Looking for microphone and gear recommendations to help you become a better podcaster? Boy have you come to the wrong place! It’s the number one question people ask about podcasting and the first place folks go wrong. The secret to good podcasting is good content and taste, not in the flimsy hope that some microphone with gold flecking is going to make you sound like a superhero. Take the time to get to know your gear and learn the strengths and weaknesses. So what qualities should podcasters and producers be looking for in a microphone?
Microphone Basics: What is a Transducer?
Microphones are a form of transducer. They convert energy from one form (acoustic or kinetic energy) to another (electrical energy). There are three transducer types that are commonly associated with microphones: dynamic, condenser and ribbon transducers. However, for most vocal applications, dynamic and condenser microphones are used. Ribbon microphones, while excellent in quality for sound reproduction, tend to be very expensive, and extremely delicate.
Dynamic v Condenser
Dynamic microphones operate by suspending a coil of wire connected to a diaphragm inside a magnetic field. When sound vibrates the diaphragm, the coil vibrates and produces an electrical signal.
- Handle heat and humidity well.
- High volumes without distortion
- Rougher, but usable audio signal.
Dynamic microphones are good for general vocals that don’t necessarily need accurate and smooth reproduction, such as interviews, hosting and live venues.
Due to the rougher sound characteristics, dynamic microphones with a cardioid pattern tend to eliminate more background noise, but may lose some nuances in a performance. This makes them well-suited to podcast hosting, general voice recording and recording voices outdoors for voiceover or interviews, as well as for recording very loud items, like drums, guns and explosions.
Condenser microphones operate by vibrating a conductive diaphragm against a charged backplate to convert acoustic energy to electrical energy.
- Smooth frequency response
- Clear, detailed sound with crisper highs
- Excellent low-frequency response
- Not suited to extremely hot or humid environments
Condenser microphones are good for most studio applications, including voice acting. They produce a clarity of voice while giving the voice both warmth and presence.
Condenser microphones are industry standard for voice actors. The Neumman (pronounced NOY-man for you lubbers) U47 is iconic and has defined the sound the voiceover industry and producers are looking for. If you have around $4000 to spend on one microphone, I highly recommend a U47. For the rest of us, there are comparable mics that offer exceptional quality.
Condenser microphones are also exception for field recording, as they are more sensitive than dynamic microphones with a flatter response suited for capturing detailed audio.
Polar patterns illustrate how a microphone reacts to sounds coming from different directions. There are several polar pattern types, but our main focus for vocal microphones is on omni and cardioid polar patterns.
An omnidirectional microphone receives sound with equal sensitivity on all directions. This means that audio coming from the rear and to the sides of the microphone will be picked up with equal volume and clarity.
- Pick up of room reverberation
- Extended low-frequency response
- Lower cost
Omni microphones are good for recording situations where sound isolation is not needed or wanted. They are particularly useful for interviews and situations where more than one vocal needs to be recorded and sound isolation is not a factor.
Cardioid microphones are most sensitive at the front of the microphone, typically about 6dB less sensitive to the sides and around 20dB less sensitive to the rear of the microphone.
- Less reverb pickup than omni
- Less room noise pickup than omni
- Minimizes off-axis pickup
Cardioid microphones are ideal vocal microphones for one-voice-one-microphone applications. Voice actors and show hosts benefit from off-axis pickup reduction focusing the sound on what matters most: the speaker’s voice. A majority of studio-based professional audio requires unidirectional microphones (cardioid, hypercardioid, supercardioid). Voice actors and podcast hosts (and vocalists!) will likely find that microphones with a cardioid polar pattern will best suit their needs. Hypercardioid and supercardioid mics work well, too, depending on your voice and application, however they tend to be more expensive and lacking in the warmth that a large diaphragm cardioid delivers to more resonant male and female voices.
Frequency response refers to the range of frequencies your microphone can accurately reproduce at equal level. Understanding frequency response is one of your best tools when researching audio gear.
Simply put, frequency response show how a microphone affects the way your voice sounds. In general, when looking at a frequency response graph, you want the graph to be as flat at possible in the frequencies the microphone is being used to produce. In terms of voice, we are most concerned with the frequencies between 80Hz and 12kHz, the human vocal range.
Some microphones will have slight peaks in the 5-12khz range to improve presence, or some lift in the 500-800 hz range to improve warmth. These characteristics can be desirable depending on your production and scope.
In order to reduce low-frequency rumble and high-frequency hiss, microphones that roll off below 80Hz (high pass) and above 12kHz (low pass) are best suited for voice. This is especially helpful in cutting down on noise from vehicles and HVAC systems. However, this can also be accomplished by using an EQ highpass and lowpass to filter out these frequencies.
Here are some other factors to consider when researching and purchasing a microphone.
Impedance is a measure of a microphones resistance. Higher resistance in a microphone introduces hum and reduces high frequencies, making the recording sound noisy, or thin. Low-impedance or low-Z microphones allow long mic cable runs without introducing noise or reducing frequencies.
Sound Pressure Levels (SPL)
Sound pressure levels indicate the maximum sound intensity a microphone can handle before distorting. In general, a spec of 120dB or greater is desired. For podcasters miking loud instruments such as brass or drums, microphones with a higher maximum SPL will be desired.
Equivalent Noise Level
Also known as self-noise, the equivalent noise level is the electrical noise or hiss a microphone produces. In general, a self-noise specification of 28dB and lower is acceptable for quality recording.
Signal to Noise Ratio (S/N)
The difference (in dB) between a microphone’s sensitivity and the equivalent noise level. 64dB and higher is good.
There’s a lot of subjectivity in determining the best microphone for an individual’s use. The biggest determining factor tends to be price range. At minimum, the best microphone for the job is the microphone that best captures (or enhances) the frequencies of the sound source as accurately as possible with the lowest amount of noise within your price range. Here’s what to look out for depending on your recording purposes:
- Large-diaphragm dynamic or condenser
- Cardioid polar pattern
A large diaphragm microphone allows room for warmth to deliver that “broadcast host” sound. Using a dynamic or condenser is largely a matter of taste. However, if you are in a particularly noisy environment, a dynamic microphone is typically less sensitive and will pick up less noise.
- Large-diaphragm condenser
- Cardioid polar pattern
For the voice actor, a condenser mic is industry standard for their high sensitivity to capture nuances in the voice and clarity in the articulator frequencies (That is, frequencies associated with sounds made by the lips, the teeth, the tip of the tongue and the soft palate, including most consonant sounds). Condenser microphones deliver a warm, smooth sound that captures the presence of the actor.