The Home / Project Studio Microphone Cabinet
By Phil O'Keefe |
The Home / Project Studio Microphone Cabinet
Building a versatile and effective microphone collection doesn't have to cost a fortune
by Phil O'Keefe
I love microphones! For a recording enthusiast, they're the equivalent of a photographer's lenses - the devices that capture the raw sonic material that we sculpt into our finished aural masterpieces. Without microphones, your recording project will stall before it ever gets off the ground; unless you're working strictly with samples and virtual instruments, you simply have to have them - but how many do you need? And with so many models and types available, how do you decide which mics to get? We're going to answer some of those questions in this article.
First, let's look at some of the different types of microphones. There are three main types of microphones you're likely to encounter, each of which functions differently and has different general sonic characteristics: condenser microphones, moving-coil dynamic microphones and ribbon microphones.
Condenser microphones use a thin sheet of mylar with a thin layer of gold sputtered on it. This diaphragm is electrically charged, and vibrates when sound waves in the air hit it. The movement of the diaphragm relative to a charged backplate creates an electrical signal. This signal is way too low for your microphone preamp to handle, so an onboard preamp inside the mic brings that signal up to "mic level." Condenser microphones need either phantom power (usually 48V) to power the onboard electronics, or an external power "brick" to power them if the mic uses a tube circuit. Condensers are very good at capturing fast transients (the initial "start" of the sound), and have a generally bright and open sonic quality to them. They usually have the widest frequency response range. They are also expensive and somewhat sensitive to moisture and physical damage if hit or dropped. Condenser mics are available in both small and large diaphragm versions.
Moving-coil dynamic microphones are the type most familiar to the average musician. They use a thin sheet of mylar as the diaphragm, but with a coil of wire attached to it. A large magnet provides a magnetic field that the coil of wire sits in, and when the air hits the diaphragm and causes it to vibrate, an electrical charge is created through induction. Moving-coil dynamic mics tend to be fairly inexpensive, relatively rugged and immune to physical shock, wind and moisture, but at the expense of their high frequency and transient response - the relatively massive diaphragms take more sound pressure to overcome inertia. Like condenser microphones, moving coil dynamic microphones are available in both small and large diaphragm versions.
Ribbon microphones are another type of dynamic, but instead of using a coil of wire attached to a mylar diaphragm, they instead use a thin strip of corrugated aluminum suspended in a magnetic field. The ribbon's light weight means that these mics are generally very good with transients, and their sound is often described as detailed and natural. However, many ribbons have limited high frequency response, meaning you may need to add a bit of high frequency EQ to the sound. Also, most ribbons have very low output levels, and require a good mic preamp with plenty of gain (60-70 dB) on tap. Traditionally, they're also relatively fragile, and a decent blast of wind can destroy the ribbon element. Fortunately some newer models are more rugged, but you still need to be careful. Ribbon mics are often described as sounding warm and natural, and these characteristics have given them a resurgence of popularity in this age of digital recording.
Polar patterns determine how microphones pick up sound. Most readers will probably be familiar with cardioid directional microphones. These mics are much more sensitive to sound arriving from the "front" and reject sound coming from the rear. However, there are other polar patterns that can be useful for various applications. Besides cardioid, the two other polar patterns you're most likely to encounter are omnidirectional and bi-directional, also called "figure 8."
Omnidirectional microphones pick up sound that arrives from any direction. They are perfect for capturing the sound of the "room," and they usually have the most balanced sound and "flattest" frequency response. They tend to feed back easily, which is why they're rarely used live, and since they pick up everything, they're not good for isolating individual instruments when recording more than one at a time in the same room. They're perfect for picking up the sound of multiple or "group" vocals, and because they don't suffer from the proximity effect (an increase in bass as you get closer to the mic), they're excellent for use at near-contact distances from a sound source without sounding boomy.
