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A guide to audio connectors and cable types

Get to know all the ways to connect with your music
By
December 29, 2022
An audio mixer with an assortment of connected wires and adaptors.

Hooking up audio and AV systems is (thankfully) a lot more straightforward than it used to be. For most people, home entertainment systems no longer consist of large racks of individual components hiding a rats nest of wires and connectors, and we’re better off for it. But there are still times you need to connect your audio hardware devices together, and if you need to source cables (cords), connectors, or adapters, knowing the specific names of each type is absolutely necessary. Let’s go over the ones you’re most likely to encounter.

Editor’s note: This post was rewritten and expanded on December 29, 2022 to account for changes in technology and the market, as well as changes to our house style and formatting standards.

How do I connect my headphones?

The two most common sizes of TRS jack connectors.

Wired headphones connect to a playback device’s analog headphone socket using what’s called a jack plug. If they’re standard stereo headphones with no microphone, it’s a three-terminal tip-ring-sleeve (TRS) connector in one of two sizes. The smaller size found on portable devices is referred to as a minijack, or by its diameter, 3.5mm. It’s sometime referred to as a 1/8 inch jack in the US, though that’s an approximation. The larger size of headphone jack you’ll find is commonly known as a 1/4 inch (or 6.3mm) jack plug. Adapters are easy to find to change one size jack plug to the other.

An aerial view of the earphones and the headphone jack.
This earphones’ cable terminates into a 90-degree TRRS jack.

Wired headphones with a microphone built in use a modified version of the same size minijack plug, but with an additional electrical terminal (to carry the mic signal) in the form of an extra ring, making it a tip-ring-ring-sleeve (TRRS) connector.

How do I connect my headphones when there’s no jack socket?

The 1More Triple Driver In-Ear earbuds plugged into the dongle.
These end in a 3.5mm connector, so you’ll need to use a stupid dongle on new phones.

Since smartphones have largely abandoned the headphone jack, you have three options. If you already have wired headphones you want to use, you’ll need a special adapter (a dongle) to connect to the phone’s system connector (a Lightning connector on iPhones, or USB-C for basically everything else) and provide you with the analog 3.5mm headphone socket you need. These are also referred to as digital-to-analog converters (DACs).

If you want to stick with wired (for reasons) and don’t want to deal with dongles, you can get yourself a set of wired, USB headphones to plug directly into your phone. If you would prefer not to deal with dongles or wires, you can also go down the wireless Bluetooth route.

What are the other types of headphone connectors called?

The Drop+Ether CX closed-back headphones with a focus on their 4 pin XLR for differential drive.
The Drop+Ether CX closed-back headphones come wired with a 4 pin XLR for differential drive.

You may have run into premium headphones with other sizes of jack, with different pin configurations (4.4mm Pentacon), or the much larger external line return (XLR) type connectors. These are required if you wish to run your headphones in a balanced, or differential drive configuration.

What connectors are used at the headphone end of the cable?

Plugging in the 2.5mm jack into the bottom of the right ear cup.
The cable plugs into the bottom of each ear cup via 2.5mm jacks.

Where the cable is removable, the plugs used at the headphone end of the cable vary quite a bit and we won’t cover them all here. 3.5mm jacks with a twist to lock system are fairly common. You’ll also find 2.5mm TRS jack plugs on some headphones (Bose for example), while others have 2.5mm TS jack inputs at the bottom of each ear cup for the wires to connect to (the Monoprice Monolith M1060 for example). Premium headphones can use mini XLR connectors, and some use propriety connectors like Sennheiser‘s two-pin push fit connector.

Shure BT2: Overhead image of the RMCE connectors at the end of the cables with the detached SE215 earbuds shown, too.
The MMCX connectors are gold-plated and fit snugly into the SE215 female input.

Many in-ear monitor (IEM) headphones employ micro-miniature coaxial (MMCX) connectors. As the name implies, this connection standard is small enough to easily fit into a pair of in-ear monitors. This attachment is used mainly for better engineered in-ear monitors, where having a replaceable cable means the headset isn’t trash if the cable fails. Plus, the connection itself locks into place and allows for 360 degrees of rotation, so not only does it make the cable easier to replace, but it also makes it harder to break in the first place.

What else are jack plugs used for?

Jack plugs are also used for connecting audio signals  at “line level” in a few different contexts. 3.5mm TRS minijacks are found at the ends of the common auxiliary (“aux”) cable used to connect your phone directly to a portable speaker or car stereo system, for example. The larger 1/4 inch plugs are used in semi professional applications to connect signals either using TS plugs (for unbalanced applications) or TRS plugs (for balanced applications). You can read more about what this means here.

What are XLR connectors?

