What is XLR Jack?

XLR jack is a socket for the male XLR connector, which is commonly found on audio, video, and lighting equipment. When the male and female are connected, they usually carry electrical, balanced audio interconnection. Unlike most connectors, XLR’s development was incremental. Cannon came up with the first version of the connector, which was called Cannon X. The connector, however, easily gets loose, disrupting the signal flow. In 1950, a latch was added to the assembly to mitigate this problem forming the XL part of the connector. In 1955, synthetic rubber insulation was added to coat the contact pins of the female connector, finally forming the XLR connector.


XLR jack is a circular jack with a varying number of holes that caters to the number of pins of the XLR connector. The original connector had three contact pins, one for the ground, one for the positive signal, and one for the negative signal. This is still commonly used today and is commonly seen in on-stage microphones. The XLR has significantly evolved over the years, finding its way in many other applications. Some of these applications require additional contact pins. Today, the XLR connector’s pins vary from two to ten.

One thing consistent in XLR connector variants is the ground design. The ground is built to be longer than the rest of the pins so that it makes the first contact when inserted and the last one to lose contact once removed from the XLR jack. This design effectively prevents external signals from being picked up by the connector, removing undesirable audio artifacts and noise when the equipment is connected and disconnected. High-quality and more reliable XLR connectors also use Nickel-silver plating or Rhodium-coated gold for the connectors and contacts to block EMI and RF interference.

XLR connectors from different manufacturers are interoperable except for the six-pin variant. Manufacturers Swichcraft and Neutrik have different patterns for the six-pin connector causing the incompatibility for some of these connector types.

There are also XLR connectors that are built for harsh environments. These connectors are made of robust materials to withstand extreme environmental conditions. Some manufacturers also obtain an IP rating for the rugged XLR connectors to show that they can block foreign objects such as dirt, dust, and water from penetrating the cable.

Variants and Uses

Different types of XLR connectors are used in different applications. XLR is mostly used in audio equipment like microphones, equalizers, and amplifiers, but some varieties are also used in video, lighting control, and power supply applications. The connectors are designated by their number of pins. Below are the common XLR connectors and their uses.

XLR3. The three-pin connector is the most common type and has become an industry standard for balanced audio signals. This type is usually found on microphones, but it is also used in interconnect-powered speakers used in PA system applications. Other common uses of XLR3 are in mixer and amplifier inputs, and audio extension leads.

XLR4. The four-pin XLR connector finds its niche in intercom headsets where two pins are used for mono headphones, and the other two pins carry the unbalanced microphone signal. It is also used on microphones with an LED indicator where the fourth pin is used to power up the LED when the microphone is on. This type is also used in DC power connections for film and video cameras.

XLR5. This is the standard connector used in the DMX512 digital lighting control system, primarily used in linking controllers, dimmers, special lighting effects, and many other applications. The five-pin connector is also used in stereo microphones, stereo intercom headsets, and for DC power in audio equipment.

XLR6. This connector is often found in dual channel intercom systems, stage lighting control equipment, and a professional stereo headset with a balanced microphone.

Mini XLR. The smaller version of the XLR connector typically has three pins only, although a four-pin variety also exists like the TA4 connector. Aside from the smaller size, the Mini XLR is also shorter and cheaper than the standard-sized XLR connector. There are also many uses of the smaller connector. A common application is on hand-held microphones, wireless microphones, and those connected to computers. Because of its smaller size and shorter length, the Mini XLR is ideal for short distances.

XLR Adapters

XLR adapters are available to make male-to-male, female-to-female, or male-to-female XLR connections possible. There are also XLR adapters to facilitate mono and stereo connections and RCA connections, and XLR to standard jack connections such as those found on musical instruments like guitars.

Choosing an XLR Connector

XLR connectors are used in a wide variety of applications such as audio, lighting, video, and power module applications. When choosing an XLR cable and adapters, it is best to consider the cost, quality, length, and size of the connectors.

Higher-cost cables are expected of higher quality, reliability, durability and are recommended for professional use. There are also budget-friendly XLR cables that are of lower quality but are likely suitable for non-commercial use.

Quality is another important factor in choosing an XLR cable. Good quality cables are made of high-quality materials and last longer than ordinary cables. They also have higher reliability but come with a higher price tag. As with cost, you can choose a mid-range XLR cable depending on the environment where the cable will be used.

Length, size, and type are important factors to consider when buying an XLR connector. Make sure that the number and the pattern of pins match that of the jack. The length should also be long enough to connect the two devices. Lastly, the size should also be correct as there are standard-sized and miniature sizes of the connector.


The XLR connector is probably one of the long-withstanding connector types which have been around since the 1950’s. It has since expanded its application in the audio space and in the video, lighting, and power supply. There’s a wide variety of XLR connectors and jacks with various pins depending on their use. Mini XLR is also available for smaller equipment and shorter connections. XLR adapters are also around for compatibility among the different connection types.

Depending on where it will be used, consider the XLR connector’s cost and quality before purchasing one. For professional use, choose the more expensive but higher-quality connectors; otherwise, you can buy the more affordable type. If the connector is exposed to extreme environments, choose the cables with a higher IP rating.

About the author

Glynis Navarrete

A freelance blogger who loves to write about anything related to technology. Born and raised in the Philippines and worked in Singapore for eight years as Technical Support for a wide range of IT equipment. Took a dive into the world of freelancing and now enjoying doing what I’m passionate about while not losing touch with technology.