Every audiophile knows that condenser microphones are very good at capturing sound, but this high sensitivity can also be bad in specific scenarios.
Condenser mics are so sensitive at times that they even pick up all sorts of unwanted background noise, such as a person talking in the background or dogs barking outside. This begs the question, why are condenser microphones more sensitive than other types of microphones such as dynamic mics in the first place?
Condenser mics are more sensitive due to an especially low mass diaphragm being used inside, and this membrane is near a charged plate.
Therefore the diaphragm of the condenser mic follows changes according to the rhythm of sound waves with more accuracy than other mics such as dynamic mics and is more sensitive.
Dynamic microphones have a relatively heavier wire coil inside instead of a lightweight membrane, and this coil is substantially more challenging to move by the same sound waves. Therefore dynamic mics are far less sensitive to some sounds than condenser mics.
This article will provide a more in-depth answer to why condenser microphones are more sensitive and how you could make them less susceptible if you ever needed to.
How Do Condenser Microphones Work?
To fully answer the question, why are condenser microphones more sensitive than other types of mics? We need first to understand how they work and what they are designed for.
Condenser mics are also commonly referred to as capacitor mics by many. This is because their design philosophy resembles the kind of setup you would find in a capacitor.
Capacitors are two electrically charged metal plates placed near each other, and the value of its capacitance changes as the distance between the plates changes.
Similarly, in a condenser mic capsule, you can find a charged metal plate near an extremely light and thin plastic diaphragm coated with a metal such as nickel or gold.
Electricity is passed through both the diaphragm and the metal plate by an external power source. This creates a capacitor-like setup. Sound waves that hit the diaphragm cause it to vibrate back and forth relative to the metal plate. This vibration leads to variation in the charge across the plate.
This changing current is then transferred to a recording device or mixer via cables and is converted back into sound by another transducer.
Why Are Condenser Microphones More Sensitive?
Here are two reasons why Condenser Microphones are more sensitive:
1. Condenser mics utilize a diaphragm of low mass and have the charged metal plate nearby
The main advantage of condenser microphones over other types is that these mics capture much more detail and are highly sensitive. But why are condenser microphones more sensitive? This is because condenser mics utilize a diaphragm of low mass and have the charged metal plate nearby.
Due to requiring less energy to move the lightweight diaphragm, these mics can preserve and capture high-frequency audio with ease. This higher dynamic range and enhanced high-frequency response make condenser mics the mics of choice for professional studio recordings.
2. Condenser mics are commonly used to capture audio containing vocals, guitars, pianos, and strings
Nonetheless, condenser mics are still not as robust as dynamic mics and are pretty fragile. Many condenser mics cannot handle the sound pressure levels you usually see being used on dynamic mics and could be damaged after exposure to such groups.
The biggest problem is that the condenser mic, due to being highly sensitive, often captures unwanted ambient background noise, which is never ideal. They require the use of proper sound-treated rooms and are never the mic of choice for live performances due to this reason.
How To Make Condenser Microphones Less Sensitive?
Condenser microphones are considered the ideal mics to record audio in, but what if the space you’re using it in is full of background noise, and you end up getting poor quality audio. Wouldn’t it be fantastic if you could decrease the microphone’s sensitivity and prevent unwanted noise from creeping into your recordings?
There is no direct method to make condensers less sensitive because they are just doing what they are designed to do -capture all sound in extra detail.
Experimenting with volume won’t help either because the microphone will still capture all the lower or higher volume sounds. But there are still some things you could try to help your mic pick up the sound you want and ignore the rest.
You could make your condenser microphone less sensitive by:
- Reducing the distance between the primary source of sound and the microphone.
- Soundproofing your room to block out noise from the outside.
- Setting up preamp and gains to proper levels.
- Installing sound gates and pop filters.
- Software editing to remove unwanted ambient noise.
A Less Sensitive Alternative
If you’re planning on using a microphone in a place where it’s not possible to eliminate all background noise, then you might have to consider using a dynamic mic instead.
Dynamic microphones have a diaphragm attached to a wire coil placed inside the field of a magnet. When sound hits this diaphragm, it moves the metal coil of wire with it and produces a varying AC according to the pattern of the sound wave. This is how sound is transduced into electrical current, which is then sent to the amp or mixer via cables and is processed.
Due to their construction, dynamic mics are incredibly robust. These are the mics of choice in noisy environments such as a live stage performance due to their low susceptibility to feedback and ability to withstand high volumes.
However, the relatively heavy coil of wire requires more energy to vibrate and moves slower than condenser microphones. This construction of dynamic mics means that these microphones are less sensitive than condensers, especially at higher frequencies.
Additionally, audio with fast transients can end up losing significant definition when recorded with dynamic microphones.