Audio Connectors and Cable Types: What Each One Is For

The easiest way to choose an audio cable is to match the signal type first, not the marketing. Use XLR or 1/4-inch TRS for balanced mono and longer pro-style runs, TS for guitars and other unbalanced mono connections, RCA for home stereo line-level gear, optical or digital coax for older digital audio links, and HDMI with eARC when a TV and soundbar or AV receiver support it.

Table Of Contents

Quick connector map

Connector or cable	Signal type	Most common use	Best when
TS 1/4-inch	Analog, usually unbalanced mono	Guitars, short instrument runs	You need a simple mono instrument connection.
TRS 1/4-inch	Analog, stereo or balanced mono	Headphones, mixers, interfaces	You need stereo headphones or a balanced line.
3.5 mm TRS	Analog, usually stereo	Portable gear, laptops, small audio devices	Your device has the smaller headphone-style jack.
XLR	Analog, balanced	Microphones, mixers, active speakers	You need secure pro-audio connections or longer runs.
RCA	Analog, usually unbalanced	Home stereo and legacy AV gear	You are connecting consumer line-level equipment.
Optical or digital coax	Digital audio	TVs, DVD players, AV receivers, soundbars	You need digital audio but not HDMI-based control features.
HDMI with ARC or eARC	Digital audio and video	TV to soundbar or AV receiver	You want one cable plus the broadest modern TV-audio feature set.

Balanced vs unbalanced

This is the first split that matters. Neutrik's Plugs and Jacks FAQ says 2-pole tip-sleeve plugs are commonly used with unbalanced mono signals, while 3-pole tip-ring-sleeve connectors can carry stereo or balanced mono. Its XLR FAQ shows the same balanced idea on XLR: ground on pin 1, hot on pin 2, and cold on pin 3.

TS and TRS cables

TS and TRS look similar, but they are not interchangeable by default. Neutrik says TS is the usual choice for short unbalanced runs such as guitar cables, while TRS is used for stereo headphones or balanced mono line connections. Neutrik also notes that plugging an unbalanced TS path into a balanced line can leave you with only half the expected signal voltage.

3.5 mm vs 6.3 mm jacks

The small and large headphone-style plugs usually follow the same electrical idea. Neutrik's 3.5 mm audio plug documentation identifies a 3-pole 3.5 mm plug, while its 1/4-inch plug line covers 2-pole and 3-pole 6.3 mm plugs. In practice, the difference is usually device class and durability, not magic sound quality.

XLR cables

XLR remains the default pro-audio connector for microphones and many balanced line connections. Neutrik's XLR FAQ says XLR is used mostly in professional audio and video cabling, including microphones, studio gear, active loudspeakers, and some lighting applications. If you are wiring mics, mixers, or active PA gear, XLR is usually the first connector to check for.

RCA and digital coaxial

RCA is still common on consumer AV gear, but it is usually an unbalanced analog connector. Neutrik's Phono or RCA FAQ places RCA in typical hi-fi and TV applications. Sony's optical-vs-coax explanation adds an important distinction: a digital coaxial audio link also uses RCA-type connectors, but it is a different digital-audio connection, not the same thing as the red and white analog pair.

Optical digital cables

Sony says a digital optical connection carries the audio bitstream through a fiber-optic cable using pulses of light. That makes optical useful when your TV, receiver, or soundbar has matching optical ports but no better HDMI audio path. The tradeoff is practical rather than theoretical: Sony's current soundbar connection guide says an optical-only setup will not support some HDMI-only conveniences such as power interlock and TV-remote volume control.

HDMI and eARC

For most TV-audio setups, HDMI is the cleanest modern answer because it can carry audio and control features on one cable. HDMI Licensing Administrator says the latest public spec family is HDMI 2.2, and its eARC overview says eARC supports high-bitrate and multichannel formats while simplifying TV-to-audio-system connectivity. If your TV and soundbar or receiver both have ports labeled ARC or eARC, start there before falling back to optical.

Common cable mistakes

Using TS where the gear expects a balanced TRS line. Neutrik warns this can cut the signal level because the balanced line is not being read correctly.
Confusing analog RCA with digital coax just because the plugs look the same. Sony says digital coax uses RCA-type connectors, but it is its own digital format.
Choosing optical when you actually want HDMI control features. Sony says optical-only connections do not provide some HDMI-dependent functions.
Assuming connector size equals sound quality. In most normal setups, correct signal type and secure fit matter more than the mere fact that the plug is 3.5 mm or 6.3 mm.

Bottom line

Pick the cable that matches the signal path, not the label on a store shelf. XLR and TRS are the safest starting point for balanced pro-audio connections, TS works for many instruments, RCA still belongs to consumer line-level gear, optical and digital coax are legacy digital links, and HDMI with ARC or eARC is usually the best home-theater audio path when the ports are available.