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{{short description|Electrical connector for professional audio and lighting}}
{{Use dmy dates|date=July 2021}}
[[File:Xlr-connectors.jpg|thumb|upright=1.35|XLR3 cable connectors female (left) and male (right)]]

The '''XLR connector''' (also called a '''Cannon plug''' or '''Cannon connector''') is a type of [[electrical connector]] primarily used in [[professional audio]], video, and [[stage lighting]] equipment. XLR connectors are cylindrical, with three to seven connector pins, and are often employed for analog [[balanced audio]] interconnections, [[AES3]] digital audio, portable [[intercom]], [[DMX512]] lighting control, and for low-voltage [[power supply]]. XLR connectors are part of the international standard for dimensions, [[International Electrotechnical Commission|IEC]] 61076-2-103.<ref>{{cite web|url=http://webstore.iec.ch/webstore/webstore.nsf/Artnum_PK/31858 |title=''IEC 61076-2-103 ed1.0. Connectors for electronic equipment - Part 2-103: Circular connectors - Detail specification for a range of multipole connectors (type 'XLR')'' |publisher=International Electrotechnical Commission |date=3 August 2004 |access-date=2012-03-23}}</ref> The XLR connector resembles the [[DIN connector]], but is larger, more robust and physically incompatible.

The generic term XLR began as a trademark of [[Cannon Electric]], with the letters standing for X model connector with an added latch (L) feature, and resilient (R) [[neoprene]] rubber surrounding the female contacts.<ref name="Rayburn"/>

== History and manufacturers ==
[[File:Group of XLR connectors PICT6918.jpg|thumb|Male and female XLR connectors with different numbers of pins]]

The XLR connector was invented by [[James H. Cannon#James H. Cannon|James H. Cannon]], founder of the [[Cannon (company)|Cannon Electric]] company, Los Angeles, California. The XLR connector originated from the ''Cannon X'' series of connectors; by 1950, a latching mechanism was added to the connector, which produced the ''Cannon XL'' model of connector, and by 1955, the female connector featured synthetic-rubber insulation [[Neoprene|polychloroprene (neoprene)]], identified with the part-number prefix ''XLR''. There was also the ''XLP'' series of connectors with hard plastic insulation, but the XLR model name is commonly used for all of the variants.<ref name="Rayburn">{{cite web |url=http://www.soundfirst.com/xlr.html |title=A brief history of the XLR connector |last=Rayburn |first=Ray |authorlink=Ray Rayburn |date=16 December 2008 |work=Sound First |archive-url=https://web.archive.org/web/20101225010508/http://www.soundfirst.com/xlr.html |archive-date=25 December 2010 |url-status=live }}</ref><ref name="McGuire 2013 49">{{cite book|last1=McGuire|first1=Sam|last2=Pritts|first2=Roy|title=Audio Sampling: A Practical Guide|year=2013|publisher=Taylor & Francis|isbn=978-1136122620|page=49}}</ref><ref name="AES">[http://www.aes.org/par/c/#XLR AES Professional Audio Reference description]</ref>

Originally, the ITT Cannon company manufactured XLR connectors in two locations: Kanagawa, Japan, and Melbourne, Australia. The Australian factory was sold to Alcatel Components in 1992 and then acquired by [[Amphenol]] in 1998. Later, the [[Switchcraft]] corporation manufactured compatible connectors, followed by the [[Neutrik]] company, which made improvements to the connector, and produced a second-generation design (the X-series) that had only four parts for the cable connector, and eliminated the small screws used in the models of XLR connectors made by Cannon and Switchcraft, as well as in earlier Neutrik series.

== Design ==

XLR connectors are available in [[Gender of connectors and fasteners|male and female]] versions in both cable and chassis mounting designs, a total of four styles. This is slightly unusual as many other connector designs omit one of the styles (typically a chassis mounting male connector).

The female XLR connectors are designed with a longer metal sleeve to first connect pin 1 (the earth pin), before the other pins make contact, when a male XLR connector is inserted. With the ground connection established before the signal lines are connected, the insertion (and removal) of XLR connectors in live equipment is possible without hearing a static pop (as usually happens with, for example, [[RCA jack|RCA]] connectors).

