Headphone Jack Sizes and Plugs – All You Need to Know

Headphone jacks are fixed ports that transmit audio signals between the headphones and the device. Headphone plugs are the male connectors located at the end of a cord, while the jack refers to the female receiving end. There are many different sizes of headphone jacks and plugs.

Often the headphone plugs have cylindrical-pin ends while the jacks are round, hollow sockets. Different devices have different jacks and plugs for higher quality audio, and you have to get familiar with the terminology to figure out which plugs you need or if you need an adapter or not.

The headphone jacks are often installed on the devices and can not be easily changed. So users should figure out which plugs to use with the jack ports. There are many different types and sizes of plugs and jacks with different names.

With this guide, I will try to help you understand all of them and which types and sizes you would need with your gear.

Difference Between The Headphone Jack And Headphone Plug

Headphone jacks and plugs are some of the most misused terms when talking about music gear. Headphone plugs refer to the male ends at the end of headphone cords, while headphone jacks are actually the female ports installed on the devices. However, the term ‘jack’ is used both for male and female ends, leading to confusion. 

In the article, I will refer to the ports as jacks and the male connectors as plugs to avoid this confusion and be precise about the different parts.

The 4 Types of Headphone Plugs

There are 4 common types of headphone plugs that are often used on different devices. The names of the plug types show how many conductors the plug consists of. The letter T is for the tip, R is for the ring, and S is for the sleeve. 

TS Connectors

The most basic type of headphone plug is the TS (Tip-Sleeve) type of connector, which features 2 conductors. The sleeve acts as a ground, and the tip is responsible for the audio signal transmission.

TS connectors only transmit mono audio signals and perform best with short cables. With long cables, they may experience audio distortion. They are mainly found in 2.5 mm sizes and are used for instrument-amp or headphone connections.

TS jacks and plugs can only transmit unbalanced mono audio signals. One part is responsible for audio signals, while the other part acts as a ground and return wire.

TRS Connectors

TRS (Tip-Ring-Sleeve) connectors feature 3 conductors. The addition of the ring allows the audio signal to be balanced mono or unbalanced stereo signal types. This means you can use these headphones for stereo sound without a microphone or mono sound with a microphone signal.

This is one of the most common headphone plug types that can be seen on most headphones. With the addition of another conductor, these plugs can carry microphone signals which are referred to as unbalanced audio signals.

With a balanced mono system, the tip and the ring are responsible for the negative and positive signals respectively while the sleeve serves as the return wire. In an unbalanced system, the tip is responsible for the left channel signals, the ring from the right channel signals while the sleeve serves as the ground-return wire.

TRRS Connectors

TRRS (Tip-Ring- Ring-Sleeve) connectors are equipped with 4 conductors. These types of connectors support unbalanced stereo audio with a microphone signal added at the same time. They are up to the standards set by Cellular Telecommunications and Internet Association (CTIA).

TRRS connectors are often used with computers, smartphones, and video game consoles. They allow the users to have stereo sound with the microphone signal. The tip and the two rings are responsible for right and left channel audio signals as well as the ground return path, while the sleeve serves as the microphone signal wire.

TRRRS Connectors

The last common headphone plug type is TRRRS (Tip-Ring- Ring- Ring-Sleeve) connectors. Equipped with 5 conductors, these headphone plugs are used in professional music production gear as they support balanced stereo signals. 

The reason behind the professional audio systems that use TRRRS is that it features two balanced channels with double left and right channels to produce a proportional stereo signal with more clarity. 

The tip and the first ring acts as the left channel with positive and negative polarity, respectively. The second and third rings serve as the right channel with positive and negative polarity, while the sleeve is the ground wire.

The 4 Most Common Sizes Of Headphone Jacks And Plugs

There are 4 common headphone plug sizes; 2.5 mm, 3.5 mm, 4.4 mm, and 6.35 mm. They are all used for different audio applications and can have different types. When talking about headphone jack sizes, the outside diameter of the sleeve conductor is taken into account.

2.5 mm

The smallest headphone jack/plug size is 2.5 mm, which is also called the micro jack. They are TS-style plugs and only transmit audio transmission. They are mainly used with mono headphones for video cameras and rarely with some mobile phones.

This is a very rare headphone plug/jack size, as they were used for smartphones, but the standard did not hold, and manufacturers started using mini jacks instead.

3.5 mm

3.5 mm headphone jacks/plugs are the most common size for headphones. 3.5 mm sized jacks and plugs are used for both TRS and TRRS style systems which are preferred across many laptops, smartphones, portable audio players, and tablets.

