Building a Pro

A view of the mic closet at Nashville's County Q studio.

Compare notes with Nashville producer-engineer Mike Purcell, who runs down the essentials of a pro-level home-studio mic collection.

A well-rounded mic closet could take a lifetime to build. I’m constantly trying different things, but there's always a core set of mics I come back to because they’re reliable and provide good results. Many of these mics work on a wide range of instruments. By knowing my mics, I can make a choice that's going to enhance the sound of an instrument—especially guitar.

In this story, I’ve listed several options for each mic type covering a range of prices from low to high. A higher cost usually indicates that the quality of components and workmanship are better, leading to a more consistent product. Lower cost generally means quality control isn't as strict and that mics may differ more from their published specs.

You’ve probably heard this before, but the three main types of mics are dynamic (or moving coil), condenser (or capacitor), and ribbon mics. Let's work our way through each category.

Dynamic mics are composed of a voice coil suspended in a magnet. Incoming sound moves the voice coil within the magnetic field and a current is created. This is passed through a transformer to step up the voltage, and then sent to a mic preamp.

Dynamic mics are the mainstay of live sound because of their durability and ability to be used on loud sound sources without overloading. These are desirable characteristics in the studio when we’ve got to place mics close to a flailing drummer or mike up a Marshall Super Lead 100 full stack.

Even though dynamics all exhibit these same general characteristics, each mic will color the sound differently. Some dynamic mics work better on drums. They have an increased low-frequency response, a dip in the lower mids, and a bump in the presence range—essentially an EQ curve that sounds good on bass drums and toms. Others may have a more pronounced bump in the upper mids, making them a great choice for guitar amplifiers. While dynamic mics are typically used for the close miking of drums and guitar amplifiers, they are also well-suited to some vocalists.

A well-rounded mic closet in a home studio that cuts four- or five-piece bands would have at least 8 to 10 dynamics. Modern production dynamic mics top out around $600, and most are under $250.

Side note: Many manufacturers offer a drum-mic package—a great solution if you’re starting out. These usually include several dynamics for the close mics and a few condensers for the overheads and/or hi-hat. Plus, these mics can also be used for recording other instruments.

Condenser mics consist of a thin, charged diaphragm suspended over a metal plate. As sounds strikes the diaphragm, it moves and causes electrons to flow through the plate. This signal is amplified by internal electronics and passed through a transformer or field-effect transistor (FET) and is sent to a mic preamp.

Condenser mics are divided into two categories: small diaphragm condensers (SDC) and large diaphragm condensers (LDC). SDCs have a diaphragm of less than 1" and tend to be more responsive to transients and high frequencies. Their off-axis response is also more even.

LDCs have a 1" or greater diaphragm. They sound fuller, but off-axis mic response can be uneven. LDCs, because of their overall size, can be harder to position in tight miking situations.

Matched microphone sets require that the frequency response and sensitivity of the two microphones are very similar. This allows them to record a balanced stereo image. So, a well-rounded mic closet will have a matched set of SDCs and LDCs, and a few assorted condensers for other purposes.

With LDCs, manufacturers have families of mics that use the same basic components, but the higher-end mics will offer pattern selection or other features. Within the family, the sound will be similar. Examples are the AKG C214 and C414, and the Shure KSM32 and KSM44.

Ribbon mics function by suspending a very thin conductive metal strip between two magnets. Sound waves strike the metal strip, causing it to vibrate. The vibration in the magnetic field creates a current in the magnets. This is sent through a transformer, and then the signal is sent to a mic preamp.

A good mic closet should have several ribbon mics, and possibly more depending on the style of production. Ribbon mics have seen a resurgence over the past 20 years and there is a wide variety available, ranging from $200 to $1,500 and more. Ribbons are used on guitar amps, as drum overhead or room mics, and on horns, acoustic guitars, percussion, and vocals.

Tube mics are a subset of condenser mics. Up until the 1960s, condensers used a tube for the amplification of the low-level diaphragm signal. Tubes sound nice, but have a lot of issues: heat, high power requirements, and they can suffer from microphonics. In the ’60s, a solid-state replacement for the tube was created: the FET, or field effect transistor. The FET emulates tube characteristics and has two benefits: smaller size and reduced power requirements. The first solid-state condenser mic designs used the same circuit except for the FET substitution, but they sounded different, crisper. They had lost the tube character.