The number of pins varies. As of 2016, XLR connectors are available with up to 10 pins,<ref>{{cite web|url=http://www.prosoundweb.com/mobile/article/neutrik_debuts_10-pin_xlr_connector/|title=Neutrik Debuts 10-Pin XLR Connector - ProSoundWeb|date=20 October 2015|website=prosoundweb.com|access-date=17 April 2016|archive-date=25 April 2016|archive-url=https://web.archive.org/web/20160425135933/http://www.prosoundweb.com/mobile/article/neutrik_debuts_10-pin_xlr_connector/|url-status=dead}}</ref> and mini XLR connectors with up to eight. XLR connectors from different manufacturers will intermate, with the exception of six-pin models, which are available in two incompatible designs. The older [[Switchcraft]] six-pin design adds a center pin to the standard five-pin design, whereas the newer [[Neutrik]] design is a different pattern. The [[Switchcraft]] six-pin female will accept a standard five-pin male plug whereas the Neutrik six-pin design will not. Neutrik offers connectors in both six-pin designs.

The terminology for labeling the corresponding members of a pair of mating connectors follows the usual rules for the [[coaxial power connector#Connector construction and terminology|gender of connectors]]: a 'male' connector is the one with pins on the ''smallest'' element, 'female' has corresponding receptacles. A 'plug' connector enters the 'socket' connector, judged by the largest element. For most other cable types, plugs are male and sockets are female.{{efn-lr|This was not the case for the [[#Obsolete patterns|obsolete]] mains inlet connector, as that used shrouded pins.}} XLR cables are unusual in that, at least in audio applications, all four combinations of male and female, plugs and sockets are equally common. XLR connections often employ many free female connectors and panel-mounted male jacks. There is a loose convention for audio work that signals are generated by equipment with male pins and transmitted to those with female receptacles. The external diameter of a Neutrik male XLR plug is 19mm,<ref name="Neutrik">{{cite web |title=XLR Connectors product guide |url=https://www.neutrik.com/media/10098/download/01%20NEUTRIK%20Section%20XLR%20Connectors%20PG%20EN%20202202-V23_opt.pdf?v=7 |publisher=Neutrik AG |access-date=10 March 2025 |archive-url=https://web.archive.org/web/20240823181723/https://www.neutrik.com/media/10098/download/01%20NEUTRIK%20Section%20XLR%20Connectors%20PG%20EN%20202202-V23_opt.pdf?v=7 |archive-date=2024-08-23 |page=5 |url-status=live}}</ref> giving a circumference of {{Convert|59.7|mm||abbr=on}}.  The plug section of a Neutrik female XLR connector has a diameter of 15.8mm.<Ref name="Neutrik" />

== Current patterns and applications ==

=== Three-pin (XLR3) ===

Three-pin XLR connectors are by far the most common style, and are an industry standard for [[balanced audio]] signals. The great majority of professional [[microphones]] use the XLR connector. In previous years, they were used to connect loudspeakers to their amplifiers, for instance by [[Trace Elliot]] in its bass enclosures.<ref>{{cite book |url=https://books.google.com/books?id=I97xJYZC2lIC&pg=PA110 |page=110 |title=The Bass Handbook |first=Adrian |last=Ashton |publisher=Hal Leonard Corporation |year=2006 |isbn=0879308729}}</ref> The XLR could accept 14&nbsp;AWG ({{Convert|1.6|mm||abbr=on|disp=or}}) wire with a current-carrying capacity of 15 amps, suitable for most loudspeakers, but they have been superseded by the [[Speakon connector]] for professional loudspeakers. The Speakon connector accepts larger wire and carries more current, and it provides a better shield for the contacts, which may carry dangerous voltages when connected to an amplifier.<ref>{{cite book |url=https://books.google.com/books?id=GSZ_sQID9GwC&pg=PA138 |page=138 |title=The Live Sound Manual |first=Ben |last=Duncan |publisher=Hal Leonard Corporation |year=2002 |isbn=0879306998}}</ref>

Three-pin XLR connectors are used to interconnect powered speakers with line-level signals used for [[Public address system|PA]] system applications.