4.4 mm

4.4 mm headphone plugs are relatively new and rare. They are mainly preferred by Sony’s Pentacon plugs and jacks which are designed for balanced stereo audio signals. The Pentacon plugs are TRRRS style plugs with 5 conductors which deliver audiophile quality sound.

6.35 mm

The largest known jack/plug size is 6.35 mm and is mainly used for instruments rather than headphones. However, some headphone amplifiers and audiophile-quality headphones use this size headphone plugs. 

6.35 mm jacks and plugs were the first headphone plug size used with vintage audio equipment. Today they are mainly used for professional audio equipment. There are different styles with mono or stereo sound. 

The mono sound models are used for musical instruments like guitars and synths, while the stereo version plugs are used for headphones.

Other Types Of Headphone Jacks

There are 3 other types of headphone jacks worth mentioning such as the Audio Lightning Jack, the USB Jack, and the USB-C Type Jack.

Let’s go into more detail about each.

Audio Lightning Jack

Apple introduced audio lightning jacks in 2012, which gradually took the place of 3.5 mm headphone jacks on Apple iPhones. Starting with the iPhone 7, all the models are only equipped with audio lightning jacks responsible for audio transmission. 

The sound quality is significantly improved as they have built-in digital-to-audio converters, which allow for audio transmission without any distortion or compression. It also allows for more features as the device can be charged from the lightning port, and you can use the port for different purposes that require any kind of digital inputs.

USB Jack

USB Jacks are mainly used for gaming purposes with laptops and PCs. They are designed for gaming headsets of eSports players as this type of connection provides a clear and resonant sound. This is because USB jack headsets often have a built-in amplifier.

USB Jack headsets consume significantly more power than traditional headphones. It is not a problem if you are using them with computers, but otherwise, they can drain your battery pretty quickly.

USB-C Type Jack

USB C-Type jacks have been around for a while, used mainly by some smartphone brands like Samsung, Huawei, Xiaomi, and Google. Just like Apple switched to lightning jacks for audio transmission for better sound quality, the other brands started using USB-C for the same purpose.

Adapters

To use different plugs with different sizes or types of jacks, you will need to use adapters. The adapters act as the bridge between incompatible plugs and jacks to connect them successfully.

The most common adapter is the 3.5 mm to 6.35 mm jack adapter, which is commonly used for connecting headphones to amplifiers. Another adapter often used is the audio lightning jack to 3.5 mm jack adapter, allowing users to connect standard headphones to iPhones and iPads.

There are many different adapters today that you can use to connect any headphone plug to almost any headphone jack.

Structure Of A Headphone Plug

The structure of a headphone plug consists of conductors, which are tips, sleeves, and rings, along with the insulating bands.

The conductors are the connection points that complete the electrical circuit between the plugs and jacks. Every plug has a minimum of 2 and a maximum of 5 conductors. The conductors consist of tips, sleeves, and rings.

As the name suggests, the tips are the ends of the plugs. The sleeves are the rear part of the plugs, and they decide the diameter of the plug. The rings are the middle parts that separate the sleeves and the tips.

All of the plugs have at least two conductors, the tips and the sleeve. Every conductor is separated with a black band which is called the insulating band. The ring count of a plug determines the name of the plug like TS, TRS, TRRS, TRRRS plugs. 

Audio and Signals

There can be two types of audio signals between the headphones and audio sources, which are monaural (mono) and stereophonic (stereo). Mono audio uses only one channel, while stereo audio uses two separate channels as left and right.

While mono signals are the audio reproduces from only one position, stereo signals are created by two different channels, which results in the way of audio reproduction closer to the natural hearing experience.  

This is a pretty important factor in headphones as specific types of jacks and plugs support stereo audio signals, which you should look for in a decent headphone.

Another thing to know is balanced and unbalanced audio. This topic can be a bit overwhelming and confusing, so I will try to summarize it as much as I can. Most of the headphones use unbalanced audio signals, but there are some exceptions.

Balanced audio refers to the system with two signal wires; one positive and one negative wire. The unbalanced audio means there is only one signal wire along with a ground/return wire. 

So there are four types of audio signals; unbalanced mono, balanced mono, unbalanced stereo, and balanced stereo. For unbalanced mono, at least 2 conductors are needed; for balanced mono and unbalanced stereo, at least 3 conductors are needed, and for balanced stereo, at least 5 conductors are needed.

Summary 

Headphone jacks and plugs come in many different styles and sizes, which can be overwhelming for users who are not familiar with the terms and different signal types. However, after learning about the basics, you can easily understand how the audio is transmitted between the headphones and the audio source.

This way, you can figure out which audio signal suits you and if you need an adapter or not with your gear. You can also know which headphones to use for which purpose and consider the conductor count and jack size when looking for a new headphone for the best sonic experience possible.