Can I plug microphone into headphone jack?
What is a microphone jack?
A microphone jack is a type of audio connector or port designed specifically to connect a microphone to an audio device like a speaker, phone, computer, or recording interface. Its main purpose is to accept the analog audio signal from a microphone and transmit it to the device for conversion into a digital signal.
The key difference between a microphone jack and a headphone jack is that a microphone jack is an input while a headphone jack is an output. A microphone jack allows you to input sound into a device, whereas a headphone jack lets you output sound from the device.
Some common microphone jack sizes are:
- 3.5mm – the most common size used on computers, mobile devices, and gaming headsets
- 6.35mm (1/4″) – standard size for professional audio gear like microphones and mixing boards
- XLR – commonly used for condenser microphones in studios and on stages
In summary, a microphone jack provides the crucial interface for connecting external microphones and transmitting analog audio signals into various devices. Its specific design accommodates microphones and differs from the output-focused headphone jack.
What is a headphone jack?
A headphone jack is an analog socket used to connect headphones, earphones, headsets, or external speakers to an audio device like a smartphone, tablet, laptop, or desktop computer (https://www.pcmag.com/encyclopedia/term/headphone-jack). The main purpose of a headphone jack is to allow the audio output signal from a device to be transmitted to headphones or speakers so the user can listen to audio.
A headphone jack is different from a microphone jack, which is used to input audio signals into a device. Microphone jacks are designed for the input of audio while headphone jacks are made for audio output. Most modern devices like smartphones have separate ports for headphone and microphone connections.
Some of the most common sizes for headphone jacks are 3.5mm and 2.5mm. The 3.5mm headphone jack, often referred to as a 1/8-inch jack, has been widely used on mobile devices like smartphones and portable media players. The larger 2.5mm jack is less common today but was used on older mobile phones (https://www.pcmag.com/encyclopedia/term/headphone-jack).
Differences between microphone and headphone jacks
There are several key differences between microphone and headphone jacks in terms of their wiring, impedance, and signal levels:
Wiring differences: Microphone jacks use a Tip-Ring-Sleeve (TRS) wiring configuration where the tip carries audio, the ring carries power, and the sleeve is ground. Headphone jacks use a Tip-Ring-Sleeve (TRS) wiring as well but the connections are different – the tip carries left audio, ring carries right audio, and sleeve is ground.[1]
Impedance differences: Microphones generally have very low impedance (<600 ohms) while headphones can have impedances ranging from 8 ohms to 600 ohms. The microphone jack expects a low impedance microphone to be connected.[2]
Signal level differences: Microphones output very low voltage/signal levels, while headphone jacks are meant to drive higher voltage levels needed for headphones. Microphone jacks amplify the low mic signal level, while headphone jacks are designed for stronger headphone driver signals.[1]
Can you plug a microphone into a headphone jack?
Physically it is possible to plug a microphone into a headphone jack, but it is not recommended for most use cases. This is because there are a couple issues that arise from trying to use a headphone jack as a microphone input.
One problem is an impedance mismatch. Microphones generally have much lower impedance than headphones. When you plug a mic into a headphone jack, the difference in impedance levels can result in the microphone audio signal being very faint or noisy.
Additionally, microphones output a much lower signal voltage than headphones typically receive. So even if you can physically connect a mic to a headphone jack, the signal coming from the microphone may be too quiet to be useful. You would likely have to boost the gain significantly, which also amplifies any noise.
While in some basic use cases it may be possible to plug a microphone into a headphone jack, such as for voice calls or speech recognition, the low signal levels result in poor audio quality. For any quality recording or other application requiring a clear microphone signal, it is better to use a proper external microphone designed for that purpose and connect it to a dedicated mic input.
Adapters for Connecting Microphones to Headphone Jacks
There are a couple different types of adapters that allow you to connect a microphone to a headphone jack:
Impedance Matching Adapters – Microphones and headphones often have different impedance levels. Microphones typically have lower impedance while headphones have higher impedance. An impedance matching adapter converts the impedance so the microphone can work properly when plugged into a headphone jack. These adapters are inexpensive and can be found on sites like Amazon.
Microphone Preamps – A preamp boosts and amplifies the weak microphone level signal so it is strong enough for the headphone jack. The preamp strengthens the signal so the microphone audio is clearly picked up when plugged into a headphone port. Preamps also often convert impedance. Quality preamps like the Shure A96F can improve microphone sound when plugging mics into headphone jacks.
Using one of these adapters allows microphones to work when connected directly to a headphone jack. The adapter adjusts the signal so the microphone is compatible. This prevents issues with weak signal levels or impedance mismatches that could occur otherwise.