Rechargeable devices exist that use three-pin XLR connectors. These can be found on electric powered mobility [[wheelchair]]s and scooters. The connectors carry from 2 to 10&nbsp;amps at 24&nbsp;volts.{{Citation needed|date=November 2020}}

An obsolete use for three-pin XLR connectors was for [[MIDI]] data on some Octave-Plateau synthesizers including the [[Voyetra-8]].

The three-pin XLR connector is commonly used for [[DMX512#Connectors|DMX512]], on lighting and related control equipment,<ref name="DMX512 Standard Pinouts">{{cite web |url=http://www.dmx512.com/web/light/dmx512/pinouts.htm |title=DMX512 Standard Pinouts |access-date=2012-03-12}}</ref> particularly at the budget / DJ end of the market.  However, using three-pin XLR connectors for DMX512 is specifically prohibited by section 7.1.2 of the DMX512 standard.<ref name="tsp.plasa.org">{{cite web|title=American National Standard E1.11 – 2008|url=http://tsp.plasa.org/tsp/documents/docs/E1-11_2008R2013.pdf|website=PLASA Standards|publisher=[[Professional Lighting and Sound Association]]|access-date=26 October 2014|page=12|archive-url=https://web.archive.org/web/20141026174610/http://tsp.plasa.org/tsp/documents/docs/E1-11_2008R2013.pdf|archive-date=26 October 2014|url-status=dead}}</ref> Use of the three-pin XLR in this context firstly presents a risk of damage to the lighting equipment should an audio cable carrying 48-volt phantom power be accidentally connected.

=== Four-pin (XLR4) ===

Four-pin XLR connectors are used in a variety of applications.<ref name="pinouts.ru">{{cite web|url=http://pinouts.ru/Home/xlr4_pinout.shtml|title=Professional audio / entertainment devices 4 pin XLR connector pinout diagram @ pinoutguide.com|website=pinouts.ru}}</ref>

They are the standard connector for [[intercom]] headsets, such as systems made by [[Clear-Com]] and [[Telex Communications|Telex]]. Two pins are used for the mono headphone signal and two pins for the unbalanced microphone signal.<ref>{{cite web |author1=Clear-Com Intercom Systems |author1-link=Clear-Com |title=PARTY-LINE INTERCOM – SYSTEM INSTALLATION MANUAL |url=https://clearcom.com/DownloadCenter/manuals/Encore/Clear-Com_PL-Pro_Installation_Manual.pdf |website=clearcom.com |access-date=13 September 2025 |archive-url=https://web.archive.org/web/20250913132048/https://clearcom.com/DownloadCenter/manuals/Encore/Clear-Com_PL-Pro_Installation_Manual.pdf |archive-date=13 September 2025 |date=April 1998}}</ref>{{Rp|7}}

Another common use is for DC power connections for professional film and video cameras and related equipment. Some desk microphones with LEDs use them. The fourth pin is used to power the LED indicating that the microphone is on.<ref name="sennheiser">{{Cite web | url=http://www.sennheiser.com/sennheiser/home_en.nsf/root/professional_wired-microphones_installed-sound_504792?Open&row=2 | archive-url=https://web.archive.org/web/20110206161150/http://www.sennheiser.com/sennheiser/home_en.nsf/root/professional_wired-microphones_installed-sound_504792?Open&row=2 | url-status=dead | archive-date=2011-02-06 |title = Sennheiser Worldwide - MEG 14-40-L B}}</ref>
Other uses for the four-pin XLR include some scrollers (colour-changing devices for stage lighting), [[AMX192|AMX]] analog lighting control (now obsolete) and some [[pyrotechnic]] equipment.{{Citation needed|date=November 2020}}

