Are Headphone Jacks The Same As Microphone Jacks?


The way in which audio is sent to or sent from headphones and microphones will vary between different devices and different connectors (jacks and plugs). There may be confusion about the differences between headphone jacks and microphone jacks when learning about all the different audio connectors.

Are headphone jacks the same as microphone jacks? Although microphone jacks and headphone jacks may use the same size connectors or combine into the same connector, the actual connections and signal flow are different: Headphone jacks send audio signals to a headphone plug; Mic jacks receive incoming audio signals from a microphone plug.

The main difference between headphone jacks and microphone jacks is that one sends audio signals, whereas the other receives audio signals. In this article, we’ll consider the differences between headphone jacks and mic jacks with regard to their function and structure.


Are Headphone Jacks The Same As Microphone Jacks?

To understand the differences between headphone jacks and microphone jacks, we need to establish some identifying criteria and assess the differences. These criteria will strictly be based on the function and structure of each type of jack. 

There is a wide variety of audio connectors. The shape, size and number of conductive pins in the design will complement the audio requirements of the connected devices in question.

In the era of wireless internet, audio jacks are becoming less popular but are still relevant when transferring audio signals in many professional and consumer systems.

By answering the following questions, we can establish some criteria for differentiating headphone jacks from mic jacks: 

Identifying the differences and similarities in the responses for each of these questions will provide a clearer picture of what makes headphone jacks distinct from microphone jacks. Before that, we will provide a brief overview of the structure and design of audio jacks.

What Is The Structure Of An Audio Jack?

Before we can fully understand how headphone jacks and mic jacks differ, we need to understand the structure of audio jacks. Audio jacks generally share the same components and features. There are different sized jacks and variations in how the jacks are constructed and manipulate audio signals.

Typical audio jacks and plugs are composed of three main conductive connections: tip, ring, and sleeve.

The sleeve of a jack generally acts as ground and can sometimes act as a return path of mono unbalanced signals (when there is only a sleeve and tip in the connection).

The tip and ring(s) of the jack/plug are designed to carry audio signals. The number of rings of a given microphone or headphone jack will depend on the specifics of the audio being transferred.

Let us consider the two most common jack configuration we’ll find:

  • TRS: As the acronym suggests, TRS jacks are composed of three main conductors, including tip, ring and sleeve. This is a stereo cable where the tip transfers the left stereo channel, and the ring is responsible for the right stereo channel. The sleeve grounds the cable.
  • TRRS: These jacks are composed of four main parts, including a tip, ring, ring, and sleeve in this respective order.

TRS jacks/cables/plugs can carry balanced audio (a method where a mono audio signal is carried on both signal wires – the tip and ring – for improved noise-cancellation/isolation). This is useful for microphone audio.

TRS jacks/cables/plugs can also carry unbalanced stereo audio (where the left channel would be carried on the tip and the right channel would be carried on the ring).

TRRS cables can be used to carry unbalanced audio (on the tip and first ring) while also carrying mono unbalanced audio (on the second ring). The sleeve would act as ground and also as a return for the unbalanced mono signal. This design can effectively combine a headphone jack and microphone jack into a single jack. It is how many stereo headsets and earphones with built-in mics are wired.

Generally speaking, smartphones and computers have TRRS connectors that are used as the output of a microphone or transferring video signals. Unlike TRS or TS connectors, TRRS connectors send and receive signals, which is a necessary feature for headphones with built-in mics and headsets since they are often used as input and output audio devices.

Additionally, there are three diameters used to classify headphone/microphone jacks: 2.5 mm, 3.5 mm, and 6.35 mm.

Related My New Microphone articles:
Do Microphones Output Balanced Or Unbalanced Audio?
Do Microphones Output Mono Or Stereo Signals?

Differences Between 2.5mm, 3.5mm & 6.35mm Headphone Jacks
Are Microphones Input Or Output Devices?
Are Headphones Input Or Output Devices?

How Do Microphone Jacks Work?

Microphones are responsible for reacting to sound waves and outputting electrical audio signals to their output plugs. Mic jacks, then, receive their microphone audio signals. Audio signals flow from the mic plug to the connected mic jack.

These output plugs usually take the form of male XLR cables, phones, or other connectors. Though XLR is most common, some microphones utilize the aforementioned “headphone-style” phono connectors (TS, TRS, etc.).