Tube mics are revered for their warmth, wide frequency response, and pleasing sound. They are most commonly used for vocals, but I’ve used them for every instrument. There's a robust market for inexpensive tube mic modification. Sometimes it's as easy as swapping a tube, while others do capsule and component level changes. These mods can greatly enhance the sound of an inexpensive tube mic. A good mic closet should have at least one curated tube mic. They start at about $499 and can range upwards of $30,000.

Some manufacturers with tube mics in the below-$1,000 price range include Avantone, Warm Audio, Golden Age, and Lauten Audio. My recommendation is to audition several and find the one that will have the broadest application for your recording situation. They won't sound exactly like their pricier counterparts, but they’ll give you a flavor in your mic closet that's only possible with a tube microphone.

Photo by Nick Sonsini

You’ve got to start somewhere when building your mic closet. If you’re not tracking full bands, I’d recommend starting with a couple dynamics (like the SM57) and a set of LDCs. With these mics, you’ll be able to cover basic overdub sessions. From there, borrow mics from friends, explore the world of ribbon and tube mic sounds, and discover what works best for your home studio.

Direct boxes, or DIs, are an integral part of any studio. They are used to connect (Hi-Z) instruments with low-impedance (Lo-Z) microphone preamps. Hi-Z devices, such as guitars and basses, have 1/4" outputs. The DI provides a 1/4" input to connect to your guitar and an XLR output which connects to a preamp. DIs also have a 1/4" output jack. This is used to pass the signal through the DI and connect to an amplifier. Often, a bass or guitar is recorded to two tracks—one signal from the DI and the other from an amplifier.

There are two types of DIs: passive and active. Passive devices have of an internal transformer that changes the impedance of the signal. Active DIs require a power source for their internal electronics and will have less signal degradation than a passive device. A good home studio should have at least one active DI and two passive DIs.

Modern DAW interfaces usually have built-in Hi-Z inputs via 1/4" jacks that allow you to connect directly to your interface. These negate the need for a DI.

Digital microphone modeling systems are a relatively new development. They combine a specially designed microphone with modeling software that allows you to record audio that sounds as if you had used a different microphone. The software models a variety of classic or vintage mics. The two frontrunners in this new tech are the Slate Digital VMS Virtual Microphone System and Universal Audio's Sphere L22 Microphone Modeling System (which was developed in conjunction with Townsend Labs).

They use a sonically transparent microphone designed to interface with their modeling software. The signal is passed from the mic through a neutral mic pre (one that doesn't color the sound too much) to your DAW input. The plugin is applied to the audio and an output mic model is selected. The result sounds as if it had been recorded with the selected mic.

Slate and UA accomplish this by testing and measuring a microphone's behavior and mapping that behavior out in software. The software knows the characteristics of the recording mic and processes the audio, applying the differences to the signal. The recorded signal now sounds as if it was recorded with a $20,000 Neumann U 67 (or whichever mic you’ve selected).

The benefit of these systems is that it is non-destructive. Just like amp modeling plugins, there is a dry sound recorded in your DAW, and the processing is applied with a plugin. You have the ability to modify it throughout the recording process, finding the sound that works with your final production.

These systems offer a huge range of sounds and offer mic selections that would not be available in your average home studio. And each system offers a selection of recognized mic models with an established track record.

• Slate Digital VMS Virtual Microphone System (mic and software $499 street): This system's ML-2 is a small diaphragm mic. Once recorded, sound is processed via the VMS plugin (compatible with AAX, VST2, VST3, and AU formats). The VMS software includes 13 mic models, ranging from the AKG C12 to the Shure SM7B. Two add-on mic bundles are available for purchase from Slate: Blackbird Mics ($199 street), featuring five mics from Nashville's Blackbird Studio, and Classic Tubes ($299 street), featuring five modeled mics.

• Universal Audio Sphere L22 Microphone Modeling System ($1,199 to $1,499 street): UA's Sphere L22 was developed in conjunction with Townsend Labs. The Sphere software works the same as VMS, tuned for the provided mic and offering 34 output mic models.

The Sphere system uses a dual-capsule mic. This allows the software to take the signal from both capsules and create a 3D sonic picture of the modeled microphone. In theory, this should offer off-axis behavior similar to the originals. The mic can use both capsules to create a stereo recording, too.

The software is available in UAD, AAX, VST2, VST3, and AU formats. It offers more tweakable parameters than the VMS. So, if you’re a knob twister and like to fine-tune your sounds, the Sphere is a good choice. The additional controls come with a higher price tag.