct injection box’, better known as a D.I. box or just D.I. If you’ve ever played a live show, you’ll have encountered at least one of these handy little boxes littering the stage, since they’re often used to balance the signal of electro-acoustic guitars or electric basses. Doing this means, that a distance of tens of metres can be bridged without any unwanted noise or hum. To use a D.I., however, the signal must be sent to a balanced input. Most of the time, a D.I. is connected via a microphone input which is usually balanced. It’s also fine to connect an unbalanced cable to a balanced input. While the connection won’t be balanced, the signal will come through normally.

How Can You Make an Unbalanced Signal Balanced?

» 6.3mm jack cables (balanced/stereo)
» 6.3mm jack cables (unbalanced/mono)
» 6.3mm to 3.5mm jack cables (mono/stereo)
» XLR cables
» XLR male to 6.3mm jack cables/plugs
» XLR female to 6.3mm jack cables/plugs
» RCA cables
» RCA to 6.3mm jack cables/plugs
» RCA to XLR cables/plugs
» Audio cable per meter/roll

» How To Connect Your Speakers To Your Audio Equipment» How to Connect your Speakers to your Audio Equipment<
» How to connect studio monitors» How to Connect Studio Monitors<

28 responses
  1. James says:

    Hi, Acoustic guitar 1/4 to ‘Tc Helicon Play Acoustic (effects box), from effects box 25ft of XLR ( only has an XLR out) but need to covert back to 1/4 to input into my amp.

    Do I need a box to properly covert back To 1/4 and retain the noise cancelling benefits of a balanced signal and retain audio volume/quality.

    Thanks

    • If you want to maintain a balanced connection between the output of your TC Helicon box and your amp you need something to convert from balanced XLR to unbalanced 1/4 jack. You could use a re-amp box like the Radial ProRMP. This is basically an inverted DI box. Use a short 1/4 jack cable to connect the unbalanced output of the ream box to your amp.

      You could also use an ordinary DI box and invert it yourself by using an adapter. So the input becomes the output and the output becomes the input.

  2. Lucas Askaroff says:

    Hi, thanks for getting back to me.
    The headset is a gaming headset by Steelseries, the nova pro wireless. I reached out to them and asked what the extra pole was used for and they said it was for better immunity from echo. I imagine the 5th pole is a separate ground for the mic then. With 2 grounds and a mic that would allow it to use a balanced connection no? It’s only got the one mic so not stereo mics.

  3. Lucas Askaroff says:

    Hi, I have a headset with a mic that has a 3.5mm 5 pole trrrs jack. Can this be used with a balanced connection? or does the mic mean the wiring in the headset wont allow it?

    • Honestly, this is the first time I’ve ever heard of a trrrs connector. I’m kind of curious, which brand/model is it? Whether it’s a balanced connection or not really depends on how your headset is wired. Two of the five connections are probably meant for the unbalanced stereo signal for the headphones. I suppose the other two are for the mic. It could be balanced or it could be a stereo mic. Both cases are very unusual in a headset.

  4. Phil says:

    I am running 3 keyboards into a mixer into 3 separate channels – each keyboard has its own respected channel. The distance requires a 30’ cable. It works, but I am getting unwanted humming noise from all 3 cables. They are unbalanced cables going into the line input. I am coming out of the mono input on the left input of each keyboard’s input. Mind you I didn’t by high end cables cuz that length is expensive and I noticed the cable’’s awg seems thinner than usual. Could that be the problem? Would I just be better off using a balanced 1/4” to xlr cable to each channel on the mixer instead?

    • If your keyboards have balanced outputs, then balanced cables are definitely a worthwhile investment, especially if you need to cover large distances.

      If your keyboards have unbalanced outputs I’d like to suggest using DI boxes. A DI box turns an unbalanced signal into a balanced signal. Connect each keyboard to to a separate DI box using a very short unbalanced cable. Connect each DI box output to the mixer with a balanced cable.

