***I originally wrote this article for D’Addario’s Orchestral Behind The Bridge blog. Please click here to view the original article.***
There are essentially three types of microphones: dynamic, condenser and ribbon. In my opinion, there isn’t necessarily a right or wrong type to use depending on the sound you’re trying to achieve, but there are some best use scenarios for which each microphone type is better suited.
Dynamic microphones are more ruggedly designed which is why they tend to be heavier in weight. Electricity is generated within the microphone when sound waves cause the thin metallic diaphragm and attached wire coil to move inside of the permanent magnet that surrounds the wire coil in its magnetic field (see Figure 1). Electricity from the power company is generated in a similar way (minus the sound waves). Since the dynamic mic has its own electricity source, I don’t have to turn on my audio interface’s phantom power switch which would allow voltage to be sent through a microphone cable to operate the microphone. Because the inner components of the dynamic mic are heavier in comparison to others, this microphone type has limited high frequency response which would be a disadvantage for higher pitched instruments. The cello’s fundamental and harmonic sound wave frequencies fall within the audio spectrum range of the dynamic microphone, so I wouldn’t have a problem using one if I’m playing on cello. The most common uses of dynamic mics are for guitars, snare drums, sound reinforcement, and voiceovers.
Condenser microphones are my personal preference for everything I do from recordings to small performances where I set up my own PA system. This type of microphone has the widest frequency range which makes it a good option for recording acoustic instruments, string sections, cymbals, and vocals. Condensers use two electrically charged plates instead of moving a wire coil through a magnet. This means that they can respond faster to sound waves than a dynamic mic, have better high frequency response, and can capture the quick attack of certain instruments such as drums. I do have to make sure that my phantom power switch on my audio interface is always turned on when recording or miking with a condenser mic or no input audio signal will register.
Ribbon microphones are the most fragile and have a relatively weaker output signal even though they can sound great when used properly. Instead of using a heavy wire coil like the dynamic mic, ribbon microphones use an extremely thin sliver of metal foil as a diaphragm. As a result of this design, you will get a fabulous high frequency response because the thin foil will move very quickly in response to acoustic sound. This thin foil design is also the reason why the output signal for any audio input level will be weaker than with the other types of microphones. In my opinion, this type of microphone shouldn’t be used in a manner where a sudden blast of air from an instrument or vocal could damage the thin and fragile foil ribbon. A ribbon mic may be a good option for an instrument that sounds brash when recorded using other microphones such as a piano or violin.
After deciding which microphone you want to buy or use, it’s always a good idea to learn how to properly place it for your recording or live show. Below are the ‘Five Secrets of Mic Placement’ from the renowned audio engineer Bobby Owsinski. I came across this list some time ago and refer back to it often:
- Stand in front of the instrument being played and listen. Listen for tonal balance and how the room responds to it.
- Use your hands and ears to simulate various microphone pickup patterns. See diagram below – the pickup pattern should be stamped somewhere on your microphone. When you find the spot that sounds the best, that’s where you want to place the mic as a starting point.
- For omni placement, cover one ear and listen with the other.
- For cardioid placement, cover one ear and cup your hand behind the other to listen.
- For “stereo” placement or a stereo pair, cup your hands behind both ears and listen. One common way to record in stereo is to place 2 cardioid microphones at a 90 degree angle pointing in the direction of your instrument. You can also use this listening technique for a built-in stereo pair of microphones on a device such as the Zoom H4n.Figure 3.
- You can’t place a mic by sight.
- Try changing mic position instead of changing EQ.
- Give a mic some distance. Distance creates depth. When recording, I will sometimes double mic my cello with one right at the bridge for clarity of sound and the other a feet away to capture the depth of the room. In my previous article, I mentioned that I had to set up an aggregate device to be able to record myself using my 2 different types of microphones. My mini condenser mic that has to be connected to the audio interface is the one that I position right by the bridge of my cello because it doesn’t pick up sound very well at far distances. My USB Apogee MiC is the one that I place approximately 1-2 feet directly in front of me so that I can capture the sound waves after they’ve had a chance to blossom a little bit.
Please note that neither myself nor D’Addario is a definitive authority on this topic. This is meant to be an informational article for those who are novices in this area.