What is a dynamic microphone?
A dynamic microphone is a microphone that uses a magnetic field to generate an electrical signal. Vibrations in the air, such as from your voice, cause a tiny metal coil suspended within the microphone to move. When metal moves within a magnetic field, it creates an electrical current, and that current transmits the audio.
Audio engineers use dynamic mics for recording nearly any type of sound. Los Angeles-based producer, composer, and audio engineer Dave McKeever has used this type of microphone to record vocals, instruments, and ambient sounds. He shares some pros and cons of dynamic mics.
- Pros of a dynamic microphone: “Dynamic microphones are extremely durable,” Dave says. “They aren’t terribly sensitive to things like humidity, heat, and electric shock. A dynamic mic captures less detail than a condenser, which can be a good thing because that makes them more forgiving in noisy situations. They’re also simple to set up and require minimal work to optimize.”
- Cons of a dynamic microphone: “The flipside to dynamic microphones being less sensitive is that most models don’t capture the same level of detail as a condenser microphone or a ribbon microphone,” Dave says. “For live performance, this isn’t much of an issue. But for studio recordings, which often benefit from the rumble of lower frequencies or the breathy air of higher frequencies, you can lose something with many dynamic mics.”
What is a condenser microphone?
A condenser microphone is a type of microphone that creates audio signals using a capacitor — that’s a device made up of two metal-covered plates (the backplate and the diaphragm) suspended close together with a voltage passing between them. When vibrations from a voice or an instrument hit the diaphragm, it produces a change in voltage, and that voltage variation transmits audio signals. But in order for that signal to be heard, it needs to be amplified by a power source. That power source is usually in the form of phantom power, which comes directly through the XLR cable. Condenser microphones are popular among recording studio engineers for their remarkable ability to capture detail.
- Pros of a condenser microphone: Dave says there’s a lot of upside to condenser microphones. “Compared to a dynamic mic, a good condenser mic will have a wider frequency response,” he explains. “This means they’ll capture everything from very high frequencies to very low frequencies — pretty much everything the human ear can process.” You can expect a ton of detail in a condenser microphone recording, provided that the mic is properly set up and that you choose an appropriate model.
- Cons of a condenser microphone: “There’s no hiding any sound from a condenser mic,” Dave says. “It’ll pick up every sound in the room, whether you like that sound or not. They can also be harder to set up than dynamic microphones. For one thing, they require an external current of energy called phantom power. You can get phantom power from your audio interface, but it’s one extra thing to plan for. Finally, you may find that your condenser mic can’t handle the same sound pressure levels (SPL) as a dynamic mic before it starts distorting. For incredibly loud sounds, you’ll definitely want to use a dynamic mic.” Finally, Dave says condenser mics aren’t exactly “plug and play” the way that dynamic mics are. “No matter what,” he advises, “plan to spend a lot of time positioning condenser microphones and adjusting input levels in order to get the best sound".
Large vs. small-diaphragm mics: What’s the difference?
A microphone’s diaphragm is a thin membrane that is electrically conductive. It sits next to a metal plate within the microphone housing. Many contemporary condenser microphones use gold-sputtered mylar for their membranes. The sound of a large-diaphragm microphone will differ from that of a small-diaphragm mic.
Large-diaphragm mics, particularly large-diaphragm condensers, are some of the most detailed microphones on the market. They’re a standby for recording vocals, but you’ll also see large-diaphragm mics in front of guitar amps, acoustic instruments, and even drum kits. They can come in somewhat unwieldy shapes, and a large-diaphragm condenser requires external phantom power — which means you have to include a power source like a laptop computer, connected via a digital audio interface — but the sound of a good large-diaphragm mic is second-to-none.
True to their name, small-diaphragm microphones are smaller than large-diaphragm mics, and this makes them more portable. In most applications, recording engineers use small-diaphragm mics to record instruments. Because of their compact size, small-diaphragm mics can clip to a drum set and record individual pieces of the kit. They can also work for recording vocals, but for that, most engineers opt for large-diaphragm mics instead.
