# XLR vs. 1/4 in



## NewChris (Oct 22, 2013)

is there any significant difference between 3 pin XLR and 1\4 in. audio cables. Does one have better quality? Does one last longer?


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## sk8rsdad (Oct 22, 2013)

There are some pretty significance differences between balanced (XLR) and unbalanced (1/4") audio signals, mostly dealing with noise and signal loss over long distances. Balanced audio is less susceptible to noise and interference.

Cable longevity is more a function of manufacturing quality and proper care than a decision between XLR and 1/4". Pedantically speaking, XLR and 1/4" describe the connector and not the cable.


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## Focus (Oct 22, 2013)

Yes, as posted above, XLR is balanced meaning there is a non-inverted signal, and an inverted signal, when it hits your mixer, recorder, etc it amplifies the differences in the signal and eliminates the things that are the same(noise picked up from the cable will be the same in both lines), this allows xlr to be used over hundreds of feet, while 1/4" cables will start having problems after 25' or so. That is why DI boxes are used to convert 1/4 to xlr. Also pretty much all professional consoles only have XLR inputs.


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## Focus (Oct 22, 2013)

A side note. There are many cases where unbalanced 1/4 cables are used, FX, compressors, gates other outboard gear. This is all well and good, they are short distances and noise is not a problem. Also there are TRS connectors that are 1/4" but pass the same balanced signal as XLR, mostly common on prosumer gear and equipment that needs space saving of 1/4" over the larger footprint of xlr.


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## museav (Oct 23, 2013)

Focus said:


> Yes, as posted above, XLR is balanced meaning there is a non-inverted signal, and an inverted signal, when it hits your mixer, recorder, etc it amplifies the differences in the signal and eliminates the things that are the same(noise picked up from the cable will be the same in both lines), this allows xlr to be used over hundreds of feet, while 1/4" cables will start having problems after 25' or so. That is why DI boxes are used to convert 1/4 to xlr. Also pretty much all professional consoles only have XLR inputs.


Seems to be some common misunderstandings.

XLR and 1/4" are simply connectors and both can be used for either balanced or unbalanced signals. A 3 pin XLR and TRS (tip-ring-sleeve) 1/4" are essentially interchangeable in terms of the signals carried, including carrying balanced signals, however XLRs are often preferred for reasons such as the contact area, being non-shorting, making the ground contact first and more typically being locking or latching.  A TS (tip-sleeve) 1/4" is inherently limited to unbalanced signals but a TRS 1/4" or 3 pin XLR connector could be wired for balanced mono, unbalanced stereo or unbalanced mono signals.

Signal symmetry is a separate issue from balanced audio signals and you can have balanced signals with only one signal on the + conductor and without any corresponding inverted signal on the - conductor. A simple way to think about this is if that balancing and the associated noise cancellation depended on signal symmetry then you would get no noise cancellation with no signal, which is exactly when you might need it the most. Instead 'balanced' for audio signals usually refers to being impedance balanced with both conductors having equal impedance to ground. That, along with the use of twisted pair conductors, helps any noise induced in the conductors be equal in both conductors and thus be more effectively cancelled by a differential input, which looks at the difference between the signals on the two conductors and thus 'cancels' any signal common to both regardless of whether an audio signal is present. The more similar you can make any noise induced in each conductor via techniques such as impedance balancing and twisted pairs, the more effective the resulting noise cancellation.

One of the primary purposes of DI boxes is to reduce the signal level to allow line level sources to be run over microphone lines. DI boxes also typically provide some electronic isolation. However, they are not used to convert unbalanced signals to balanced signals of the same level.

So to the OP, since XLR and 1/4" are just connectors and there are variations on them, e.g. unbalanced mono TS 1/4" versus balanced mono or unbalanced stereo TRS 1/4", the connector alone does not tell you about the cable. A 1/4" TRS to 1/4" TRS and XLR to XLR cable using the same cable and wiring are essentially comparable and it really comes to which works best for the application. It is fairly common in some installed systems to use XLR connections for microphone level signals and 1/4" connections for line level signals in order to clearly differentiate the two but as far as equipment interconnects there is no significant difference other than preferences in the physical connections.


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