How Do Microphones And Speakers Work?

Have you ever wondered how microphones take in sound and play it through larger speakers to an audience? A lot of interesting stuff goes on in a blink of an eye when your mic and speaker setup converts sound into electrical signals and back into sound for an audience to hear.

Microphones capture sound waves and convert them into electrical signals through a sensitive coil in a magnetic field. Speakers do the opposite and convert electrical signals into sound waves through a large cone attached to a coil surrounded by a magnetic field.

In this article, I’ll break down the inner workings of microphones and speakers. I’ll follow the sound trail throughout your entire setup — from the moment your voice gets picked up by your microphone to its journey through the preamplifier, amplifier, and finally, into the output speakers.

Microphones and Speakers Explained

The ability to translate sound into electrical signals and back again is truly remarkable. Whether you’re talking on the phone, playing your favorite music in your car, creating music for your next album, or watching a movie on your laptop, you’re using microphones and speakers to make it all happen.

Both mics and speakers are necessities in a home studio. However, their applications are not limited here – you can find mics and speakers integrated into a single device, such as gaming headphones and police radios.

Microphones and speakers work together to record and play music, although separate technologies go into the development of each device. Microphones capture sound waves from different directions (based on the polar pattern) and convert them into electrical signals. Speakers then take those electrical signals and turn them back into sound waves that an audience can hear.

Below, I’ve stripped down the essential components of both speakers and microphones:

How Microphones Work

A microphone is a transducer that converts sound energy into electrical energy. Microphones are considered a vital determinant of the resulting sound quality. If your mic is poor quality, worn out, and damaged to the extent of producing harsh or distorted signals, that’s what you’ll get in the end speaker output. 

Audio interfaces and DAW software can help eliminate some noise, but this can be difficult to achieve. As such, it is important to focus on getting a clean signal from your microphone in the first place.

To understand how a microphone works, we need to understand its various components. An average microphone consists of the following parts.

• A voice coil: Often made of copper or aluminum wire wound around a bobbin. When vibrated, it creates disturbances in the magnetic field.
• A permanent magnet: Creates a permanent magnetic field around the voice coil.
• A diaphragm: Receives sound and vibrates in a manner that corresponds to the speaker’s voice.
• Signal-carrying wires or transmitter: The electrical signals created by the movement of the voice coil around a permanent magnet are transmitted to the next processing phase by wires or sent to a receiver by a wireless transmitter.
• Other connections: Modern microphones offer a wide variety of connectors that allow you to connect your device to an amplifier, receiver, or computer. USB is one of the most popular connectors for home studio mics since it allows you to connect directly to the computer.

When you speak directly into the microphone, your voice changes the sound pressure, which moves the diaphragm attached to the voice coil. As the voice coil vibrates inside the magnetic field of the permanent magnet, it creates an electrical signal that matches your voice. The signal generated will vary according to the mic’s component quality.

The signal-carrying wires (usually XLR cables) carry the resulting signal to the amplification stage. Some microphones have a wireless transmitter that sends these signals wirelessly to a receiver located a couple of feet within the room.

That said, all microphones sound different due to their size and quality differences. Different microphones contain different transducer technologies, giving your mic unique sound properties. Also, the speaker’s unique voice contributes to the differences in microphones.

If you want to know more about how microphones work, you can check out this video.

When buying a microphone, ensure it can handle the sound pressure levels you’ll be recording or playing at to avoid unwanted distortion. An ideal microphone for your studio should also be adorned with the right features, such as noise cancellation, preferable pickup patterns, and high-quality audio.

With the rapid expansion of technology, there are many models of microphones that serve different purposes. For example, you can opt for wired microphones or wireless microphones based on your needs.

Choosing your ideal microphone is half the battle — with the right microphone, you can get the best possible quality input for the rest of the system to process. The next challenge is getting your speakers to produce an output that’s as identical to the input as possible, with as little noise as possible.

How Speakers Work

Like microphones, speakers are transducers, but in this case, they convert electrical energy into sound energy. Speakers take in an amplified signal and pass it through a voice coil to create sound.

To better understand how speakers work, let’s dive into the basic structure of a speaker:

• Speaker cone: Vibrates to create sound.
• Voice coil: The electromagnet attached to the diaphragm.
• Spider: Flexible mechanism that restores the voice coil to its original position between movements.
• Dust cap: Located at the center of the diaphragm, protecting it from dust.
• Permanent magnet: Creates a permanent magnetic field around the voice coil.
• Enclosure: Every speaker comes in an enclosure made of wood or plastic to prevent sound loss from wave cancellation.

Here’s a breakdown of how speakers convert electrical signals into sound waves.

• First, the mic-level signal goes into a preamp, where a series of transistors and vacuum tubes raise its voltage to a line-level signal. Preamps also add noise and distortion to the signal.
• The now powerful line-level signal travels to an audio interface, where it’s fed into your computer for processing. In this stage, you can add EQ, distortion, reverb, and echo through a digital audio workstation or other editing software.
• The edited soundtrack can be channeled to an amplifier through a quarter-inch (6.35 mm) jack. Unfortunately, most audio interfaces do not have an integrated amplifier. You need an external amplifier to boost the signal to a more powerful voltage that a speaker can play.
• The analog signal goes through your speaker’s voice coil, which turns into an electromagnet. The electromagnet moves back and forth within the permanent magnet surrounding it. Since the voice coil is attached to a diaphragm, both move at the same velocity, pushing the air around the diaphragm and creating sound.