The audio signals pass through connections in a specific sequence: 

  • Mic signal flows from the microphone plug to the microphone jack 
  • From the microphone jack, the signal then flows to the mic input 

In the case of connecting a microphone to a microphone preamplifier, you would be using an XLR output. The XLR output would mediate the flow of the audio signals from the microphone to the preamplifier.

Something to keep in mind with microphones is that the XLR plug always sends audio signals to the XLR or microphone jack. The XLR plug is usually referred to as the male connector, whereas the XLR jack is called the female connector. This arrangement for microphone connections is alterable with adapters.

Regarding microphones that use phone connectors or multi-connectors, the mic cable is usually part of the microphone design. Assuming the mic input is correctly wired, this makes connecting the microphone a simple process. As for microphones using phone connectors or multi-pin connectors, the mic cable is often part of the mic design. 

Related My New Microphone articles:
What Is The Difference Between A Microphone Plug And Jack?
What Do Microphones Plug Into? (Full List Of Mic Connections)
How To Connect An External Microphone To A Smartphone
How To Connect A Microphone To A Computer (A Detailed Guide)

How Do Headphone Jacks Work?

Before you can understand how headphone jacks work, we need to understand the underlying technology. Your headphones are a pair of transducers that convert electrical audio signals into sound waves. These transducers are connected via wire to a headphone jack to receive the necessary current. This current sent to the headphone transducers is transformed into air pulses in your ear by interacting with a magnet.

The headphone jack facilitates this process by connecting to the current source of your smartphone or computer to complete the circuit and produce the sound output. This may sound simple on the surface, but headphones jacks have a complex design and play a unique role in the circuit. 

You can think of your headphone jack as a connector, which transfers audio signals from your headphones to a computer (and vice versa in the case of headsets). This means that your jacks allow for the transmission of audio signals in two directions: the jack transfers signals from your headphones to your computer and from the computer back to your headphones (again, if the headphones/headset have a built-in microphone).

Related My New Microphone articles:
Are AUX (Auxiliary) Connectors & Headphone Jacks The Same?
How Do Headphone Jacks And Plugs Work? (+ Wiring Diagrams)

Why & How Do Headphones Use Magnets?
How Do Speakers & Headphones Work As Transducers?


The Difference Between Headphone Jacks And Microphone Jacks

The main difference between headphone jacks and microphone jacks is the way they transfer audio signals. Both types of audio jacks may use XLR, phono or other connectors to mediate this transfer. 

Headphone jacks allow for the flow of audio signals to your headset and audio source, with the signals going in both directions. This multi-directionality of audio signals is necessary to complete the circuit and produce sound waves in your ears through your headset, and allow you to speak through your headset mic. 

Alternatively, microphone jacks strictly rely on the flow of audio signals from mic plugs to mic jacks and then to the mic input. This is a linear process, which makes sense considering there are only audio signals on the receiving end when speaking into a microphone. 


Conclusion

Although microphone jacks and headphone jacks share a similar structure, they both serve unique functions when it comes to sending and receiving audio signals. The main function of a headphone jack is to send audio signals to your headphone plug (and ultimately the headphone transducers). In contrast, mic jacks receive signals from the mic plugs (and ultimately the audio device). 

To make things simple, you can think of headphone jacks as a sender of audio signals and microphone jacks as the receiver of signals. Headphone jacks and mic jacks serve the opposite function, just as headphone plugs receive and microphone plugs send audio signals. 


What Is The Difference Between A Microphone Plug And Jack? A jack is a receptacle into which a plug is inserted. A mic jack is a female-type connector in a mic or mic cable. A mic plug is a male connector that is inserted into the jack. The XLR output of a professional mic is a mic plug. A mic preamplifier input is considered a mic jack.

Related article: What Is The Difference Between A Microphone Plug And Jack?

What are the differences between 2.5mm, 3.5mm & 6.35mm headphone jacks? The primary, most obvious difference is size. The numbers given refer to the diameter of the jack, but the lengths of the connectors are also different. Certain applications have certain standard sizes. In terms of wiring, various standards can be applied to each size jack.

Related article: Differences Between 2.5mm, 3.5mm & 6.35mm Headphone Jacks

Arthur

Arthur is the owner of Fox Media Tech and author of My New Microphone. He's an audio engineer by trade and works on contract in his home country of Canada. When not blogging on MNM, he's likely hiking outdoors and blogging at Hikers' Movement (hikersmovement.com) or composing music for media. Check out his Pond5 and AudioJungle accounts.

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