Recommended ways to connect a microphone
There are a few recommended ways to properly connect a microphone to a computer:
Dedicated microphone jack – Most desktop computers and some laptops have a round microphone jack, usually colored pink. This allows you to directly plug in a microphone with a 3.5mm connector. Professional microphones may use XLR cables instead, requiring an audio interface (covered next). The microphone jack provides power to the microphone and gives you a way to record audio directly into the computer.1
USB microphone – Many modern external microphones connect via USB instead of 3.5mm. This allows them to work seamlessly on any desktop or laptop with a USB port, without needing a separate jack. USB microphones have built in audio interfaces and convert the signal digitally. They are plug-and-play on Windows and Mac. The USB connection powers the microphone and sends the audio signal to the computer.
Audio interface with microphone input – For professional XLR microphones, an audio interface is required to connect them to a computer. These convert the analog XLR signal into digital, letting you plug the mic into your PC/Mac via USB. Audio interfaces provide phantom power to the microphone, and high quality AD/DA conversion for best recording quality.2
Voice/Speech Recording Quality Comparison
When it comes to recording voice or speech, there are some key differences in audio quality between using a headphone jack, dedicated microphone jack, and USB microphone:
Headphone jacks are designed for outputting audio rather than inputting it. As a result, the audio quality when using a microphone plugged into a headphone jack is often lower compared to other options. The microphone preamps and analog-to-digital converters built into most computers and mobile devices are basic, resulting in higher noise floors and less dynamic range. This can lead to hiss, hum, and distortion being more noticeable in recordings.1
Dedicated microphone jacks like XLR or 1/4″ TRS provide better quality microphone preamps, ADCs, and shielding from interference. The mic inputs are optimized for the lower signal levels from microphones. This results in much lower noise floors, with some sources citing over 10dB improvement in signal-to-noise ratio (SNR) compared to typical headphone jack mic inputs.2 The improved SNR allows microphones to capture a wider dynamic range with less audible hiss.
USB microphones contain their own built-in mic preamp and ADC, bypassing the lower quality components used in consumer headphone and microphone jacks. They provide comparable quality to dedicated external mic preamps and interfaces. The digital USB connection also minimizes interference. However, audio quality depends on the specific USB microphone model and components used.
In summary, dedicated microphone connections like XLR or USB provide substantially better SNR, dynamics, and overall recording quality compared to basic headphone jack microphone inputs. However, headphone jacks may still be suitable for informal speech recording depending on the context.
Applications where headphone jack microphone can work
There are some casual use cases where plugging a microphone into a headphone jack can work decently enough:
For casual voice calls or chats, the microphone quality from a headphone jack may be sufficient. The convenience of using existing headphones with an integrated mic can outweigh the need for high quality audio during quick back-and-forth conversations over chat or voice apps. As long as both parties understand the limitations, headphone jack microphones can be handy for casual communications [1].
Using headphone jack microphones with voice assistants like Siri, Alexa, or Google Assistant can also work reasonably well. Voice assistants mainly listen for speech commands and queries in close proximity, which doesn’t require studio quality audio. The built-in mics on headphones connect easily to phones for quick voice assistant access [2].
While audio quality is low, headphone jack microphones can be used in a pinch for recording voice memos, podcasts, or other audio when no dedicated mic is available. The resulting recordings will likely capture ambient noise and lack clarity. But for casual projects, headphone mics may provide just enough audio capture to get the job done [3].
Better microphone options
For higher quality audio recording and production, there are better options than plugging a microphone into the headphone jack. Some common upgraded microphones include:
- XLR microphones – These professional-grade mics require an audio interface or mixer to connect to a computer, but provide studio-quality audio. Popular XLR mics include the Shure SM58 and Audio-Technica AT2020.
- USB microphones – USB mics connect directly to a computer’s USB port for easy plug-and-play functionality. Well-reviewed USB options include the Blue Yeti and Razer Seiren Pro (https://www.pcgamer.com/best-microphone-gaming-streaming/).
- Lapel mics – These clip-on mics attach to clothing near the mouth and work well for podcasts, voiceovers, and interviews. Good budget lapel mics are the PowerDeWise and Purple Panda.
The best microphone depends on the intended application. For streaming, the Blue Yeti or Razer Seiren Pro are solid choices. Music vocalists may prefer an XLR mic like the Shure SM58 for studio-quality recordings. Lapel mics excel for on-the-go recordings like interviews or podcasts.
Upgrading to a dedicated external microphone can drastically improve audio quality compared to using a headphone jack. Take time to research which type of mic suits your needs.
Summary
To recap the key points, microphones and headphones use different jacks due to differences in their wiring and audio signal levels. While you can physically plug a microphone into a headphone jack using an adapter, this setup comes with limitations for audio recording quality and volume levels.
Using a headphone jack for a microphone can work sufficiently in some basic voice call or speech-to-text situations where audio clarity is not critical. However, the microphone input on proper audio interfaces will always provide superior quality and control.
For any important audio recording, podcasting, or other production use, it is best to connect your microphone directly to a dedicated external audio interface, USB microphone, or other equipment with a proper mic input. The microphone jack and associated recording features will ensure you capture high-quality audio and allow for proper gain staging.
In summary, adaptors can allow a microphone to work through a headphone jack in a pinch, but for the best results, it is recommended to use recording equipment with mic-level inputs designed for microphones.