Differences Between 2.5mm, 3.5mm, and 6.35mm Headphone Jacks

Even though wireless headphones are very close to supplying the same capabilities as wired, they’re still not quite there yet. That’s why wired headphones, along with the different jack varieties, are still used.

While the most common and widely recognized is the 3.5mm (1/8 inch), there are also two other sizes regularly used. These are the 2.5mm (3/32 inch) and the 6.35mm (1/4 inch), each with their own purposes.

In this differences between 2.5mm, 3.5mm, and 6.35mm headphone jacks guide, I will explain everything you need to know about the different types of headphone jacks and plugs.

Jacks, Plugs, Ports, and Sockets

Before we get started, I think it’s important to cover the fact that there is no standard term to describe the two main components.

You might have heard all of these terms used at some stage. Those terms are jacks, plugs, ports, and sockets. I think the easiest way to clear this up is to use some universal terms to describe each of them.

Attention boys and girls…

The most common audio connection types are male and female. So, what are male and female audio connections? The male connection is usually designed to be inserted into a matching female connection. For example, the end of your headphone cable is inserted into your audio device.

The male connection type on audio products can be referred to as either a jack or plug. A female connection is often called either a port or socket. For the remainder of this guide, I will use the terms “jack” and “socket.”

Different Sizes

As you can probably tell from the name, each of these jacks and sockets is a different size. The most common size you will hear referred to is the diameter of the jack or socket. Furthermore, this is usually in millimeters (mm).

The length of each different jack is also different, not only the diameter. Typically, 2.5mm jacks have a standard length, while the 3.5mm and 6.35mm jacks can have some variances to their lengths.

Diameters and lengths…

While there are some variances to lengths with two of the diameters, they are usually within a particular range for each. Starting with the 2.5mm jack, its length will almost always be close to 11mm (0.43 inches).

The 3.5mm jack is between 14mm and 17mm (0.55 and 0.69 inches) in length. For the 6.35mm jack, its length will be between 30mm and 31 mm (1.18 and 1.22 inches). The largest variance in lengths is the 3.5mm jack.

Same but different…

While the 3.5mm jack has the most variances in length, it is also the most common type of audio jack. Most headphones will be fitted with a jack 15mm in length. These are compatible with most computers, smartphones, tablets, personal music players, and more.

Next, I will cover the different types of audio jacks and sockets in more detail as we learn about the differences between 2.5mm, 3.5mm, and 6.35mm headphone jacks.

6.35mm (1/4 inch) Jacks and Sockets

The area you are most likely to find a 6.35mm (1/4 inch) jack or socket is when using an amplifier with musical instruments. If you’ve ever plugged a guitar or bass into an amplifier, chances are you’ve used a 6.35mm (1/4 inch) jack and socket.

Musical and professional equipment…

It looks just like the jack you would be used to on the end of your headphones, just a bigger version. Besides musical instruments, other places you might find this style of jack and socket are on professional headphones, audio interfaces, and mixing consoles.

3.5mm (1/8 inch) Jacks and Sockets

As mentioned, this is the most common style of jack for headphones today, but that’s not the only place you’ll find them. This is also the most common size found for auxiliary (or aux) cables often used with wireless speakers, car stereos, computers, and more.

Find them everywhere…

Due to the jacks being so common, this means that you can find the matching sockets in many places too. You’ll find them on smartphones, tablets, computers, music players, voice recorders, car stereos, home stereos, mixing consoles, and more.

2.5mm (3/32 inch) Jacks and Plugs

This is the least common type of jack and plug of all. Although it can still be found in some products today. The place you’re most likely to find a 2.5mm jack is on two-way radios, cordless landline phones, and on some video cameras.

Quick, before they’re gone…

With wireless technology moving ahead quickly, you’ll see less and less of these jacks and sockets. The 2.5mm jack and socket have almost all but vanished, as with its smaller size, it is prone to snap more easily.

Not Just for Headphones

Even though all of these jacks are commonly called “headphone jacks,” that doesn’t mean that’s all they’re used for. While this is by far their most common and recognized use, hence earning the name, they can be found in many other applications.

With a larger variety of uses now becoming more recognized, you might hear the newer, more accurate term is used. Instead of “headphone jack,” these same items are now commonly called an “audio jack.”

A variety of uses…

Here are some other places you can commonly see these jacks and sockets used. Microphones, audio in/audio out (auxiliary), headsets, loudspeakers, musical instruments, studio equipment, home theaters, plus lots more.

Connectivity Capabilities

The size and length isn’t the only difference between audio jacks and sockets. Each type has different connection capabilities and is wired slightly differently. This allows them to send and receive different types of signals. So, next, I will cover in detail all the different connection capabilities currently available.

Tips, rings, and sleeves…

Each jack and socket could be wired differently, changing the types of signals they are capable of carrying. They will have multiple conductors and internal wires, which can be identified using tips, rings, and sleeves.

The tip, as you would expect, is the very point of the jack. For jacks with rings, they are located in the middle section, usually separated by a rubber ring. The sleeve can be found at the very base of the jack.

Multiple variations…

At the very least, a jack will contain a tip and a sleeve. Depending on how many signals are required, a ring can be added. Each ring introduces an extra wire, therefore increasing the number of signals being sent along the cable.

Sockets follow the same process, however, in reverse. The only jacks and sockets that aren’t interchangeable are TS (tip sleeve), as it could potentially cause a short circuit. Any jacks or sockets with rings can be used universally; however, all the functions might not operate.

