What is a condenser microphone?

These days anyone can pick up a phone and record themselves singing for fun.

So many electronics have small microphones that are consistently being improved with each new smartphone or laptop model.

However, if you are considering dabbling in professional recording, you need to be prepared with a good microphone.

Condenser microphones have been a favorite option among professionals for years and years. A condenser microphone has a long history as the optimal microphone for recording studios.

How does a Condenser Microphone Work?

A condenser microphone is also known as a capacitor microphone.

When these microphones were first invented in 1916, this name referred to the similarity between this microphone and a capacitor.

A capacitor works when you place two electrically charged metal plates close together. So the basic design of a condenser microphone is similar to a capacitor.

Basic Construction

Most condenser microphones are constructed with a thin membrane situated near a solid metal plate. Today, pretty much all condenser microphones use gold-sputtered mylar for this metal plate. It requires a metal like gold-sputtered mylar that will efficiently conduct electricity. Both the membrane and the metal plate together make up the capsule of a condenser microphone.

Converting Sound into an Electrical Signal

The solid metal plate, or backplate, is fixed, but the membrane, or diaphragm, is movable. Sound changes into an electrical signal when sound waves hit the membrane and then move back and forth in relation to that metal plate. This vibration is known by a fancy term -capacitance. Capacitance essentially means that sound is converted into an electrical signal that can be recorded.

The two delicate plates of a condenser microphone make it sensitive to the slightest sounds. This sensitivity makes it an excellent choice for recording studios over other types of microphones. It will pick up a wide range of frequencies accurately.

Powering the Microphone

All condenser microphones need a source of external power to charge the plates. The charge between the microphone plates does not create a voltage. However, voltage is necessary to boost the electrical signal to the speakers.

The international standard is to use the phantom power offered by most modern condenser microphones. Neumann invented this phantom power, which is essentially an electric current sent down the microphone cable. You might see it referenced as 48V Phantom Power because it usually uses a 48-volt signal.

Most modern condenser microphones are also powered by a battery. This option requires other components and usually not the only thing powering a condenser microphone in a recording studio.

Finally, older microphones used tube technology for power before the invention of phantom power. Some people believe there is a big difference in the sound of a tube condenser microphone. The tubes used in these older condenser models were the only power source to boost the signal for recording or broadcasting purposes.

Types of Condenser Microphones

A condenser microphone does not vary much from one to another. As mentioned before, most modern condenser microphones use gold-sputtered mylar, but some older models might use another metal for the diaphragm. Otherwise, the two main types of condenser microphones depend on the size of the diaphragm.

Large-Diaphragm Condenser Microphone

A large-diaphragm microphone usually means that the capsule’s diaphragm is 1 inch or larger in diameter. In regards to their typical design, a large-diaphragm microphone is much bigger and operates to the side.

This type of condenser microphone was developed first. Certain parts used to construct them were incredibly noisy, which meant the microphone needed to have a large diaphragm to pick up the right sounds.

Small-Diaphragm Condenser Microphone

A small-diaphragm microphone usually refers to a diaphragm that is ½ inch or less in size. However, some condenser microphones that have small diaphragms might have slightly larger capsules. This type of condenser microphone is often seen with a slim design. They are typically operated as end-fired, as opposed to larger-diaphragm microphones.

Small-diaphragm condenser microphones came into existence in the 1960s and 1970s. By then, technological advancements in the sound recording industry provided the right tools to make a smaller model possible. These advancements included low noise transistors that didn’t give off too much ambient noise.


There are several advantages to condenser microphones based on their construction. Some of these advantages make them well-suited to sensitive recording jobs.

  • A Light Diaphragm Assembly
  • Extended Frequency Ranges
  • Come in Smaller Designs

Condenser microphones have light, easy to move diaphragms thanks to their construction. Their light assembly also makes them perfect for even capturing high-frequency ranges. They provide sound quality that is superior to other microphones because the diaphragm is so weightless.

A condenser microphone is the best option when you want to get a flat frequency response or need extended frequency ranges. Plus, condenser microphones have an excellent transient response. It can pick up fast bursts of sound energy like the rat-tat-tat of a drum or the quick plucking of a guitar’s strings.

And, considering the small-diaphragm options, condenser microphones can be smaller than other types of microphones available. This might not be as important in a recording studio, but it can work in your favor if you want a condenser microphone for personal use.


There are several disadvantages that don’t make condenser microphones ideal for certain activities. In general, condenser microphones are not the best choice for a busy, active stage.

  • Limits to Signal Level
  • Cheap Equals Noise
  • Complex & Delicate Construction

Condenser microphones have limits when it comes to the maximum signal level they can take in at one time. You need to be careful to avoid distortion in sound if you reach the uppermost signal level.

You can shop around if you are in the market for a condenser microphone, but beware that cheaper models sometimes mean less quality. You might notice a lot of sound coming from the electronics on a cheap condenser microphone. Plus, these less expensive models do not offer the superior sound quality of an upper-range model.

Finally, you need to always be wary of changing conditions when it comes to condenser microphones. They are made using complex parts, which can be sensitive to extreme temperature or humidity changes. You might notice that the sound quality is adversely affected if it is allowed to get too warm, cold, or accumulate moisture.

What do you Use Condenser Microphones For?

For the most part, most condenser microphones will be found in recording studios. They produce such fine sound quality due to their sensitivity. However, small and large-diaphragm models are used for slightly different purposes.

A large-diaphragm condenser microphone is an optimal microphone for vocal recording. It can also record musical instruments with low-end sound. Keep in mind that microphones with large diaphragms are sensitive to any little sound. You need a pop filter to accompany a large-diaphragm model because it filters out little noises and feedback that you don’t want to hear in a playback. Every small breath or pop of air will be picked up by the sensitive diaphragm.

You should pick a small-diaphragm condenser microphone in situations when you need to record a broader frequency response. Most instruments, including cellos and guitars, are better matched with a small-diaphragm microphone.

One place you will not see a condenser microphone is a stage. For the most part, performers need a more rugged option than a condenser microphone. Condenser microphones are better suited to situations where they can be stabilized in one place, usually with a filter to capture unwanted breaths and pops.

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