Skip to content

Condenser Microphones

Condenser Microphones


One thing that really trips people up at home is the idea of the condenser microphone. People purchase large diaphragm condensers for their home recording because they are told they’re the best for tracking vocals, which is true. But a condenser mic is a lot more complicated than dynamic mics, as they require something that most novices and home recording enthusiasts are not aware of. Here, I’ll discuss the basic knowledge needed to benefit most from a condenser mic.

What is a condenser mic?

Why won’t it work when I plug it into my preamp?

What does “phantom power” mean?

How do I send phantom power to my mic?

Do all condensers need phantom power sent to them?

What is a condenser mic?
There are two basic types of condenser mics, large diaphragm, wherein the diaphragm is an inch or larger and the sound is captured from the side (examples, AKG 414, Neumann U67, Neumann U87), or a small diaphragm condenser, wherein the diaphragm is smaller than an inch, looks like a stick or pencil, and the sound is captured from the front (examples, Shure SM81, Neumann 184).

The diaphragm is made up of two parallel plates, like a capacitor.  Sound waves hit the front plate, which vibrates the space in between the plates, producing a signal that is sent to the mixing board.  Because these plates are thinner and lighter than the capsules in dynamic mics, they react to sound faster than dynamics, making them ideal for delicate acoustic sounds such as vocals, acoustic guitar, piano, etc. (as well as for cymbal mic’ing, drum overheads, room mics, etc.).

Why isn’t it picking up the signal when I plug it into my preamp?
The thing is, for a capacitor to work, it needs an outside energy source, such as a battery. Therefore, for your condenser microphone to work, it needs what is known as “phantom power.” This is unique to condenser microphones, as no other microphone requires phantom power.

Ok, but what does “phantom power” even mean?
The term “phantom power” refers back to a time when condenser mics each had their own power supply – and you can imagine how annoying it was on a big recording set up to have all these bulky electrical boxes sitting around the session. Eventually, engineers designed a way to send the power through the board, through the mic cable, and into the microphone, completely bypassing the need for an individual power box. All the boxes were gone, yet the mics still worked. Thus, the term “phantom power” was coined.

So, all condenser mics need phantom power? And how do I send it to the mic?
Some mics, such as Neumann U67s, still have their own power supplies, but for the most part, the mics you’ll be dealing with will need phantom.  Your board at home should have a phantom power button on it, commonly denoted as “+48V”.  Make sure, wherever it is (on the channel strip, on the back of the box, etc.), that the 48V option is selected.  Other mics dumb it down for you a bit, either by requiring only a battery for the functioning (examples, Audix UEM81C Battery Powered Condenser Mic, Audio-Technica AT8022) or if connected to your computer via USB, taking its power from your computer (examples, Audio-Technica AT2020USB USB Condenser Microphone, Shure PG42-USB USB Condenser Mic).

Note: I have not personally used any battery-powered or USB mics, so I cannot recommend any specific mic for you.  As with any piece of gear, you’ll need to do your own research as to what fits your needs best. Regardless of how it gets, it’s power; once you figure that out, you’ll be thrilled with the depth of sound you’re able to achieve.