How Do Headphone Jacks And Plugs Work? ( Wiring Diagrams) - My New Microphone

It’s easy to plug your headphones (and other devices) into the right jacks or ports and make them work…until it stops working. Learning how headphone jacks and plugs work electrically will greatly help us understand signal flow and device compatibility, as well as improve our troubleshooting skills.

how do headphone jacks and plugs work? headphone jacks (male) connect to headphone jacks (female) to make an electrical connection to allow audio signals to flow. Although the purpose is the same, the size, specific wiring, inclusion of a microphone, connection quality, and compatibility differ from connector to connector, plug to plug, and plug to plug.

Reading: Headphone jack wiring diagram

In this article, we’ll take a look at the inner workings of these various headphone jack sizes, wirings, and qualities to better understand how they work in general, and how they work in conjunction with headphone jacks.

related article: how do headphone jacks and plugs work? (+ wiring diagrams)

the difference between a headphone jack and a headphone jack

When most people talk about headphone jacks, they’re referring to both the female port connectors and the male connectors at the end of headphone cables.

however, technically speaking, the headphone jack is the female port and the headphone jack is the male jack. this is the case for any phone-style connector (with tip, ring, and sleeve connectors).

These are earplugs:

This is a headphone jack:

The same difference can be applied to the microphone connectors. For more information, see my article What is the difference between a microphone plug and a jack?

With that base of terminology, let’s get into the bulk of this article.

how do you connect the headphone jacks and plugs?

Let’s start by saying that not all headphone jacks and plugs are compatible.

For a headphone jack and plug to connect properly and have optimal signal flow, they must match in the following ways:

be the same size
have the same wiring scheme

Please note that there is some leeway in cabling compatibility. Note, too, that just because a plug fits into a jack doesn’t necessarily mean it’s compatible. we’ll address these issues later in this article in the headphone jack and plug compatibility section.

Basically, headphone jacks and plugs are single connectors with multiple (2-5) conductors within their design. For a headphone plug to work with a headphone jack, the conductors must be properly aligned in the correct format to transfer the proper audio signals.

It is important to note that headphones are transducers and are inherently analog devices. analog audio signals are simply AC (alternating current) voltages. These signals are transmitted through cables that conduct electricity.

The strands of a headphone cable fit internally to the individual conductors of a cable plug. the audio source connector also has individual conductors that are wired to carry specific signals.

The idea is to make contact between the connector and the plug conductors to allow analog audio signals to flow from the source through the cable and to the appropriate headphone drivers according to the wiring diagrams.

In the vast majority of cases, we cannot see the physical connection between a headset plug and a jack without deconstructing the jack. the following is a simplified cross-sectional diagram of a jack-plug connection:

so that’s the basic idea of how headphone jacks and plugs work. they act as conductive connections that allow electrical current to flow from one place to another (from the audio source to the headphone drivers).

In this article, we’ll talk more about sizes and wiring standards for headphone jacks/jacks and look at compatibility.

jack/headphone jack sizes

Let’s start by looking at the different sizes of connectors and headphone jacks. they are:

2.5mm
3.5mm
4.4mm</li
6.35mm

2.5mm (3/32 inch)

The 2.5mm headphone jack/jack is not very common, but is worth mentioning here for completeness.

This plug/headphone jack is still used regularly on two-way radios (walky-talkies) and some video cameras.

2.5mm headphone connections are typical unbalanced mono (tip-sleeve) or unbalanced stereo (tip-ring-sleeve) connectors.

3.5mm (1/8″)

The 3.5mm headphone jack/jack is the most common for wired headphones.

This is the connector found on older smartphones, laptops and tablets, and some audio mixing consoles and field recorders.

3.5mm headphone connections are typically unbalanced stereo (tip-ring-sleeve) or unbalanced stereo plus microphone (tip-ring-sleeve) connectors.

4.4mm

4.4mm is a relatively new headphone jack/jack.

the 4.4mm standard is called a pentaconn and is found in some hi-fi products, especially from sony.

sony listed in the top 13 headphone brands in the world for my new microphone.

the pentaconn standard is wired as balanced stereo with a trrrs (tip-ring-ring-ring-sleeve) connector.

6.35mm (1/4 in.)

The 6.35mm “quarter inch” jack and plug are what you’ll typically find when connecting electric musical instruments. plugs/jacks used for instruments are often unbalanced and wired as ts (tip-sleeve).

However, the 6.35mm jack is also used for headphones, although it is typically wired as an unbalanced (tip-ring-sleeve) stereo plug.

The 6.35mm headphone jack/jack is found on many audio interfaces, headphone amplifiers, mixing consoles, and recording devices.

size adapters

Of the 4 sizes listed above, the 3.5mm (1/8″) and 6.35mm (1/4″) phone jacks are the most common.

luckily, there are adapters to convert between connector/plug sizes effectively. These adapters even come as plug-to-plug or plug-to-plug, in addition to direct plug-to-plug and plug-to-plug adapters.