7 top choices for dynamic and condenser mics
Here are Dave’s top choices for dynamic microphones and condenser microphones.
Top dynamic microphones
- Shure SM58. This dynamic microphone is the true workhorse of a live performance stage. If you walk into a club and see a bunch of vocal microphones lining the stage, it’s a pretty good bet that they’re SM58s. As Dave says, “They’re incredibly durable — you could hammer a nail with one — and they have a really neutral sonic palette which means they can record anything without coloring the sound.” The SM58 is a great generalist mic that’s good for just about anything.
- Sennheiser MD46. Dave recommends the MD46 as a great dynamic microphone for interviews. “It has a longer handle than the SM58, which is good if you need to interview a subject but can’t stand too close to them.” Like the SM58, the MD46 offers a nice frequency response, a neutral sound, and a sturdy build.
- Shure SM7B. The SM7B is the go-to model for radio stations that have a lot of DJs cycling in and out. It’s a large-diaphragm dynamic microphone, and it’s forgiving for all types of voices. Dave notes that the SM7B “sounds as good as most condensers but it doesn’t require the same tweaking and adjusting you can expect when setting up a condenser.” While the SM7B doesn’t require phantom power, it does have high impedance that can only be overcome by a very strong preamp. Make sure your audio interface has one, or else invest in an external preamp. Note that the SM7B is a large mic, so it’s impractical for most field recordings.
- ElectroVoice RE-20. This is another mainstay of the recording industry and it’s the mic of choice for many broadcast announcers. It’s bigger and less sturdy than a Shure SM58 or a Sennheiser MK46, but its sound quality is considered superior. It is a little expensive for a dynamic microphone, but its sound is second-to-none.
Top condenser microphones
- Shure SM81. “This is a small-diaphragm cardioid condenser that is pretty rugged and portable,” says Dave, who sometimes brings an SM81 for field recording. The mic is long and thin and pretty easy to slide into tight spaces. It’s most commonly used to mic pianos, guitars, and drum kits — particularly cymbals.
- AKG C414. This is the priciest microphone on this list, but many audio engineers swear by it. “This large-diaphragm microphone is an incredibly flexible mic,” Dave says. “It has all of the five most common polar patterns, which you can access with the push of a button. It’s not cheap, but if you want a mic that sounds great for any application right out of the gate, the AKG C414 is a great, great choice.”
- Sennheiser MKE 600. This is a shotgun condenser microphone with a small diaphragm. Shotgun mics are very popular on film sets because they capture directional sound while remaining out of the camera frame. Dave frequently brings several to his film recording projects because they capture a great deal of detail without recording a bunch of unwanted background noises.
5 tips to make your microphones last longer
A microphone can be a significant investment. But if you care for it properly, a well-made microphone can remain functional for your entire recording career. These five tips from Dave will extend the life of your microphone.
- Put it away in its case. “If you’re going to spend hundreds of dollars on a microphone, get it a proper case so it doesn’t get beat up every time you transport it.”
- If you want to keep your mic set up at all times, get a cover. Dust can interfere with the internal components of your microphone, so keep yours covered when not in use.
- If you’re in a humid area, put some silica packets in your mic cases. “Moisture is never your friend for any microphone,” Dave says. Always keep some silica packets handy to absorb excess humidity.
- Avoid extreme temperatures, particularly heat. When left in extreme heat, like in a hot car, some microphones can suffer internal damage from melting wires. This tends to only be an issue with low-cost mics with budget wires and poor soldering jobs, but it’s not worth risking any mic in a hot car.
- Invest in a good mic stand. “Don’t drop your mics!” Dave says. At the very least, you’ll damage the microphone’s grille, which can hurt resale value. In other cases, you can dislodge a condenser capsule and render the mic useless. The best way to avoid dropping your microphone is to keep it on a sturdy stand. High-quality stands can be surprisingly expensive, but they pay for themselves thanks to the protection they provide.