Choosing the Right Mics for your Studio
Left: A great dynamic mic is essential for capturing great guitar tones and the Shure SM57 is the go-to dynamic for many recording engineers.
Middle: A ribbon mic like the R-121 from Royer Labs provides a warm, rich tone that can stand alone or be combined with either a dynamic or condenser mic for a “composite” tone.
Right: Using a condenser mic like the Rode NT1-A is a good option when you want sonic detail and wide frequency response.
Here we are with the sixth installment of our ongoing discussion on how to best equip your studio. We’ve now reached the point where we need to talk about capturing your guitar signals. And that means microphones! With hundreds and hundreds of different mics on the market—at all levels of the price-point spectrum—narrowing down your choices and picking the best ones for your studio can be a serious challenge. So first, let’s break down the huge pool of mic options to three broad categories, based on how they work.
Dynamic Mics. Dynamic microphones work kind of like a speaker in reverse. Sound waves strike a diaphragm inside the mic and cause it to move back and forth. The diaphragm then moves a coil of wire that’s wrapped around a magnet, which generates an electrical current. Simple, durable, and effective for potentially loud sources like electric guitar cabinets, dynamic mics also tend to be quite affordable. Providing a thick and punchy sound, dynamics are often the first choice of many engineers for capturing the electric guitar, both in the studio and onstage.
Condenser Mics. A condenser microphone has a thin diaphragm that moves back and forth in response to sound waves. Located next to a charged plate, the moving diaphragm and plate create a changing capacitance (condenser is another word for capacitor) that represents the sound waves as voltage. Condenser microphones generally offer wide frequency response, meaning they cover the full spectrum by capturing low and high frequencies. They’re sensitive mics, so they aren’t as rugged as dynamics, but the trade-off is that they can be more responsive. Condenser mics often have switchable polar-patterns, which allow you to change how the mic responds to sounds that are off axis (not coming into the front of the mic). This makes them more versatile since you can control how much outside sound will bleed or leak into the mic while you are recording.
Because of the way they operate, condenser microphones require a power source. Depending on the mic, the power source can be internal batteries, external power from a dedicated supply, or supplied from your mixer or preamp in the form of phantom power—which is carried over the microphone cable.
The condenser category can be further subdivided into small-diaphragm and large-diaphragm microphones. Smalldiaphragm condensers tend to work well on acoustic instruments (such as steelstring and nylon-string guitars), while large-diaphragm condenser mics are a popular choice for vocals, piano, electric guitar, and more.
Ribbon Mics. Ribbon mics are conceptually similar to dynamic mics. They use a stretched, corrugated strip of metal (the ribbon) that’s suspended in a magnetic field. Sound waves move the ribbon, and this creates a voltage that flows out of the microphone. Ribbon mics were some of the earliest microphones on the scene and they have the advantage of responding with a sound that’s very pleasant to the human ear. They provide warm top end without harshness, full lows, and rich midrange. However, they generally don’t have the detail of a condenser mic or possess the ruggedness of a dynamic.
So which type of mic is best for recording the electric guitar? All of them! Each may offer a tonal option that’s ideal for a given guitar sound. The only real way to know is to try each and determine which one sounds best for the particular sound you are recording. If that’s not an option, then you need to look at a few other factors. One key factor to consider is the other potential sound sources you may record with the microphone. If you can only have one mic and it needs to cover a lot of bases (electric guitar, acoustic guitar, vocals, percussion, etc.), then I would recommend a large-diaphragm condenser mic. But if your one mic will only be used to record guitar cabs, then a dynamic microphone will serve admirably. Countless records, including many of the classic recordings we all know and love, have been made with only a Shure SM57 for the electric guitar. Would I want a ribbon mic as my only microphone? In specific situations, yes. If I know that my guitar tone works well with a ribbon and I’ll only be recording that particular tone, sure, a ribbon would be a fine choice.
The best possible scenario is to have a choice of mics, which is why commercial studios have a huge selection available for their clients. Having multiple mics on hand provides two important benefits. First, you can choose the mic that sounds best on a particular cabinet or guitar by matching the tone and response of the mic to the sound you are capturing. Second, you can create what I call “composite” guitar sounds by simultaneously placing two or more types of microphones on the same amp. For example, you might place a condenser for detail and wide-ranging response, a ribbon for a warm and rich sound, and a dynamic for a punchy, thick tone. When it’s time to mix your tracks, you can then combine and balance the individual sounds from each mic to create the overall sound you want.
Be sure to check back next month, when we’ll continue our discussion of microphones and the rest of the “capture” part of your studio rig!
Mitch Gallagher is the former editor in chief of EQ magazine. He’s written more than 1000 articles and six books on recording and music technology, and has released an instructional DVD on mastering. His upcoming book is entitled Guitar Tone: Pursuing the Ultimate Electric Guitar Sound. To learn more, visit mitchgallagher.com.