For a detailed article on headphone jack and plug sizes, check out my new microphone post titled Differences Between 2.5mm, 3.5mm & 6.35 mm headphone jacks.

headphone jack/plug cables

In the headphone jack/plug size section, I briefly mentioned tip, ring, and sleeve connections. these terms refer to the different conductors in the connectors themselves that have their own cables with the headphone cable and carry their own audio line.

This section will explore the wiring standards used in headphone jacks and plugs and explain how they connect to each other and how they effectively transfer audio signals from the audio source to the headphone drivers.

stereo vs. mono audio

Most headphones are wired to accept stereo audio, since stereo is the standard for music.

however, some headsets (and in particular headsets) only require mono audio and are designed that way.

To carry mono, a headphone jack must have at least 2 conductors: 1 signal wire and a return wire (which also often acts as ground). the easiest way to do this is through a ts (tip-sleeve) connection.

stereo audio requires at least 3 conductors: a left channel audio signal cable, a right channel audio signal cable, and a ground/common return cable.

Note that mono and stereo headphones may have more than the conductors needed for microphone integration or balanced signal transfer.

balanced vs unbalanced audio

Most headsets use unbalanced audio, although there are exceptions.

Unbalanced audio is wired with a signal cable and a return cable. the return wire often functions as the ground wire. these two lead wires complete a circuit and allow an audio signal to “travel” from a sound source to a headphone driver.

Unbalanced audio is fine for transmitting audio over short cable lengths (such as headphone cables), but will degrade signals, especially in the high end, over any significant length.

Balanced audio is wired with two signal cables: one to carry the signal with positive polarity and the other to carry the signal with negative polarity.

Having equal but opposite signals on the two wires effectively doubles the voltage swing on a connected headphone driver, leading to a stronger signal transfer. while one wire “pushes” current on one side of the controller, the other wire “pulls” current from the other side of the controller into the circuit.

Balanced audio inputs effectively add up the differences between the two signal cables through a differential amplifier, allowing for a stronger signal with excellent protection against any interference or noise common to both conductors. therefore, it is common for long cable runs and for situations where clean audio with low noise is required.

Microphones, for example, output relatively low level audio signals that are more susceptible to electromagnetic interference (induced noise will be more noticeable compared to a mic level signal than a line level signal) . therefore, all professional microphones use balanced lines to transmit their signals.

It is important to note that stereo headphones require two different balanced or unbalanced audio signals: one for each driver.

With that primer, let’s get into the various wiring schematics for headphone jacks and plugs.

ts (tip-sleeve)

the ts is the most basic telephone connector. allows a mono audio signal to be carried through the signal cable (tip) and the ground/return cable (sleeve).

to run the ts connector wires simply:

tip: signal cable
sleeve: return and ground cable

ts can be connected to a single headphone driver (in single-sided designs) or can be split to come up with two separate drivers.

ts headphone jacks and plugs are usually only found on 2.5mm jacks. Please note that 6.35mm TS “breakout cable” connectors are common for electric instruments, particularly electric guitar and bass.

trs (tip-ring-sleeve)

trs is common on headphone jacks/jacks as a carrier for unbalanced stereo audio.

the unbalanced trs connector is wired as follows:

tip: left channel audio signal cable
ring: right channel audio signal cable
sleeve: common return cable and ground

In this configuration, the sleeve wiring is split at the y of the cable and connected to both controllers.

The trs unbalanced stereo wiring scheme is used on 2.5mm, 3.5mm and 6.35mm headphone jacks/jacks and is common in professional headphones.

Note that another common wiring standard for trs connectors/plugs is balanced mono, although this is never really used in headphone design. balanced mono trs are typically used in pro audio patch bays and studio monitor and speaker connections.

trrs (tip-ring-ring-sleeve)

the trrs is another very common headphone jack/plug. has gained popularity with the rise of headphones that include a microphone in their design.

many of our digital devices (smartphones, laptops, tablets) have 3.5mm trrs connectors to accommodate these earphones and microphones and headphones.

TRRS cabling is primarily used in 3.5mm headphone jacks and typically follows the AHJ (American Headphone Jack) standard set by the CTIA (Cellular Telecommunications and Internet Association). let’s take a look at this standard.

ctia standard

tip: left channel audio signal cable
ring: right channel audio signal cable
ring: common and ground return wire
sleeve: microphone audio cable

In these headphones, the common return (second ring) is divided into three parts and connects to the microphone element and both headphone drivers.

an older standard worth mentioning is omtp. is very similar except for one important change.

omtp standard

tip: left channel audio signal cable
ring: right channel audio signal cable
ring: microphone audio cable
sleeve: common and ground return cable

In this standard, the sleeve is also divided into three parts and connects to the microphone element and both headphone drivers.

trrrs (tip-ring-ring-ring-sleeve)

the trrrs connector is used on the rare 4.4mm pentaconn connector.