  5. Toni says:

    What will happened if I connect my headset from an Balanced output 4.4mm to unbalanced input 3.5mm will I get any sound improvement?

    ex. ifi zen dac v2 Balanced output 4.4mm to Master dynamic MW65 unbalanced 3.5 mm with 4.4mm to 3.5mm cable

  6. Tony says:

    Hi there! Is there any way to tell if a 1/4″ port on a cheap mixer (both line in and line out port) is balanced? The manual does not indicate anything. It is a Moukey Mamx3; the in and out ports can be switched between mono and stereo, so I was thinking that MIGHT mean they are balanced ports (since they can deal with the 3rd wire for a stereo connection – would that automatically mean they can deal with the 3rd wire for a balanced mono connection when switched to mono?) Or does the port have to be “smart” enough to do that when switched to mono, and if it isn’t it just ignores the 3rd wire?

    • That is a very strange device you have there. Let’s see if I can wrap my head around this…

      To identify a balanced or unbalanced output:
      -Record one of the outputs to a stereo track using a TRS – TRS or a TRS to 2 x TS cable (depending on your recording device)
      -If the two channels of the stereo recording are identical but the polarity is inverted, the output is balanced
      -If one of the channels is missing, the output is unbalanced

      To identify a balanced or unbalanced input
      -Connect a balanced mono source to one of the inputs and set the corresponding switch to stereo.
      -press the ‘1-8 channel output Mix L-R’ button
      -Record both outputs to a single stereo track
      -If the two channels of the stereo recording are identical but with opposing polarities, the input is balanced
      -If the two channels of the stereo recording are identical and the polarity is also the same, the input is unbalanced

      Bare with me, I’m not enirely sure how the outputs on this device work. I assume both A and B are unbalanced stereo outputs where inputs 1-4 go to output A and inputs 5-8 go to output B. I might be wrong though.

      A simple test to see if a input or output has 2 or 3 connections is to plug in a TRS plug. If there is 1 click it has 2 connections and if it there are 2 clicks the must be 3 connections.

  7. Joep says:

    I have a diatonic accordeon, it sends two signals: bass and melodies. It has only one stereo jack output, so the left can be used for basses and right for melodies. On stage i used to use a stereo jack to two mono jack splitter cable and they went into two di’s. Problem was: these cables tend to break and more important: sound people always mess up the balance between bass and melodies, i want to be in control myself. so, i found a solution: i now use a stereo jack to xlr. It gives only one signal and it combines the basses ans melodies on one cable. Soundwise its ok, because the signals dont bleed to eachother there are no phasing problems because of the reversed polarity. But: it is unbalanced also because of this. If i put it into a di, one of the channels ( bass or melodies) isnt coming trough. Why is this? And do you know a solution in which i can use one mono signal but make it balanced?

    • A DI input has only two pins and your jack to XLR cable has three. This is why one of your signal is lost. I think the best solution is to keep using stereo jack to dual mono jack cables (maybe a higher quality cable so it doesn’t break) and merge them before you send them to the sound engineer. You can do this by plugging them into a small personal mixer like the Behringer Xenyx 802 and leave the pan knobs centered. The sound engineer will therefore only need one of the stereo outputs of this mixer and won’t be able to mess up the balance. A more simple and elegant (but also more expensive) solution is to use the Radial JDI instead of the Behringer mixer. The JDI is a passive DI with a merge function. Press the merge button and the link output will turn into a second unbalanced input. Both unbalanced inputs will be merged and will show up at the output as a single balanced singnal.

  8. Jack Braisher says:

    Is that a typo, did it mean to say balanced?
    Eg (connect the stereo-output of a smartphone to the “balanced” input of a mixer)?

    “If you were to try to connect the stereo-output of a smartphone to the “unbalanced” input of a mixer, the mixer will flip the polarity of one of the stereo signals and then combine it with the other”

  9. Les Eaves says:

    Thanks for the reply – I am connecting to the sounds system using 1/8″ input (line in I suppose). I can barely hear anything. However when I partially remove the 1/4″ output plummeted from the instrument the sound is much louder. AM I using the right cable? The balanced or unbalanced stuff confuses me?

    • Eelco | Bax Music says:

      Hi Les,

      My guess is that the cable isn’t the issue, but the input that you use is. You don’t have to worry about what is balanced and unbalanced. This headphone output is stereo jack, so you’ll have to use a jack cable with TRS plugs (with two black rings, like this one). If you use another cable like TS (one black ring) or TRRS (three black rings) then that might be why the sound is louder if you partially pull the plug out.

