If you are serious about your voice over career, it is important to have a working knowledge of the tools available for voice over actors. For instance, the choice of microphone is crucial for quality audio recording.
However, before you jump into buying a microphone, it helps to do research on how microphones work, the reasons for acoustical treatment, and pretty much anything else that has to do with recording the human voice. You need to remember that the primary purpose of any high-quality recording is to re-create the reality of the moment in the most authentic and believable way possible. The simple fact is that the better the mic, the more authentic and accurate the audio recording will be. In fact, if quality was not a concern, we’d all still be using crystal or carbon microphones!
The Difference Between Dynamic and Condenser Microphones
Here’s the difference between dynamic and condenser microphones – and it has absolutely nothing to do with “a specially treated room.” To discuss this in detail would take a lot of space, so we’ll cover only the basics.
- Dynamic microphones use a moving coil design – sort of like a loudspeaker in reverse. The mic’s diaphragm is attached to a coil of copper wire that surrounds a permanent magnet. Sound waves striking the diaphragm move the diaphragm, creating a change in the magnetic field, which in turn creates a current flow in the mic cable that is proportional to the movement of the diaphragm. Analog sound waves are converted to electrical energy. Although some dynamic mics are very, very good, the mere facts that the diaphragm must physically move and that there is resistance due to the permanent magnetic field mean that most dynamic microphones have a limitation when it comes to reproducing high frequencies. The comparatively slower response time of the dynamic mic also has the effect of masking or minimizing some sounds that will be picked up by a condenser mic.
- Condenser microphones use an electrically charged stationary plate and a moving plate to replace the moving coil diaphragm of the dynamic mic. The use of two plates to store a charge is the design of a capacitor (which is also known as a condenser). Thus, the name condenser microphone. The two plates in a condenser mic are very thin and very close together. Instead of a permanent magnet, a condenser mic requires a phantom (or external) power supply to provide an initial voltage across the two plates. When sound waves strike the movable plate, the voltage changes, thus converting analog sound waves to electrical energy. Because there is no resistance from a magnetic field, a condenser mic can respond extremely fast. This is why condenser mics seem to pick up everything. They actually do, because the condenser mic can “hear” a lot more than a dynamic mic. The faster response allows a condenser mic to reproduce a much more realistic and uncolored sound, especially in the higher frequencies.
So, why are high frequencies important? Because the nuance and subtlety of communication lives in the harmonics of speech and music. And the harmonics are in the higher frequencies. The average human voice is in the frequency range of around 80 Hz to just over 3,500 Hz. But the human ear can hear a frequency range of roughly 20 Hz to 20,000 Hz. All the details of communication reside in those frequencies above 3,500 Hz.
There are many designs for both dynamic and condenser microphones – and both types have their advantages and disadvantages. However, when it comes to recording the human voice, the more accurate the recording can be – the better.
Noise reduction falls in the category of audio signal processing. ALL audio processing is designed and intended to either create an effect or attempt to correct for aÂ deficiencyÂ in an audio recording. Thinking that noise reduction will change a poor recording to one that is professionally acceptable is simply the result of a serious lack of education.
Most producers today want recordings that are pristine and clean, of the highest possible quality, and without any audio processing (or very minimal processing). This is why condenser microphones are the preferred mic for voiceover and why it is so important for voice actors, singers, and other performers to have at least a basic understanding of the recording process, how their equipment works, and the importance of recording in as acoustically perfect an environment as possible.
James R. Alburger