What is a Condenser Microphone?

In the realm of microphones, there are basically two types everyone should know: dynamic and condenser mics. Dynamic and condenser microphones serve similar purposes when it comes to recording sounds, but their most crucial differences lay in what settings they’re most suited for. 

In simpler terms, dynamic microphones are more suited for live performances where volume levels are higher and there’s a lot more background noise. Condenser microphones, on the other hand, are used to pick up detailed sound in an environment where audio can be tightly controlled like a recording studio.

If you’re someone who’s looking to understand the distinctions between different types of microphones, what is a condenser microphone specifically, how a condenser microphone works, and how you can most effectively record with types of condenser microphones, then this is the know-all guide for you.

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What is a Condenser Microphone?

A condenser microphone is a recording device that’s built to pick up sounds and delicate noises in a controlled setting and in situations where details, fast transients, and accuracy are more important, like for recording vocals, acoustic guitars, drum overheads, bass guitar, and brass instruments. Because of their lightweight membrane, condenser mics are more sensitive to sound.

Most condenser microphones, if not all of them, are not suited for noisy settings where there are a lot of loud sounds happening at once, as condenser microphones are created to pick up detailed sounds. Condenser microphones are often chosen for their wide frequency responses, high-sensitivities, superior transient response, and overall sound quality.

Condenser microphones are very important for properly recording vocal audio for films, music production, and the like, and are the best option to go for in a quiet room. Using a condenser microphone will help you pick up and reproduce the sound waves more naturally.

How Do Condenser Microphones Work?

Now that you know the basic answer to the question “what is a condenser microphone?” you can now move on to asking “how does a condenser microphone work?”

Like all microphones, condenser microphones are transducers that work to convert mechanical wave energy (sound waves) into electrical energy (audio signals) and are often connected to an external power source. One of the most important parts of the condenser microphone is the diaphragm, which is a thin movable membrane connected to the mic capsule around its perimeter. It moves according to the sound pressure difference between its front side and backside and moves in accordance with the sound waves it is subjected to, making this an essential part of the condenser microphone transducer.

Condenser mic capsules are designed as parallel-plate capacitors, with the movable diaphragm acting as the front plate in the capacitor while the backplate is stationary. When sound waves hit the diaphragm, the diaphragm vibrates in close proximity to the backplate. The condenser capsule must be charged to function properly, or in other words, the condenser capsule has to hold a fixed charge to stop the drainage of electrical charge. This is why all condenser mics require power to work and why the capsules have a very high impedance converter.

This charge, or polarization voltage, is supplied either externally through a powering method or internally via electret material placed inside the capsule. External power condenser mics get their charge from phantom power, external PSUs, T-power, batteries, or another powering method. Phantom power however is probably the most popular and safe way to power condenser microphones, as phantom power methods, or external power, power condenser microphones directly and is used primarily to power studio and film condenser microphones. Electret condenser mics on the other hand are pre-polarized with quasi-permanently charged electret material.

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Differences Between Condenser Microphones and Dynamic Microphones

When you’re considering a dynamic microphone versus a condenser microphone, it’s important to consider what your recording environment will be like. Recording live music at a concert will require different specifics from your microphone and is where dynamic mics work best.

Because condenser microphones are so sensitive to different sounds, they’re not ideal for use in places with a lot of background noise. That’s why they’re most often found in studio spaces or other quiet environments. Similarly, using a dynamic mic in a studio setting won’t do much for sound quality either.

You may want to consider using a condenser microphone if you’re recording acoustic music in a quieter environment. Because acoustic instruments like bass, drums, acoustic guitar, and others have a more precise sound, a condenser microphone can help record it more naturally rather than a dynamic microphone.

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Types of Condenser Microphones You Should Know

Now that you understand condenser microphones’ inner workings, we can move on to learning what condenser microphone is best suited for your needs. When using your condenser microphone, ensure that it is set up properly. Make sure that your condenser mic is connected to a power source, and set up your microphone so it’s directed towards the source of the sound you’re trying to record. If your condenser microphone is a USB microphone, make sure that the software associated with it is properly installed.

When shopping for condenser microphones, it is common to hear the terms “small diaphragm”, and “large diaphragm. If the movement of a flexible diaphragm in a condenser microphone creates the electrical signal that we record, then the size of the diaphragm affects how it responds to sound waves and picks up audio signals.

In simpler terms, small diaphragm microphones are much thinner, smaller, end-fired, and pencil-shaped, whereas large diaphragm condenser microphones are bigger and side-addressed. Both of these condenser microphone types also have specific uses in the studio for capturing the best audio.

Large Diaphragm Condenser Microphone

In general, large-diaphragm microphones are used to record vocals, ensembles, acoustic guitars, and pianos. A large-diaphragm mic is also great for micing a “room” to better pick up the ambiance. 

Because they’re more sensitive to sound pressure, condenser microphones are better at picking up details. One such example, and perhaps the most important one, is for vocals. 

While it’s possible to use ribbon microphones or dynamic microphones for recording vocals, a condenser mic is the best option for vocals, especially the larger diaphragm condenser mic. The reason for this is that it records details, nuances, and intricacies of the singer’s voice, and it is also better at picking up the low-end frequencies.

Other instruments that large-diaphragm microphones capture best are acoustic bass, bass guitar, saxophones, trumpet, and piano.

Small Diaphragm Condenser Microphones

Small diaphragm microphones are generally used exclusively for instruments, like close-micing an acoustic instrument, overheads for drums, and horn sections.

Small diaphragm condenser mics are the best to go for when recording instruments like the acoustic guitar. If you’re trying to capture the way the acoustic guitar sounds naturally, then the small-diaphragm condenser microphone is probably a good choice. The reason for this has to do with the superior transient response, with small-diaphragm mics being more capable of picking up details in a way that doesn’t electronically change the sound, making it a great choice for acoustic guitars. 

A small-diaphragm condenser mic with an omnidirectional polar pattern is your best bet when capturing the sound of an acoustic instrument in a larger performance. However, if you’re recording a solo, then a large-diaphragm condenser mic will work better.

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Final Note

Learning the answer to the question “what is a condenser microphone?” is surprisingly complex, but every detail allows us to know exactly what kind of condenser microphone we need for specific occasions. From small diaphragm condenser microphones to large diaphragm condenser microphones and even a few others in between, we can figure out what brings out the best sound in our recordings.