Microphones 101: Electret Condenser vs. True Condenser

We’ve already talked about condenser microphones, their functionality, construction, impedance, and sensitivity, and what type of recordings and environment they are best used in. Since these mics use a capacitor capsule that needs to be charged, there was the problem of non-existent current, even though the voltage was high. Therefore, it was pretty difficult to find a compatible charge to push the signal out.

The answer was electret microphones and phantom power - a concept that removed the need for a PSU box for each microphone connected to the mixer. The phantom power generator was integrated into the mixer so that there was enough juice for any condenser connected. 

Then, in 1968, Sony invented a new type of microphone that carried standard P48 phantom power. And just like that, we’ve gotten ourselves an electret condenser vs. true condenser battle that still rages today.

How Do Electret Microphones Work?

An electret condenser microphone has a quasi-permanently biased condenser, meaning that the condenser capsules act as two capacitor plates placed parallel to each other that need a constant charge to function properly.

Those electret condenser capsules get their charges through a special material called an electret, a condenser element. An electret is something of an electrostatic counterpart to a permanent magnet, able to generate electric fields, both external and internal, and it has the ability to charge other components.

There are three different electret types of microphones:

1. Front-electret microphone - this type does not have a backplate, but the capsule is derived from the diaphragm and the inside surface of the capsule itself;
2. Back-electret microphone - the electret is stationed on the backplate, making it more durable and accurate than the front-electret models;
3. Foil-electret microphone - this is the most common type of electret microphone out there and the most affordable one. They use an electret film as a diaphragm instead of a specific plate coated in it.

True Condenser Microphones

There is not much to say about these mics, which we have not already covered in a previous article. These are traditional condenser microphones that use an externally biased condenser, meaning they get their power supply from an external source, usually located in the mixer they are connected to or from an external power box. 

Difference Between Condenser and Electret Microphones

It’s worth pointing out again that both are condenser microphones. The main difference is in the phantom power supply - while the true condensers get their P48 from an external source, the electrets have a power supply built into their capacitors that they use to charge and send the audio signal through the output into the system. 

The second difference is the electret material used to cover the diaphragm.

Another distinction between them is that the electret microphones are used in mobile devices like phones, laptops, and tablets, as they are easy to produce in high quantities for a low price, unlike true condensers, which are used specifically in studio microphones. 

The exception is gaming microphones, which have improved significantly over the years thanks to streamers. 

In the beginning, early electret models did sound different and worse in comparison to true condensers. Today, however, it is a different story. Around 95% of condenser microphones on the market are the electret types, and the sound difference is barely recognizable, if at all. Still, some companies choose to specialize in certain types of condensers. 

Neuman, one of the world leaders in audio technology, makes strictly true condensers. Their U87 model is still considered one of the greatest condenser microphones ever created and is widely used for studio recordings of vocals and instruments. 

Summary

When comparing the two types - electret microphone vs. true condenser microphone - is the sound difference recognizable? Both types of microphones can be and are used as mono and stereo microphones, both are more sensitive than the dynamic microphones, and both are used pretty widely across multiple industries.

You can say that in the end, it all comes down to preference. Some people believe that due to the production capacity and low cost of electrets, they are not of the same quality as true condensers. That might have been true in the early stages, but we don’t think that’s the case these days.

Although true condensers are widely recognized as the go-to microphones for the warmth and the sensitivity, the electret designs have significantly improved. If you don’t believe us, try them out for yourself. We guarantee that you will not be disappointed with the tone of the sound you recorded or its clarity or warmth.