Cable Glossary: Common Connections in Your Studio
In the world of multichannel audio, connectivity has always been one of those subjects that’s too dull to spend much time talking about, but too important to ignore. Everyone has found themselves in the unenviable position of having the wrong “gozouta” for their “gozinta,” and Murphy’s Law dictates that your drawer full of adapters will contain six of everything but the one you need, including at least one that’s maddeningly close.
As more and more technology becomes wireless, the jungle of cable linguini in our studios is becoming a bit more manageable. At the same time, there’s still no shortage of cable and connector protocols to mix, match, and keep track of.
So here’s a short – and by no means complete – rundown of some of the current array of connectors in use today. In the interests of space, we’re leaving aside most of the older, lesser-used protocols like TDIF and SCSI in favor of technologies currently in use.
TRS/TS (audio)
1/4” TRS stereo cable.
Originally invented for manual telephone switchboards, the standard 1/4-inch plug has been around since the late 1800s and is still the most common type of connectors for musicians. The TRS acronym stands for “Tip-Ring-Sleeve,” representing the three parts of the connector (Tip = positive, Ring = negative, and Sleeve = ground) and carries a balanced signal. Balanced signals are needed for longer runs of cable, as unbalanced signals can create noise over long distances.
The TS (Tip-Sleeve) version is a two-wire, unbalanced version. Due to their similar appearance and physical compatibility, it’s easy to confuse a TRS connector with a two-conductor unbalanced quarter-inch plug — and if you’re only hearing one side of your stereo field, chances are that’s exactly what you’ve done.
Standard quarter-inch TS plugs are most commonly used for guitar and other electrical instrument cables. The stereo versions are common on headphones, insert cables, and inputs and outputs on audio equipment that don’t need long runs of cable to connect — like studio mixers, compressors, and preamps.
1/4” TS mono cable.
If you’ve spent any time in a traditional recording studio, you’ve likely seen another variation of the TRS plug. The pro audio and telecommunications industries have long used TT (tiny telephone) connectors in patch bays. Slightly smaller than a standard quarter-inch connector, TT patch bays have been fairly ubiquitous in the racks and consoles of recording studios, their size allowing up to 96 jacks to fit into a standard 19-inch space.
In the past decade or so, smaller variations of the TRS/TS connector have become increasingly popular, including the miniature (eighth-inch) and subminiature (3/32-inch) versions now used by most phones and MP3 players.
XLR (audio, digital audio)
Male and female XLR cables.
Introduced by Cannon Electric (now part of ITT), XLR is sometimes still referred to as a cannon connector, or colloquially as “Extra Long Run,” referring to the extra long cables that can be used with this balanced connection.
The connectors are circular, with anywhere from three to seven pins. Most commonly, the balanced three-wire version has been the de facto standard for microphones for many years. Three-pin XLRs are also used for loudspeaker connections, low-voltage power supplies, lighting controllers, and a host of other applications. They also carry digital audio signals through the professional-grade AES/EBU protocol.
Unlike an analog XLR microphone cable, AES/EBU digital connections run two channels of digital audio over a single cable. Depending on the gear, common sample rates between 44.1kHz and 96kHz can usually run through this standard “Single Wire” mode. However, “Dual Wire” mode is sometimes needed in order to run at higher sample rates for ultra high-fidelity audio, such as 176.4kHz or 192kHz. This is where only one channel of audio can run over a single XLR cable.
Other variations of XLR connectors include four-pin versions, which are used as the standard for 12-volt power in the broadcast, film, and television industries. Five-pin XLR connectors are used for some stereo microphones, like the Shure VP88. Six-pin versions are used for some stage lighting applications and intercom systems, while seven-pin models are sometimes found on older condenser microphones which use their own power supplies (as opposed to phantom power).
RCA (audio)
RCA left and right channel audio cables.
Sometimes referred to as phono or cinch connectors RCA is a two-conductor, unbalanced protocol commonly found on “prosumer” gear, as well as on turntables and consumer electronics. The RCA name comes from the electronics giant Radio Corporation of America (now a part of BMG), who introduced the design in the 1940s.
RCA connectors can also carry digital audio signals using the S/PDIF (Sony/Philips Digital Interconnect Format) protocol. They are also found on a wide range of computer audio interfaces and video equipment. Unlike an analog RCA cable, S/PDIF digital connections typically run two channels of audio over a single cable.
MIDI (data)
DIN-style connectors, used for MIDI protocol.
