What Is a Condenser Microphone?

When it comes to recording audio, there are two types of microphones you can choose from—dynamic microphones and condenser microphones. Of course, both have their pros and cons.

However, in most instances, if it’s the professional, clean sound you’re looking for, a condenser microphone should be your first choice. That’s because condenser mics are excellent at picking up detailed sound in environments where audio can be tightly controlled (a studio, for example). On the other hand, dynamic microphones are often used in live settings where volume levels might be higher.

What Is a Condenser Microphone?

So, what is a condenser microphone? Condenser microphones are so-called because of the “capacitor” inside. This is the main operational component of condenser mics, and its primary purpose is to convert acoustic energy into an electrical signal. Just so you know, they’re called condensers because condenser is an old word for capacitor.

How Does a Condenser Microphone Work?

A condenser microphone is simply a specialized capacitor. So we’re on the same page, capacitors are an electrical component designed to store energy in an electric field temporarily.  They work by using two plates placed close together. The closer the plates are to each other, the higher the ability of the plates to store an electrical charge (capacitance). The capacitor is housed in a casing called a microphone capsule, and it can be seen when you remove the microphone grille.

In condenser microphones, one of the plates is made of an extremely light and thin material (usually gold-sputtered Mylar) that acts as the diaphragm. The other is made of solid brass and is called the backplate.

When struck by sound waves, the diaphragm vibrates, changing the distance between the two plates according to the rhythm of the signal. When this happens, the capacitance changes. This fluctuation in capacitance creates an electrical representation of the acoustic energy from the input source. Condenser mics use phantom power from external power supplies (usually 48V sent from the preamp). Because of this, you won’t need as much gain at the preamp to get the signal to a usable level.

The easiest way to understand condenser microphones is to picture them as magnifying glasses for sound. They pick up the minutest sound signals and reproduce a crisp, clean, clear sound output.

Common Types of Condenser Microphones

When you dive deeper into condenser microphones, you’ll discover that there are two main types—large diaphragm and small diaphragm condensers.

Large-Diaphragm Condensers

Large-diaphragm condensers are the ones you usually see in a studio setup. They’re so-called because they employ a diaphragm—over an inch in length. Because of their size, they’re usually mounted in a stationary position and are usually used from a side-facing position.

Condenser mics with large diaphragms are often used to pick up the richness and fullness of low-end sounds. Other advantages of large diaphragm mics include:

  • Lower self-noise. Air particles hitting a small diaphragm create higher pressure than when hitting a larger surface. As a result, small diaphragms produce more self-noise, while large diaphragms produce relatively little or no self-noise.
  • Low-frequency response. Because of its better sensitivity, a large-diaphragm microphone is better at capturing low-frequency audio signals.

Large-diaphragm condenser mics are best suited for (among other use cases) recording vocals, voice, and solo instruments. This is because they tend to make output sounds appear rich and vibrant.

Small Diaphragm Condenser

Small diaphragm condensers are sometimes referred to as pencil mics. This is because of the small thin design. The diaphragms on this type of condenser mic are usually less than an inch in length, and the diaphragm is configured in a front-facing position. Because of this, the audio source must be directed toward the top part of the mic.

Small diaphragm mics are excellent for picking up transients. They’re also great at picking up high-end sounds. Some significant advantages of small-diaphragm mics include:

  • Exceptional transient response. This means the small diaphragm can follow the sound waves more accurately.
  • Extended high-frequency response. Small diaphragm mics can pick up high sound, even beyond human hearing.
  • Consistent pickup pattern. Small diaphragm mics can accurately pick up sounds in the direction they’re pointed at.

If you’re looking for a more “natural” sound, a small diaphragm condenser mic would be your best bet. Examples of best use cases include recording acoustic instruments.

Need a Condenser Microphone?

If you’re on the hunt for a condenser microphone, make sure to browse our inventory of condenser mics and pick the one best suited to your needs. Alternatively, give us a call at 855-573-6683, and we’d be more than happy to advise on which condenser microphone is best for you.