This specialized headphone jack/jack outputs balanced stereo to compatible headphones and is connected as follows:

tip: left channel audio (positive polarity)
ring: left channel audio (negative polarity)
ring: right channel audio (positive polarity)
ring: right channel audio (negative polarity)
manga: earth

If we remember the description of balanced audio, we know that there is no need for a return cable as we have a positive polarity and a negative polarity cable to connect to the headphone driver.

There is no common return lead on the 4.4mm pentaconn trrrs standard, which improves clarity by minimizing crosstalk due to the lack of a common return. balanced audio is also louder due to the nature of balanced versus unbalanced audio.

For a detailed read on the various headphone audio wiring schemes, check out my article, which takes an in-depth look at how headphone cables carry audio.

headphone jack and plug support

At the beginning of this article, I mentioned that headphone jacks and plugs can be compatible even if their drivers don’t match. I also said that headphone jacks and plugs might not be compatible even if they are the same size.

Let’s clear up some of this confusion by looking at specific examples:

compatibility between trs & trrs jacks/plugs

Imagine a scenario where we have a couple of the following:

headphones with 3.5 mm trrs connector
headphones with microphone and 3.5 mm trrs connector
smartphone with 3.5 mm trrs connector

the smartphone will most likely have a trrs connector as it is designed as an input/output device, capable of accepting a microphone and outputting a headphone signal. Let’s assume for this example that you use the ctia standard mentioned above.

once again, the ctia standard is:

tip: left channel audio signal cable
ring: right channel audio signal cable
ring: common and ground return wire
sleeve: microphone audio cable

so we know that a 3.5mm trrs headphone+mic (assuming ctia standard) is compatible with the headphone jack because the wiring schematics match and the sizes are the same.

However, when we connect the basic 3.5mm trs unbalanced stereo headset to the smartphone, they work perfectly. why is that?

well the tip and ring of the trs plug and trrs connector match perfectly. the ground/return wire is also connected. the trrs connector sleeve, which is designed to accept the microphone signal, simply connects to the ground wire of the headphone trs connector.

Of course, this is not a perfect connection, but they are still compatible nonetheless.

incompatibility between trrs (ctia) & trrs connectors/plugs (omtp)

it is important to know the difference between the older omtp standard and the newer ctia standard for unbalanced stereo headphone + unbalanced microphone signals.

Although the tip and first ring are fully compatible (left and right headphone audio), the common return and microphone signal cable (on the second ring and sleeve) are incompatible, causing the omtp and ctia standards are incompatible with each other.

size adapters

There are many size adapters on the market to adapt your headphone plug to a specific jack.

The most common adapters are 3.5mm trs to 6.35mm trs and 6.35mm trs to 3.5mm trs, but there are many others on the market.

wiring adapters

some wiring adapters help improve connectivity between headphone plugs and jacks that don’t have exactly the same connections (for example, the imperfect trs plug to the aforementioned trrs jack).

use headphone jacks to connect devices other than headphones

It is sometimes possible to connect devices other than headphones to the headphone jacks. Let’s move on with our discussion.

speakers

Most speakers are designed with a relatively low impedance to accept speaker level signals and therefore will not function properly if connected to a headphone output.

However, many handheld/mobile speakers are designed to plug into the headphone jack of smartphones, laptops, etc.

the jbl charge 3 (link to check price on amazon) is a bluetooth speaker that has a wired input that can easily accept signals from a headphone output.

jbl is featured in the following my new microphones articles: • top 14 headphone/headphone brands in the world • top 11 home speaker brands to know and use • top 11 subwoofer brands (car, pa , home and studio) • top 11 pa speaker brands you should know and use • top 10 speaker brands (overall) on the market today • top 11 car audio speaker brands in the world • Top 11 sound bar brands on the market • Top 8 portable bluetooth speaker brands on the market

auxiliary entries

You’ve probably done this before when connecting a smartphone to a car’s aux input. many home sound system amplifiers also have auxiliary inputs that can be used to accept headphone level signals.

for more information on the differences between headphone jacks and auxiliary outputs, see my article on auxiliary (auxiliary) jacks & same headphone jacks?

microphones

Microphones can be connected via dedicated headphone jacks designed to accept microphone signals. The TRRS headphone jacks discussed above are capable of accepting microphones that connect via 3.5mm phone jacks.

To read about some of my recommended trrs microphones, check out my article the 4 best external microphones for android smartphones.

related article: how do microphones work? (a helpful illustrated guide)

How Do Headphone Jacks And Plugs Work? ( Wiring Diagrams) – My New Microphone

the difference between a headphone jack and a headphone jack

how do you connect the headphone jacks and plugs?