Four-pin XLR is used for balanced headphone connections, from a balanced amplifier, where there is no common earth between the two channels. Connection diagram: 1. left channel (+) phase; 2. left channel (−) phase; 3. right channel (+) phase; 4. right channel (−) phase.<ref>{{cite web | url=https://www.head-fi.org/threads/diy-headphone-cable-adapter-questions-xlr-4-pin-female-mini-to-4-pin-female.895798/ | title=DIY Headphone Cable Adapter Questions: XLR, 4 Pin Female Mini to 4 Pin Female | date=19 December 2018 }}</ref>

=== Five-pin (XLR5) ===

Five-pin XLR connectors are the standard for [[DMX (lighting)|DMX512]] digital lighting control.<ref>{{cite web |url=http://pinouts.ru/Home/dmx-512_pinout.shtml |title=DMX (DMX512) pinout |access-date=2012-03-08}}</ref>

Other common uses are for dual-element or stereo microphones (two balanced audio signals with a common ground) and stereo intercom headset (three pins for the stereo headphone signal - left, right, and ground, and two pins for the unbalanced microphone signal).{{Citation needed|date=November 2020}}

Additionally, five-pin XLR is commonly used for DC power in audio equipment.{{Citation needed|date=November 2020}}

XLR 5 is used in [[List of aviation headset connectors|aviation headsets]], where it can supply power for [[active noise cancellation]].

=== Six-pin (XLR6) ===

Six-pin XLR connectors are used for dual channel intercom systems<ref>{{cite web|title=Clear-Com RS-602 beltpack|url=http://www.clearcom.com/product/partyline/wired-beltpack/rs-602/descriptions|access-date=2012-03-16|archive-url=https://web.archive.org/web/20180904225732/http://www.clearcom.com/product/partyline/wired-beltpack/rs-602/descriptions|archive-date=4 September 2018|url-status=dead}}</ref> and [[stage lighting]] control applications.<ref>{{cite web|title=ETCLink Documentation |url=http://www.etcconnect.com/Community/wikis/products/etclink.aspx |url-status=dead |archive-url=https://web.archive.org/web/20111221152445/http://www.etcconnect.com/Community/wikis/products/etclink.aspx |archive-date=21 December 2011 }}</ref>{{Unreliable source?|date=January 2012}}<ref>{{cite web|title=ETC RFU Documentation |url=http://www.etcconnect.com/Community/wikis/products/rfu.aspx |url-status=dead |archive-url=https://web.archive.org/web/20111221152501/http://www.etcconnect.com/Community/wikis/products/rfu.aspx |archive-date=21 December 2011 }}</ref>{{Unreliable source?|date=January 2012}}<ref>{{cite web|title=ETC RFU and ETCLink Pinout |url=http://www.etcconnect.com/Community/wikis/products/knowledgebase-xlr-pinout-for-etclink-and-rfu.aspx |url-status=dead |archive-url=https://web.archive.org/web/20130511023107/http://www.etcconnect.com/Community/wikis/products/knowledgebase-xlr-pinout-for-etclink-and-rfu.aspx |archive-date=11 May 2013 }}</ref>{{Unreliable source?|date=January 2012}} Another common use is professional stereo headset with balanced microphone (headphone left-pin 4, headphone right-pin 5, headphone common-pin 3, mic high-pin 2, mic low-pin 1, mic ground-pin 6).{{Citation needed|date=November 2020}}

=== Seven-pin (XLR7) ===

Seven-pin XLR connectors are used to connect some valve (tube) condenser microphones to their power supplies (carrying signal, polarisation voltage, heater and HT).<ref>{{cite web |url=http://www.sterlingaudio.net/products/index.cfm?product=STEC7&modId=0 |title=7-pin XLR Cable |publisher=Sterling Audio |access-date=2012-09-06 |url-status=dead |archive-url=https://web.archive.org/web/20120910000551/http://sterlingaudio.net/products/index.cfm?product=STEC7&modId=0 |archive-date=10 September 2012 }}</ref>

Used by several models of Le Maitre and Ultratec [[fog machines]] for remote control.{{Citation needed|date=November 2020}}