Here is a breakdown of the different connection varieties…

TS – Tip Sleeve Jacks and Sockets

With TS connections, there are two wires found within the cable. One wire is attached to the sleeve, providing both ground and return channel for the audio. The second wire, which is attached to the tip, provides a mono audio channel.

Mono audio only…

This type of connection isn’t often found in headphones as they more commonly use stereo rather than mono audio. The area you’ll most likely see a TS cable is with a guitar or bass, as they only require a mono signal.

TRS – Tip Ring Sleeve Jacks and Sockets

TRS connections are much more common as they provide a stereo audio signal. This introduces an extra wire within the cable, making three in total. A TRS wire connection follows a very similar pattern to a TS jack.

There are two different types of TRS wiring, with the most common being unbalanced. The sleeve wire once again provides both ground and return channel. This time, however, the tip wire provides the left channel, and the ring wire provides the right channel.

Balanced and unbalanced…

With an unbalanced connection, which is most commonly found in headphones, there is only a single signal being sent. It is then diverted to the left and right sides of your headphones or speakers.

For a balanced stereo connection, two cables are required, which is why you won’t find them in headphones. The wiring is slightly different. The sleeve is still the ground and return channel. However, the tip is the positive signal, and the ring is the negative signal.

If you plug a set of headphones or speakers into a balanced socket, the sound will be terrible. This is due to equal signals being sent to the opposite polarities of each driver.

TRRS – Tip Ring Ring Sleeve Jacks and Sockets

With most headphones now offering a microphone function for use with smartphones, computers, and tablets, an extra channel is required. Adding an extra ring provides an extra wire and channel. The wiring for TRRS connections follows two different standards.

Before 2015 the OMTP standard was followed, using the following connections. Tip for left channel, ring for right channel, the second ring providing a microphone channel, and the sleeve still used as ground and return.

The latest standard…

Since 2015 the standard has now moved to CTIA for nearly all consumer-grade electronic devices. The connections are tip for left channel, and ring for right channel, only this time the second ring is now the ground and return, while the sleeve is now the microphone channel.

Different Types of Connections

You now have a better understanding of the differences between 2.5mm, 3.5mm, and 6.35mm headphone jacks. But not all headphones use those connections. There are many other types of connections available. I will cover other types of headphone connections you are likely to encounter.

Lightning

You might be familiar with the Lightning connector if you’ve ever owned an iPhone or iPad. This is Apple’s proprietary connection method for charging their devices. Since the release of the iPhone 5, Apple has removed the headphone socket.

Because the 3.5mm headphone socket wasn’t replaced, a range of headphones is now available with a Lightning connection. This is in place of the 3.5mm jack, although it poses a problem if you wish to charge your phone and listen to audio simultaneously.

USB

Many headphones and headsets designed for computers use a USB connection. There are two main types of USB connections used currently, with the most common being the larger USB Type-A.

Now that many electronic devices are following Apple’s lead, you can now also find headphones utilizing the newer, smaller USB Type-C connection. If things keep heading in this direction, you will start to see many more of this style.

XLR

An XLR connection is usually found in professional-grade equipment like studios, mixers, and audio racks. You might have seen them in older analog microphones, amplifiers, or on PA (Public Announcement) systems.

Some professional headphones and headsets have an XLR connection. The cable is often detachable and sometimes offers a variety of different connection options.

Adapters

With all these different types of connections available, what if your jack doesn’t match your socket? Luckily there are more affordable, high-quality adapter options available than there are jack and socket varieties.

Something to keep in mind when searching for an adapter is the number of channels required. Do you need TRS, TRRS, or TS? They are all available, but make sure you know what’s required first. Here are some examples of good quality adapters I recommend…

VCE – 6.35mm Male to 3.5mm Female Adapter

This adapter from VCE allows users to plug a 3.5mm jack into a 6.35mm port. Finished with 24K gold-plated connectors, this improves conductivity while reducing chances of corrosion. It is a TRS stereo sound.

ANTOBO – 3.5mm Male to 6.35mm Female Adapter

If you find you need to do the exact opposite, the ANTOBO adapter allows you to plug a 6.35mm jack into a 3.5mm socket. Made from pure copper, it offers superior conductivity, minimal signal loss, and prevents corrosion. Again, it uses TRS for stereo sound.

JXMOX – USB Type-C to 3.5mm Female Adapter

If you’ve purchased a new smartphone or tablet that doesn’t have a headphone socket, but you have quality headphones, this could be for you. Plug your 3.5mm jack into a USB Type-C port with this quality adapter from JXMOX. A TRRS socket is used.

DESOFICON – 2-in1 Lightning to 3.5mm Female Adapter

Remember the issue I mentioned with using a Lightning socket for your headphones? Well, DESOFICON has come up with a solution. This 2-in-1 adapter plugs into your iPhone or iPad’s Lightning socket and then provides both an additional Lightning socket along with a 3.5mm female socket. A TRRS socket is used.

Need Great Headphones or more Information about Headphone Connections?

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And don’t miss our handy guides on How to Fix a Bent Headphone Jack, How Do Headphone Jacks and Plugs Work, How to Remove a Broken Headphone Jack, How to Fix Echo in Headphones, and Are Aux (Auxiliary) Connectors & Headphone Jacks the Same for more useful information.