We all use microphones on a daily basis. whether you’re making a call on your phone, using your headset to chat in a zoom meeting, recording a podcast, or just recording something with audio.
but have you ever stopped and marveled at this technological marvel? maybe you’re thinking about upgrading your computer and have reached the point where you really need to understand what you’re working with.
Reading: Are headphone input or output
To really understand how an average microphone works, you need to understand the flow of the audio.
When you work with audio on a daily basis (or are just curious), you need to have a good understanding of the input and output systems of your devices.
is it a microphone input or output?
a microphone is an input device. this means that it “takes” audio information and sends (or inputs) it to its receiving device. it could be your computer, phone, or someone else’s device. when you use a headset, you are using an input/output device as it can receive and play audio.
what is the difference between an input and output device?
the difference between an input and output device lies in its function. input devices receive and transfer information to a device for processing. output devices can interpret and play that captured audio. These days, most general devices have I/O capabilities, e.g. a phone or laptop, while specialized equipment focuses on one function.
Think of it this way: An input device takes “input” information and sends it to a processor which then sends this information to an output device which pumps the audio “out” by playing the processed information.
Input devices are designed to allow only information/audio/data input, while output devices can only play that information.
if you have a dedicated input device like a recording microphone, then you won’t be able to output the information you receive.
you would need a separate device for that. if you have a dedicated output device, such as a large set of speakers, they will only output the audio they receive.
However, there are devices that can receive input and produce an output. these are generally known as I/O (input/output) devices.
Your computer and your phone are two of the most common I/O devices on the market. There are also many applications that have made I/O conversion easy and very useful, such as text-to-speech software.
you speak, the computer receives the audio through its input microphones and, through software, translates the processed data into text.
Other functions of I/O devices are:
- receive an email and be able to send it to the printer for printing.
- press the keys on the keyboard and see the text displayed on the screen.
- take a photo on your phone, the camera is the input device and the phone screen is the output device. the list is endless.
examples of input devices
the actual input device is a piece of hardware. the hardware input device receives data from an external source and has the ability to process and send that data to another device. this external input is sent to the internal processor and converted to raw data. this data must be sent to an external processor before it can be interpreted by an output device.
The most common examples of input devices are:
- the computer mouse – the computer relies on the user to move the mouse, to generate spatial data. the mouse cannot move on its own, which means it is an input device.
- the keyboard: the keyboard accepts user input (what keys you press) and sends that input to the computer for its processing and output. it cannot receive information or do anything with it.
- the webcam: the webcam takes the image it receives and sends it to the computer. the webcam can’t output anything like a projector, just like a projector can’t output sound unless it has built-in speakers, however it would be better to use external speakers, please refer to my other post on how to connect bluetooth speaker to projector.
- the microphone – external sound is an input source that is received by the microphone and processed by the controller. the computer then interprets that data by saving it as a file or sending it to an output device.
examples of output devices
Output devices are pieces of hardware that have the ability to output information in a form that we can interpret. the output can be in the form of text, images or audio. receives data from a source and can display or replicate that data in the form it was originally received.
The most common examples of output devices are:
- your computer monitor: Your display receives data from your computer and then displays it as text, images, or video on the screen. it does not receive raw external data and cannot transfer data.
- a projector: When the projector receives data from the computer, it can display it visually. it can’t receive external data or send data to something else.
- speakers: When the speakers receive audio data, they can interpret it and convert it into sound. it cannot receive any sound like a microphone, but simply outputs what it received from the audio device.
- headphones: Similar to speakers, your headphones receive audio data and convert it back to sound. your headphone speakers can’t take raw sound from outside and send it back to your computer. for that, you need an input device added to the headset, like a microphone.
why are microphones considered input devices?
The main function of a microphone is to convert sound waves into electrical signals through an acoustic-to-electric transducer. these electrical signals are then converted into digital audio data, which is then sent (or input) to a computer.
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For a microphone to truly be an input device, it must be able to capture and send audio signals to a computer (or phone, or any other device).
This is typically done by converting analog audio signals (ac voltage) into digital data compatible with a computer.
There are a few ways that microphones can be connected to a computer that will allow for analog to digital conversion. each method has its own advantages and disadvantages:
- Digital Microphone: Better known as a USB microphone, digital microphones have built-in ADCs and convert sound into digital data directly. the usb connection connects directly to the computer.
one of the most popular examples of a usb microphone on the market has to be the blue yeti (amazon link).
most people, myself included, use it as a microphone for conference calls, a home recording studio, think podcasts, and even gaming thanks to its supreme sound quality.
blue yeti usb microphone
benefits: the blue yeti is probably the best on the market and because there is a direct usb connection the sound is excellent.
Drawbacks: Fine-tuning must be done on the computer, which means you don’t have as much control.
- audio interface (hub): Next, for those who want to go a step further or perhaps already have a microphone, is the hub-style audio interface. probably the best after a full-fledged study. This powerhouse allows for multiple microphone connections (depending on the design), meaning you can record yourself singing and playing an instrument with a dedicated microphone for each audio input. there are also multiple customizations that can be done directly in the interface to get the best audio recording. the audio data is then sent to the computer via usb, lightning, firewire, thunderbolt, etc.
There are several great audio interfaces available, but I really like the focusrite scarlett 2i2 audio interface (amazon link) for its features and sleek design.