Close-up shot of the pins in an XLR cable and on a microphone and audio interface
XLR cables are used for microphones and other pro audio applications.

XLR connectors are used to carry the small signals produced by microphones, and in other instances where signal integrity is important — typically professional audio environments. Microphones have male outputs, and mic preamps have female input connectors on the front, and hence the standard XLR cable has a female on one end and a male on the other. The plugs themselves are relatively large and heavy, designed specifically for carrying balanced signals, wired using balanced (microphone) cable. This type of cable is well suited to longer cable runs, as they have better shielding and noise rejection abilities.

What are RCA connectors?

Red and White RCA Phono Cinch connectors shown alongside a 3.5mm minijack plug.
RCA type plugs are usually color coded red (right) and white (left) for stereo interconnection.

RCA (or phono) connectors are smaller cinch type connectors, often used for connecting “line level” audio signals in consumer products. You’ll likely recognize the red and white color-coded stereo cables from their use in connecting together older hifi system components, or alternatively the yellow plugs that carry analog video signals to TVs from old DVD players, VCRs, or video game consoles. Since they can only carry unbalanced signals, they’re only good for relatively short-distance transmission of audio and video signals. They are still fairly common, particularly for connecting record player turntables to phono input stages, or for connecting home theater subwoofers. They are also used for coaxial, digital audio connections (see the section later on).

Unlike a lot of connectors, the RCA name isn’t derived from a particular physical aspect of the connection. It’s named after the Radio Corporation of America, which developed and introduced the standard in the 1930s.

What connectors are used for speaker cables?

3 speaker cables showing bare end terminations, as well gold plated banana plugs.
Speaker wire comes in different gauges, and can be terminated with bare connections or connectors like the gold plated banana plugs shown here.

Unless you’re hooking up a PA system, the primary connector you’re likely to need when connecting up your speakers is the banana plug, shown above on the right. Many speakers have binding posts or terminal clamps that will accept the bare ends of the speaker wire. If that’s the case, it’s important to make sure you connect the positive terminal at the source (amplifier) to the corresponding terminal on your speaker to keep everything in phase. Most speaker wire has an identifying mark on one of the conductors to help you keep track of what’s what.  In some smaller powered speaker systems, the cable that connects the left and right speakers together uses RCA (phono) connectors, as shown below.

A pair of active speakers, made by Creative, viewed from the back.
Active loudspeakers have built in amplifiers, and require a power source.

How is speaker wire different from regular stereo wire?

Stereo interconnects, which are usually red and white (or red and black) have RCA connectors on the ends, and are intended for low voltages (line level) with low current, and have a central insulated conductor surrounded by a shield (ground) for each channel (left and right).

Speaker cable, or speaker wire, consists of a pair of conductors surrounded by an insulating, flexible PVC or similar material that either has bare ends or banana plugs (see above) at the end. This cable should be specified to carry the power needed to drive loudspeakers to produce sound. Heavier gauge wire is needed for higher power, and cables should always be kept as short as possible. As long as these basic requirements are met, there’s no point spending a lot of money on cables, as our past experiment demonstrates.

How are digital connections different from analog ones?

Digital audio connections transfer signals between devices without having to convert them to analog and back again, which means the quality is preserved. Another bonus is that digital signals are less susceptible to sources of noise and interference, which makes cable quality even less of a concern than with analog.

What type of wire do I need for a digital audio connection?

A row of HDMI input sockets on the back of a TV, one of which is labelled HDMI eARC. A cable is being plugged into this one.
Austin Kwok / SoundGuys
HDMI cables carry up to 32 channels of digital audio.

Standard consumer-level wired stereo digital connections, often labelled “coax”(pronounced co-axe, not like the word coax) use the same RCA connectors we discussed previously, specifically with 75ohm coaxial cable. Home theater and AV systems are more likely to use high-definition multimedia interface (HDMI) cables , which also carry digital video signals. These allow eight or 32 channels of audio (for HDMI version 2 and above) for surround systems, including Dolby ATMOS, and also offer bidirectional capabilities in the form of HDMI ARC and eARC. There’s a full explainer here.

What are optical connections for?

Both ends of an optical cable.
An optical cable can transmit stereo digital audio signals.

Optical cables (also called TOSLINK) are used for carrying digital audio between devices in much the same way as a wired coax connection, but using light to represent the binary data instead of electrical voltage levels. These are preferred in most applications for stereo as they provide electrical isolation between devices, and they can carry up to eight channels of audio in multichannel applications.

If you’re looking to transfer audio between devices, these are the most common ways to do it. The biggest differences come down to the type and age of equipment you’re looking to connect. Hopefully, this has helped, and now whether you’re looking to listen to music wirelessly, or hook up a state of the art soundbar, you’ll know what you need to do it.