An obsolete use for seven-pin XLR connectors was analogue lighting control signals, as well as for wired intercom in broadcast studios, specifically with Ward-Beck intercoms.{{Citation needed|date=November 2020}}

=== PDN ===

The ''loudspeaker Cannon'' (known as a ''PDN'' connector) had blue or white insulation (depending on its [[Gender of connectors and fasteners|gender]]), and was intended for connections between audio [[power amplifier]]s and [[loudspeaker]]s. These are manufactured by [[Amphenol]] (formerly by Alcatel Components and ITT Cannon Australia).{{Citation needed|date=November 2020}}

==Obsolete patterns==
[[File:PICT6267a XLR-LNE PLug and Socket.jpg|thumb|XLR-LNE three-pin male and female connectors, originally used for [[mains electricity|mains]] power connections. The connecting pins in the male connector are recessed and the sockets in the female connectors are shrouded for safety. This example is a panel socket, used as a power input from the male plug, though they were also used in the opposite configuration]]

Many other types of connectors using the XLR type shell exist, with various pin configurations. One is the now obsolete three-pin power pattern connector manufactured by [[Cannon (company)|ITT Cannon]].

The ''power Cannon'' (also called the ''XLR-LNE'' connector) had shrouded pins and red insulation; it was intended as a [[mains power plug]], alternative to the [[IEC 60320]] series of connectors, but was only used on a few pieces of equipment.

===Two-pin (XLR2)===
A two-pin variant was used as the DC power input socket on Yamaha's 1970s CP-series 'Electric Grand' pianos (CP-60, CP-70 and CP-80).<ref>{{Cite web |title=Yamaha CP-70B Owner's Manual |url=https://manualzz.com/doc/1809422/yamaha-cp-70b-owner-s-manual |page=7}}</ref>

== Technical usage information ==
{{More citations needed section|date=March 2022}}
This section contains more technical information relating the most common applications of XLR connectors.

===Three-pin in audio use===
[[File:XLR3-edit.jpg|thumb|Left to right: [[Cannon (company)|Cannon]] XLR3-12C (line), [[Switchcraft]] X3F (line), [[Neutrik]] NC3MP panel, Neutrik NC3FP panel]]
[[File:XLR-phone jack combo connector.jpg|thumb|XLR and {{Fraction|1|4}}&nbsp;inch [[Phone connector (audio)|TRS phone connector]] combo jack.]]

[[Electronic Industries Alliance|EIA]] Standard RS-297-A describes the use of the three-pin XLR - known as XLR3 - for [[balanced audio]] signal level applications:
{| class="wikitable"
|-
| colspan="2" style="text-align:center;"| [[File:XLR pinouts.svg|300px]]
|-
! Pin
! Function
|-
| 1   || Chassis [[ground (electricity)|ground]] (cable shield)
|-
| 2   || Positive polarity terminal for [[balanced audio]] circuits (aka "hot")
|-
| 3   || Negative polarity terminal for balanced circuits (aka "cold")<ref>{{cite web|url=http://www.aes.org/publications/standards/search.cfm?docID=19|title=AES Standard » AES14-1992 (s2014): AES standard for professional audio equipment - Application of connectors, part 1, XLR-type polarity and gender|website=www.aes.org}}</ref>
|}

Prior to the introduction of this standard, the wiring of pins 2 and 3 varied. The pin 2 "hot" and pin 3 "cold" convention was typically used by European and Japanese equipment manufacturers, but American companies used pin 3 "hot" and pin 2 "cold". This caused problems when interconnecting equipment with unbalanced connections. The pin 3 "hot" convention is now obsolete but is still found on vintage equipment.<ref>{{cite web |url=http://www.clarkwire.com/PinOutXLRBalanced.htm |title=3-Pin XLR Audio Pinout |publisher=Clark wire and cable |access-date=2012-03-12 |archive-date=28 February 2006 |archive-url=https://web.archive.org/web/20060228061806/http://www.clarkwire.com/PinOutXLRBalanced.htm |url-status=dead }}</ref> Pin 1 has always been ground and/or shield if the cable is shielded, and many connectors connect it internally to the connector shell or case.