      I’ll state that a Line level input expects a louder, stronger sound signal then most headphone outputs can provide. It might work in a pinch (sometimes), but you usually don’t want to use a headphone signal for a line level device.

  10. Les says:

    I have a headphone output on a Yamaha YDS-150 digital Saxophone than I am trying to connect to a Mixer(amp). I used an 1/8″ to 1/4″ TRS cable and I get very low volume. When I partially pull out the 1/8″ plug from the headphone output of the sax it appears the ovum his normal through the amp. I was thinking of getting a 1/8″ plug to XLR. Would this solve the issue. I supposed the output of the Sax (headphone port ) is balanced so Im not sure what I need to use hear. Any help would be appreciated. Thanks!

    • Eelco | Bax Music says:

      Hi Les,

      It’s possible that the headphone signal is to low for a line level input on a mixer. It’s usual for a headphone signal to be of a lower, more quiet volume. If you use the output for a regular headphone, is the sound level okay?

      What input do you use on the mixer? If you use an instrument input, like a Hi-Z input, then the volume would be very low because of the high impedance of the input. You’ll want to use an AUX-input that’s used for CD players, MP3 players and those types of devices. A regular line level input should also suffice without impacting the volume to much.

  11. Patrick says:

    How can I convert a balance signal to unbalance signal. I use Aux out from mixer to pc input via USB sound box with noise. From different forum said may caused from balance signal. I’m not sure how to remove the noise signal. Please help.

    • If I understand correctly, you want to connect the balanced aux output of your mixer to the unbalanced input of your audio interface. With the ART DTI you can transform balanced signals to unbalanced signal and vice versa. But before you buy anything, please check if the noise doesn’t come from a different component in you audio chain. Maybe the gain of your mixer is too high, maybe the usb port you’re using for the audio interface transfers hard disk noise.

  12. Alan Evans says:

    Now here’s a real dumb question from an absolutely non technical poor player of the guitar and various other instruments but who loves to make up songs (also a very old rocker)
    I have a Tascam DP24 recorder and find that the recorded volume from a mic (shure58) comes out super low; I have a Mackie mix8 that’s been gathering dust for years; can I run the mic through this to the recorder, will it help and how do I hook it up.
    Or is there a simpler inexpensive solution. Ya I know there’ll be some head shaking and eye rolling amongst you, just pretend you’re dealing with your granddad and its the first time he’s ever seen these things lol and thanks.

    • Are you sure you have selected the right input source? You can set the input source on the back of your DP-24SD. I doubt your Mix8 will make much difference. Maybe it has slightly more powerful pre amplifiers than the DP-24SD but it’s not going to be a huge difference. You could add an inline preamplifier like the Triton Audio FETHead. This device needs to be powered so don’t forget to engage phantom power.

  13. ian fish says:

    h-i get the difference between a balanced jack and a stereo jack, but how can you tell them apart by looking at them-thanks

    • Hi,

      There is no difference!

      It doesn’t matter which word you use, it’s the same jack.

      Sometimes you use this kind of jack for stereo signals, sometimes you use it for balanced signals.

      Marnix | Bax Music

  14. Ken McCurdy says:

    I have set of audio-texhnica, ATH-MSRb headphones with an optional balanced cord with 4.4mm male end.I would like to connect it to my AVR using a 6.35mm male plug withe a 10ft.cable. I have a stereo cable. Can I use adaptors or do I need a balanced cable, that is, with 3 conductors and a ground. Or should I just be content with what I have?

    • Eelco | Bax Music says:

      Dear Ken,

      Unfortunately, 4.4 mm isn’t a very common connector size. Most of our adapters only have 3.5 mm or 6.3 mm connectors. If you can find a TRS-adapter that accepts 4.4 mm connector plugs, then you should be able to connect your headphone to your AVR, no problem. If you can’t find a TRRS-adapter, then it isn’t an issue if you plug a TRRS-jack into a TRS-port. You’ll probably just lose the microphone or remote capabilities of your headphones.

      Do note that if the audio output on your AVR isn’t a headphone output but a regular line output, the sound will be quite loud on your headphones!

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