MIDI (Musical Instrument Digital Interface) cables have been used since the mid-1980s to interconnect computers, sequencers, keyboards, drum modules, effects boxes, and other devices, controlling them via MIDI data commands. MIDI connections also carry MTC (MIDI Time Code), which is used to synchronize DAWs, sequencers, instruments, and other MIDI-equipped devices.
These DIN-style connectors come in a variety of formats and pin configurations, but the five-pin MIDI variety is probably what you’re most accustomed to seeing. Unlike the other connectors we’ve talked about thus far, MIDI cables are strictly for data.
ADAT Lightpipe (digital audio)
ADAT Lightpipe cables.
ADAT Lightpipe began on the Alesis ADAT digital multitrack tape machines introduced in 1992. Lightpipe carries eight channels of uncompressed 24-bit digital audio (at a 44.1 kHz or 48 kHz sample rate) over a fiber optic cable, and was originally used to transfer audio between ADAT recorders. While the ADAT recorder itself has found its way into the history books, its Lightpipe format has become a ubiquitous standard, used in digital mixing consoles, converters, audio interfaces, effects devices, and more.
In recent years, more engineers are preferring to track and mix at higher sample rates for ultra-high fidelity audio production. To allow higher sample rates of digital audio to pass through Lightpipe, “Sample Multiplexing” support, or S/MUX, was conceived. While ADAT Lightpipe typically allows for eight channels of digital audio to pass through at 44.1 kHz or 48kHz, S/MUX enables four channels of digital audio to pass through at 88.2 or 96 kHz, or two channels of digital audio at 176.4 or 192 kHz.
S/MUX technology over Lightpipe is why you may often see four ADAT ports on a lot of current gear — two for input, two for output. However, not all audio equipment with ADAT Lightpipe ports support S/MUX, so it’s important (as always!) to check the manual.
Word Clock
BNC cables, for Word Clock.
The BNC (British Naval Connection) coaxial protocol is used in the studio to carry Word Clock, a signal used to synchronize DAWs, digital tape machines, and other devices connecting via S/PDIF, AES/EBU, ADAT, or other digital audio formats.
USB (audio, data, connectivity)
USB 3.0 can carry up to 5 Gigabits of data per second.
Universal Serial Bus has become an industry standard since its introduction in the late 1990s. It was designed as a connectivity protocol for computers, and is used today for everything from keyboards, printers, smartphones, and hard drives, to audio interfaces, MIDI interfaces, and other audio devices. It’s rare these days to find a computer or device that is not equipped with at least one USB port.
The original USB 1.0 spec only supported a maximum data throughput rate of 12 Mbps (megabits per second), making it impractical for carrying more than four channels of audio. The introduction of USB 2.0 in 2000, with a throughput of 480 Mbps, upped the ante considerably, opening the floodgates for multi-channel USB devices. In late 2008 the USB 3.0 spec was released, capable of up to 5 Gbps (gigabits per second) throughput, breathing new life into the USB protocol.
FireWire (audio, data, connectivity)
FireWire 400 and 800 cables.
FireWire is the trade name created by Apple for the IEEE 1394 high-speed serial bus protocol. Introduced on Apple computers around 1999 (and on some Sony computers as i.Link), FireWire is a contender with USB for video and multichannel audio communication, as well as for hard disks and other computer peripherals.
6-pin FireWire 400 connections can be found on a majority of audio interfaces made over the last decade. A 4-pin FireWire 400 connection used to be common on Windows-based operating systems, but now are not as prevalent.
Today, the most commonly found Firewire connection on modern Macs and the latest FireWire audio interfaces is a 9-pin FireWire 800 connection. The biggest differences between FireWire 400 and 800 is the amount of data throughput. FireWire 400 supports 400 Mbps, while FireWire 800 supports 800 Mbps. So, you can run more channels of audio on FireWire 800.
Thunderbolt (audio, data, connectivity)
Thunderbolt is ideal for high bandwidth audio, and
connecting for multiple bandwidth-hungry devices.
Developed by Intel with collaboration from Apple, Thunderbolt is the latest high-speed cable protocol for connecting computer peripherals such audio interfaces, hard drives, display monitors, video equipment, and more.
Thunderbolt has a unique flexibility because it can run multiple formats, simultaneously, over a single Thunderbolt cable. At its core, Thunderbolt supports native PCI Express (PCIe) and Apple DisplayPort protocols, but can be adapted to just about any protocol that would typically run on a PCIe card — FireWire, USB, HDMI, Ethernet, you name it. However, with Thunderbolt, you don’t need any PCIe slots, just a Thunderbolt port on your Mac or PC.
Though it’s still early days for Thunderbolt, many computer manufacturers are embracing the technology, and many new computers will be sporting Thunderbolt ports in the coming years.