Although covered in industry technical standards,<ref>{{cite web|url=http://www.aes.org/publications/standards/search.cfm?docID=44|title=AES Standard » AES48-2005 (s2015): AES standard on interconnections - Grounding and EMC practices - Shields of connectors in audio equipment containing active circuitry|website=www.aes.org}}</ref><ref>[http://www.aes.org/publications/standards/search.cfm?docID=71 AES54-3-xxxx],</ref> there is still some disagreement on the best way to handle the use of pin 1 for grounding (earthing). The main controversy is whether the shell of the connector should be connected to pin 1 or the shield, or left floating. AES standards mentioned above recommend that shells of cable-mounted connectors should never be connected to pin 1 or the shield, because inadvertent contact of the shell with another grounded surface while in use can create unwanted current paths for fault current, potentially causing hum and other noise. On the other hand, equipment containing active circuitry should always have pin 1 connected to the conductive enclosure of the equipment as close as possible to the point where the signal enters the enclosure. The argument centers on the radio frequency shielding provided by the shell of the connector, which may be reduced if it is left floating. An alternative solution is to connect the shell to pin 1 and the shield through a small value capacitor, providing RF shielding but allowing very little audio-frequency current to flow. This capability can be built into a fixed jack or a cable terminated with XLR connectors.{{Citation needed|date=November 2020}}

The standard signal flow for audio in XLR connectors is that the output is a male connector and the input is female. In other words, the pins on the plug point in the direction of signal flow. [[Phantom power]], if used, originates from the socket and flows into the plug, (the opposite direction to the signal and the normal direction for power circuits). The voltages of microphone and line level audio signals are not hazardous. The male XLR is usually incorporated in the body of a [[microphone]].

Since equipment often requires an input on a TRS phone jack or an XLR connector, Neutrik and [[Amphenol]] offer several models of combination connector that accept both XLR and {{Convert|6.5|mm|in|abbr=on|adj=on|frac=4}} [[Phone connector (audio)|TS or TRS phone]] plugs.

=== Four-pin – DC power ===

The most common standard is for pin 1 to be ground and pin 4 to be 12 volts (nominal), with pins 2 and 3 unused. This configuration is used on most professional video cameras and is also common on audio equipment designed for location use.<ref name="pinouts.ru"/> There are other non-standard arrangements, particularly found on older equipment.

=== Four-pin – intercom headset ===

Clear-Com, Telex, RTS and many other production intercom systems use four-pin XLR connectors for attaching monaural intercom headsets or handsets. The standard pinout for four-pin XLR headsets is: Pin 1 = Microphone ground (screen/shield); Pin 2 = Microphone signal ("hot") input; Pin 3 = Headphone ground (return); Pin 4 = Headphone signal ("hot") output.<ref>http://www.clearcomip.com/salesforce/default.aspx?SF=/servlet/servlet.FileDownloadPkb?file=00P50000008YnrN&orgId=00D500000007yiL&pPid=50150000000aN4i {{dead link|date=February 2016}}</ref>

=== Five-pin – DMX512 and DC power for audio systems ===
[[File:XLR5 pinouts.svg|thumb|right|XLR5 pinout]]

The five-pin XLR is the standard connector for [[DMX512#Connectors|DMX512]], the most common protocol for controlling professional lighting and related equipment.<ref name="DMX512 Standard Pinouts"/> Three-pin XLR connectors are increasingly common instead. These are electrically compatible with a simple jumpering 1–1, 2–2, 3–3 between them.  However, using three-pin XLR connectors for DMX512 is specifically prohibited by section 7.1.2 of the DMX512 standard.<ref name="tsp.plasa.org"/>