As you may have guessed, several other components come into play before the sound gets to the speaker cone and is disbursed to the audience. Some of these components include:

• Preamplifier
• Amplifier
• Audio interface
• DAW and other editing software

Preamplifier

The mic signal is one of the weakest signals. It cannot drive a speaker on its own without being amplified. Microphone preamps can exist as standalone units, although they usually exist as elements of a much larger system, e.g., a mixer.

Amplifier

An amplifier’s main duty is to convert a line-level signal to a speaker-level signal or the more powerful signal that can actually drive a speaker. Amplifiers come in all shapes and sizes, with the most powerful ones putting out over 2000 watts per channel.

Amplifiers can also exist as standalone units (external amps), while others can be part of your receiver or mixer. Other types of amplifiers can also exist as software that can be downloaded and used on your computer.

Audio Interface

An audio interface is another must-have piece of equipment in your studio setup. Audio interfaces provide all the ports you need to hook up your hardware and instruments to your computer. However, its most important role is converting input into a format your computer can understand. A digital-to-analog converter or DAC helps in this task. 

A digital-to-analog converter is a device that takes the soundtrack that’s processed and stored in binary in your computer and converts them into an analog waveform that a speaker can play. Audio interfaces are said to have much more processing power than your computer’s internal sound card.

Check out: What is an Audio Interface?

How Different Types of Microphones Work

No mic sounds the same as the other because they all come with different designs, components, and capabilities. The most popular microphones are dynamic, condenser, and ribbon microphones.

1. Dynamic Microphones

Dynamic microphones feature a rather simple design, with a voice coil suspended in a magnetic field, just like an average speaker. As sound hits the diaphragm, the mic’s voice coil captures it and sends it to the next stage.

Dynamic mics have wide applications in live performances and recording instruments in your home studio. They’re less sensitive than the condenser type. They also need no external power to operate.

One of the most popular dynamic mics is the Shure SM57 Dynamic Microphone (available on Amazon.com), which promises a world of versatility and quality audio for both home and professional studio applications. Its greatest strength is its ability to accurately capture instruments with minimal distortion and background noise.

Last update on 2024-07-03 / Affiliate links / Images from Amazon Product Advertising API

2. Condenser Microphones

Condenser microphones (also known as capacitor microphones) use a different kind of transducer to convert sound into electrical signals. Instead of a diaphragm and voice coil setup, they have two charged plates that move closer to or further apart, changing the circuit’s capacitance. To capture sound, condenser mics must maintain the charge on the two plates, which they achieve through phantom power or batteries.

If you record vocals a lot in your home studio, chances are, you’ve come across a condenser mic like the Rode NT1 (available on Amazon.com). This microphone yields clear, crisp vocals across the low, mid, and high-frequency ranges with minimal background noise.

Last update on 2024-07-02 / Affiliate links / Images from Amazon Product Advertising API

3. Ribbon Microphones

The technology behind a ribbon mic isn’t something new. These mics use an electrically conductive metal ribbon held by minimal tension to pick up sound. Like in dynamic microphones, the ribbon is also surrounded by a magnetic field. 

When sound strikes the usually corrugated ribbon inside the microphone, it picks up the movement of the air particles surrounding it. Ribbon microphones have a figure-8 pickup (bi-directional) pattern, which allows them to pick up sound from two directions.

Ribbon microphones like the Beyerdynamic M 160 (available on Amazon.com) record warm, natural sounds for broad applications in recording vocals and as overheads for your percussion instruments.

Last update on 2024-07-02 / Affiliate links / Images from Amazon Product Advertising API

Common Types of Speakers

Speakers can be classified by construction and the size of the driver (the component responsible for creating sound). How your speakers are constructed has a lot to say about the final output.

There are three popular types of speakers covering the full range of audio frequencies (low to high).

• Woofers: Are designed to produce low frequencies ranging from 50Hz-1000Hz. They draw more power from the amplifier than ordinary speakers. Larger amounts of power are required to move the massive speaker cone, which produces low-pitched sound.
• Mid-range speakers: These speakers produce lows that are not too low and highs that are not too high (between 250Hz-2000Hz). Mid-range speakers do not demand as much power as woofers, but they draw more from the amplifier than tweeter speakers.
• Tweeter speakers: Tweeters cover the highest frequencies that would be difficult to produce with larger speakers.

Another way to classify speakers is by the driver size; for instance, 6.5 or 6×9 speakers. Larger speakers are designed to take on the lower frequencies, while smaller ones produce higher frequencies.

A good speaker can make your music sound better and is essential for playing music. A good speaker is usually paired with a good amplifier and placed close to a wall or in an open space to deliver optimal sound.

Conclusion

That sums up how microphones and speakers work. If you’re starting your own home studio, it can be hard to know what to look for because you want to ensure the microphone or speaker you choose has the features you need and will last for years.

However, understanding how microphones and speakers work is invaluable in choosing the right ones for your home setup.