— Daniel Keller
Thankfully, hooking up audio and AV systems is much more straightforward than it used to be. For most people, home entertainment systems no longer consist of large racks of individual components hiding a rat’s nest of wires and connectors, and we’re better off for it. But there are still times you need to connect audio hardware devices, and if you need to source cables (cords), connectors, or adapters, knowing the specific names of each type is necessary. Let’s go over the ones you’re most likely to encounter.
Editor’s note: This post was updated on July 7, 2023, to account for changes in 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 a jack plug. Suppose they’re standard stereo headphones with no microphone. In that case, it’s a three-terminal tip-ring-sleeve (TRS) connector, easily identified by the two insulating bands (usually black) on the barrel of the jack. These are commonly found in two sizes. The smaller size found on portable devices is referred to as a minijack, or by its diameter, 3.5mm. It’s sometimes called 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.
This earphone’s cable terminates into a 90-degree TRRS jack.
Wired headphones with a microphone built-in use a modified version of the same-sized 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, which has three insulating bands visible on the barrel.
How do I connect my headphones when there’s no jack socket?
These end in a 3.5mm connector, so you’ll need to use a stupid dongle on new phones.
Since smartphones have 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 to plug in your headphones. 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 a set of wired USB headphones to plug directly into your phone. If you prefer to avoid dealing 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 come wired with a four-pin XLR for differential drive.
You may have run into premium headphones with other jack sizes, different pin configurations (4.4mm Pentaconn), or larger XLR-type connectors. These are required to run your headphones in a balanced or differential drive configuration.
What connectors are used at the headphone end of the cable?
The cable plugs into the bottom of each ear cup via 2.5mm jacks.
When the cable is removable, the plugs used at the headphone end vary quite a bit, and we won’t cover them all here. 3.5mm jacks with a twist-to-lock system are relatively 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; some use propriety connectors like Sennheiser‘s two-pin push-fit connector.
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 fit into a pair of in-ear monitors easily. These are used mainly for better-engineered in-ear monitors, where having a replaceable cable means the headset doesn’t become 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 to connect audio signals at “line level” in several contexts. 3.5mm TRS minijacks are found at the ends of the standard auxiliary (“aux”) cable to connect your phone directly to a portable speaker or car stereo system. The larger 1/4-inch plugs are used in semi-professional applications to connect signals using TS plugs (unbalanced applications) or TRS plugs (balanced applications).
What are XLR connectors?
XLR cables are used for microphones and other pro audio applications.
XLR connectors carry the tiny electrical signals produced by microphones and in other instances where signal integrity is essential — typically professional audio environments. Microphones have male outputs, and mic preamps have female input connectors on the front; hence, the standard XLR cable has a female on one end and a male on the other. The locking connectors are relatively large and heavy, explicitly designed for carrying balanced signals and wired using balanced (microphone) cable. This cable type is well suited to longer cable runs, as they have better shielding and noise rejection abilities.
What are RCA connectors?
RCA-type plugs are usually color-coded red (right) and white (left) for stereo interconnection.
RCA (or phono) connectors are smaller cinch-type connectors used in interconnects 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 older hifi system components or 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 suitable for relatively short-distance transmission of audio and video signals. They are still reasonably common, particularly for connecting record player turntables to phono input stages or 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?
Speaker wire comes in different gauges and can be terminated with bare connections or connectors like these gold-plated banana plugs.
Unless you’re hooking up a PA system, the primary connector you’ll likely need to connect 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, connecting the positive terminal at the source (amplifier) to the corresponding terminal on your speaker is essential 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 uses RCA (phono) connectors, as shown below.
Active loudspeakers have built-in amplifiers and require a power source.
How is speaker wire different from regular stereo wire?
Stereo interconnects, which usually have red and white (or red and black) labeled RCA connectors on the ends, are intended for low audio 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 required 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 in spending a lot of money on cables, as this past experiment demonstrates.
How are digital connections different from analog ones?
Digital audio connections transfer signals between devices without converting 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?
HDMI cables carry up to 32 channels of digital audio.
Standard consumer-level wired stereo digital connections, often labeled “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 audio channels (for HDMI version 2 and above) for surround systems, including Dolby ATMOS, and offer bidirectional capabilities in the form of HDMI ARC and eARC.
What are optical connections for?
An optical cable can transmit stereo digital audio signals.
Optical cables (also called TOSLINK) carry digital audio between devices in much the same way as a wired coax connection, 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 also carry up to eight audio channels in multichannel applications.
If you’re looking to transfer audio between devices, these are the most common ways, depending on 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.