Five-pin XLR is also a common power connector in modular professional audio systems, such as the [[Automated Processes, Inc.]]'s (API) Lunchbox format.<ref>{{cite web|url=http://apiaudio.com/product_specs.php?id=110|title=API 500VPR: 10 slot Rack with Power Supply|website=apiaudio.com|access-date=27 May 2016|archive-date=24 June 2016|archive-url=https://web.archive.org/web/20160624134611/http://apiaudio.com/product_specs.php?id=110|url-status=dead}}</ref> This format is becoming increasingly popular and five-pin XLR for DC power is used by many third-party module and chassis developers such as BAE Audio<ref>{{cite web|url=http://www.baeaudio.com/products/500-series-racks|title=500 Series Racks|first=British Audio|last=Engineering|website=baeaudio.com}}</ref> and JLM Audio.<ref>{{cite web|url=http://www.jlmaudio.com/shop/16v-2a-48v-120ma-65w-smps.html|title=JLM Audio Shop|website=www.jlmaudio.com}}</ref> It is also used by Slate Digital for the VMS1 microphone preamp.<ref>{{Cite web |title=Virtual Microphone System User Guide |url=http://download.slatedigital.com/vmr/Virtual%20Microphone%20System%20-%20User%20Guide.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160606105055/http://download.slatedigital.com/vmr/Virtual%20Microphone%20System%20-%20User%20Guide.pdf |archive-date=6 June 2016 |access-date=27 May 2016}}</ref> Typically the pin configuration is:

* Pin 1: Chassis Ground
* Pin 2: Power Ground
* Pin 3: Positive Voltage (Typically +15 volts or +16 volts)
* Pin 4: Negative Voltage (Typically -15 volts or -16 volts)
* Pin 5: Phantom Power Voltage (Typically +48 volts)

Where XLR connectors are used for DC power, the genders are reversed with respect to their standard use for line-level and mic-level audio. Typically, audio signals on XLR connectors "follow the pin," such that a male connector is an output and a female connector is an input. In most power applications (not just XLR connectors) the female connector is the output and the male connector is the input. This makes accidental contact with live parts less likely. In audio devices it also prevents accidental application of DC power to signal inputs.

== Other uses ==

Three-pin XLR connectors were once used extensively on loudspeaker cables, because when first introduced they represented a new standard of ruggedness, and economical alternatives were not readily available. Often, two-conductor loudspeaker cable had three-pin female connectors on both ends, to distinguish it from a three-conductor shielded signal-level cable, which has a female connector at one end and a male at the other. Either pin 2 or 3 was live, depending on the manufacturer, with pin 1 always the 'earth' return. This use has become  both obsolete and dangerous to equipment but is still sometimes encountered on older equipment. For example, some loudspeakers have a built-in male connector as an ''input'' connector for speaker-level signal. This has been superseded in professional audio applications by the Neutrik [[Speakon connector]].

Three pin XLR connectors are popular power connectors for charging [[ebike]] batteries (24V, 36v and 48v).<ref>{{Cite web |last=Hicks |first=Eric |date=2015-04-17 |title=Definitive Guide to Ebike Connectors |url=https://www.electricbike.com/ebike-connectors/ |access-date=2024-03-31 |website=ElectricBike.com |language=en-US}}</ref>

<gallery>
Image:XLR4_PICT6913a.jpg|Male and female XLR4 panel connectors
Image:XLR5_PICT6952a.jpg|Female XLR5 panel connector
Image:XLR6_PICT6912a.jpg|Female XLR6 panel connector
</gallery>

== Phantom power ==
{{main|Phantom power}}

Some microphones such as [[condenser microphone]]s require power. An alternative to battery power is phantom power, which consists of direct current applied equally through the two [[signal]] lines of a [[balanced audio connector]], usually a three-pin XLR connector. The supply voltage is referenced to the ground pin of the connector (pin 1 of an XLR), which normally is connected to the cable shield or a ground wire in the cable or both. Phantom power is usually supplied at a nominal 48 volts DC, although lower voltages are permissible and modern microphones will often operate over a wide range.

It is common for modern mixers to have a built-in switch-operated 48-volt power supply which supplies individual or all mic inputs with phantom power, thus eliminating the need for bulky external supplies on individual mics.