The lightweight design also means it’s not the worst thing to take with you if you need to travel.
focusrite scarlett 2i2 audio interface
advantages: An audio interface is typically used in a small-scale recording studio. offers excellent customization features and excellent sound quality.
cons: you will need a separate microphone.
- audio interface (adapter): Although most won’t choose this as their primary audio interface, it’s a great mobile option. it usually only comes with an input (for the microphone), a basic converter, and a computer connection port (usually usb).
This option is great if you’re short on cash or just want something you can easily take with you.
I like shure x2u (amazon link) because it’s a powerful tool that hasn’t let me down yet.
advantages: Similar to the function of the larger audio interface hub, the adapter is easier to carry and has plug and play functionality. perfect for recording artists to have as a hidden backup in their purse.
Drawbacks: You still need a separate microphone, and while the sound quality is excellent for an adapter, it will never be an audio interface hub.
this just goes to show that while a microphone can be seen as an input device, it still needs to be able to send that data to the computer to be useful. how you choose to send that data will determine the overall quality of the sound.
can a device have input and output at the same time?
So far, we’ve discussed input and output devices separately, and rightly so, because for the most part, they’re separate. a device can be both an input and an output device, but can any device be an input and output device at the same time? The answer is yes.
For a device to have both functions, it must be able to receive raw data from an external source or other device (input), as well as send data.
here are some examples of input/output devices we use on a daily basis:
- the usb flash drive: capable of receiving, saving and transferring data, the usb flash drive is the perfect example. when it receives data, it is an input device and when we retrieve data from it, it becomes an output device.
- a rewritable cd or dvd drive: we can send data easily to these devices and retrieve it again.
Are headphones with a built-in microphone both input and output?
so if devices like cd’s and usb flash drives are input and output simultaneously, where does that leave something like a headset with a built in microphone?
Headphones designed to listen to audio are output devices. however, when you add a microphone, it takes on the role of an input device. that means it has input and output capabilities. while the speakers are separate from the microphone, the dual function is connected to one device.
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thus, although the first headphones began with humble beginnings as output devices only, modern developments have provided us with headphones that can now receive input and deliver an output.
Usually the output will be alternate audio signals (like when you’re chatting with a friend or playing an online game with chat).
Are headphones without a built-in microphone input or output devices?
so do headphones without a built-in mic have any input functionality? just think about it, we’ve all had those stinky airplane headphones, and yeah, the first time I took a flight, I thought I’d bring them (don’t judge me).
however, you soon realize that 1) the connector is weird and 2) you can’t use them to chat, they don’t have input functionality.
a set of headphones without a microphone are just output devices. they receive audio signals from a computer source and send them to your ears. because of the way they are designed, they cannot take any input from the outside and convert it into electrical signals.
However, there is a trick you could use to turn your speakers (headphone speakers can be a bit tricky, but who knows) into a microphone…just don’t try this with your best speakers.
can I use a speaker as a microphone?
If you want to turn your speakers into a microphone, technically you can. It’s not for the technically challenged, but heck, if it’s an old pair of speakers and you’re just messing around, why not give it a try? To give you a general idea of how this works, consider the following:
Your speakers have a cone that vibrates to create sound. it is similar to the diaphragm of the microphone that vibrates when it receives sound and those vibrations are converted into electrical signals. By reversing the function of the speaker cone, you can create a speaker microphone that will receive external audio.
You might be wondering how the heck that would work. well, quite simple actually.
Although speakers and microphones look very different (all in the attempt to capture and produce great sound), the inner workings (along with a bit of trickery in the cabling) can give you the same results.
if you’re dying to try it, follow these instructions:
What you’ll need to use a speaker as a microphone:
- an old microphone (broken is fine)
- a wire cutter
- electrical tape
- an amplifier (working)
- a speaker
Step-by-step guide on how to use a speaker as a microphone:
- start by cutting the actual microphone from the cable; you just need the cable with the output connector on the other end.
- strip the cable a bit to expose the wires. you will see three internal wires.
- completely remove the protective cover from the red and black wires (about half an inch is fine). add some electrical tape to the white wire as you won’t need it.
- remove the actual speaker from the protective box.
- you will see two pins on the speaker, the left one is usually the positive terminal and the right negative.
- Using pliers, connect the red wire to the positive terminal and the black wire goes to the negative terminal.
- Plug your output jack into the amp and test your new microphone!
can microphones be used as speakers?
If it’s possible to turn a speaker into a microphone, what’s stopping us from turning a microphone into a speaker? nothing really, but the output (due to the size of the mechanics in a mic) might not be worth the effort. and believe me, there is a little more effort.
While microphones and speakers are similar, they have reverse functionality, and microphones are a bit more complex, literally needing to collect raw external data and convert it into electrical signals. So how do we give speakers this superpower?
the easiest way is to reverse the signal flow. you would need a speaker cable connected to the microphone and a converter.
If the microphone uses a condenser, you will also need to ensure that a constant biased charge is maintained on the diaphragm. the tape dynamics are not the best to try this experiment as they are quite sensitive.
Overall, I’d probably suggest you don’t try this at home. the chances of failure are quite high.
so while your microphone can technically be used as an output device, it won’t blow your mind and it won’t be the easiest of weekend projects.
Microphones are input devices. they receive external sound and convert it into electrical signals that can be sent through a computer to an output device. the output device can either play that sound or convert it to something else, like text.
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