==XLD keyed variant==
The '''XLD connector''' is a proposed keyed variant of the XLR connector. The keys prevent accidental mixing of XLR and XLD connectors. XLD plugs and sockets are used mostly in [[Sound recording and reproduction|professional audio]] and video electronics cabling applications.

The XLD connector is proposed by the [[Audio Engineering Society]] AES42 [[Microphone#Digital microphone interface|digital microphone interface]] standard.

The connectors are similar to XLR but with an extra coding key and groove that allows control over the intermating of XLD plugs and XLR sockets. A connector with the coding key installed will not mate with a connector that does not have the matching groove.<ref>Don Davis, Eugene Patronis
''Sound system engineering Third edition'', Focal Press, 2006  {{ISBN|0-240-80830-4}}, page 448</ref> By suitably keying connectors, analog microphones can be protected from damage by the high current digital phantom power supply provided for digital microphones.

== Mini connectors ==
[[File:XLR and Mini XLR.jpg|thumb|XLR and Mini XLR connectors]]

The ''Mini-XLR''<ref name=":0">{{Cite web |title=Sealed Tini-QG Mini-XLR Connectors |url=https://www.switchcraft.com/sealed-tini-qg-mini-xlr-connectors/ |access-date=2025-11-14 |website=Switchcraft}}</ref> or ''Tiny XLR''<ref name=":1">{{Cite web |last=Rean |title=Tiny XLR |url=https://www.rean-connectors.com/en/rean/products/indoor/xlr-connectors/tiny-xlr |access-date=2025-11-14 |website=Rean |language=en}}</ref> connector, also known as the "Tini-QG"<ref name=":0" /> or "TQG",<ref>{{Cite web |title=EH TQG Panel Connector, 3 Contacts, Female, Black Finish, Silver Contact Plating |url=https://www.switchcraft.com/eh-tqg-panel-connector-3-contacts-female-black-finish-silver-contact-plating/eht3fb/ |access-date=2025-11-14 |website=Switchcraft}}</ref> is used on compact items such as UHF wireless microphone beltpacks, some studio and field recording headphones, as well as [[Audio Technica]] condenser microphones, but is not in general use on major items such as mixing desks. The Mini XLR Connector was first devised by Switchcraft<ref>{{Cite web |url=https://www.switchcraft.com/Specification.aspx|archiveurl=https://web.archive.org/web/20141027150424/http://www.switchcraft.com/Specification.aspx|url-status=dead|title=Switchcraft : Specification|archivedate=27 October 2014|website=www.switchcraft.com}}</ref> and is also available from Rean,<ref name=":1" /> and various other sources. As yet,{{When|date=November 2020}} the Mini XLR connectors do not appear to be covered by any ISO or national standard.{{Citation needed|date=November 2020}}

Part numbers vary by manufacturer, number of pins, and mounting method.  Switchcraft uses TA3''x'', TA4''x'', etc.<ref>{{cite web |title=Shure catalog page (archived) |url=http://www.shure.com/americas/products/accessories/wireless-systems/wireless-systems-cables-connectors |url-status=dead |archive-url=https://web.archive.org/web/20160206103225/http://www.shure.com/americas/products/accessories/wireless-systems/wireless-systems-cables-connectors |archive-date=6 February 2016 |access-date=6 February 2016}}</ref> for inline connectors, and TB3''x'', TB4''x'', etc. for panel-mount connectors,<ref name=":0" /> while Rean uses RT3''x'', RT4''x'', etc.<ref name=":1" />

== See also ==
{{Portal|Electronics}}
* [[Phone connector (audio)]]
* [[RCA connector]]
* [[RF connector]]

== Notes ==
{{Notelist-lr}}

== References ==
{{Commons category|XLR connectors}}
{{reflist}}

{{AVconn}}
{{Audio and video interfaces and connectors}}

[[Category:Audiovisual connectors]]
[[Category:DC power connectors]]
[[Category:Electrical signal connectors]]
[[Category:American inventions]]