Bi-directional or "figure 8" microphones like the Cascade Fathead II shown in Figure 2 pick up sound equally well from the front and rear, while offering near-perfect rejection of sounds coming from the sides. This polar pattern is the most susceptible to bass boost due to proximity effect. Most ribbon microphones have bi-directional polar patterns.
Having a selection of different polar patterns can be very useful. A good cardioid condenser coupled with a good bi-directional mic gives you the basic tools needed for Mid-Side stereo recording. A pair of bi-directional mics will allow you to record using the Blumlein stereo mic technique. They can also be excellent for recording a single person performing on acoustic guitar and vocals simultaneously by angling them in such a way that the front of the vocal mic is aimed at the vocalist's mouth, while the side is pointed towards the acoustic guitar, and so that the front of the guitar mic is aimed at the guitar, but the side (where rejection is near-perfect) is aimed towards the singer's head. Large diaphragm condensers with multiple, user-selectable polar patterns are great due to their similar adaptability. Some small diaphragm condensers are available with alternative screw-on capsules (Figure 3) with different polar patterns to expand their polar pattern options.
Large diaphragm condensers are often considered the "stars" of the mic locker, and they can be used on practically anything, although they're often used for the "featured" elements of a recording. Drum overheads and "room" mics, stereo applications (Blumlein, Mid-Side and spaced pairs), piano, acoustic guitars, lead and backing vocals, strings, brass, reeds and guitar amps are all commonly recorded with large diaphragm condensers. Be aware that sound arriving off-axis can sound "colored," and some large diaphragm condensers can sometimes be too "hyped" sounding in the high frequencies on some sound sources.
Small diaphragm condensers are also good for practically anything. They're commonly used as drum overheads, and for general stereo miking applications; especially for spaced and XY coincident pairs. Other uses include acoustic piano, acoustic guitars, hi hats, percussion "goody table" items and stereo ensemble recordings; especially choirs. They're generally more "realistic" sounding than large diaphragm condensers, with more natural off-axis response, although they do tend to have more self-noise than their larger cousins. Some models will overload when used up close on very loud sound sources. Pad switches that lower their sensitivity are useful in those cases.
Ribbon mics are slightly more specialized. Ribbons excel as guitar amp mics, and as drum overhead and "room" mics. They're also good on brass and sax, as "horn" mics on a Leslie (™) speaker cabinet, and even for instruments like banjo and fiddle. On vocals, the tonality can be smooth, detailed and "old-fashioned" or "retro" sounding. Watch out for wind blasts from instruments and singers, and their heavy proximity effect when used at close distances to the sound source.
Large diaphragm dynamic microphones are a good mic type to try whenever you're recording a low-frequency sound source; particularly when that source is very loud. Kick drums, floor toms, bass amps, Leslie (™) speaker drums, and low brass instruments like trombone and flugelhorn are good candidates for a
large diaphragm dynamic microphone. They are also very popular for broadcast vocal and narration recording, and can work great for hard rock vocals with the right singer. While they may be more expensive than other moving-coil dynamics, their versatility and low frequency capabilities makes it worth having at least one or two in your collection. Some models are designed specifically for kick, and may have a "scooped" lower midrange response, which may make them less versatile overall. Others such as the RE320 (Figure 4) offer switch-selectable responses for both kick and general purpose use.
Small diaphragm dynamics are the "workhorses" of the modern mic locker. They work well on snare, rack toms, congas, bongos, djembe and other smaller drums, and are the go-to mic for many engineers on guitar amps. If there's a chance of the microphone being banged around or otherwise subjected to a lot of abuse in the recording process, small diaphragm dynamics usually get called in for the job due to their ruggedness and low cost. Their frequency response generally does not reach as far into the highest and lowest ends of the frequency spectrum as most condensers do.
OUTFITTING THE MIC LOCKER AND BUILDING IT UP OVER TIME
As I mentioned in the caption for Figure 1 (above), a well-chosen "baker's dozen" assortment of microphones will cover 95% of the recording tasks a small project studio may encounter, giving you enough resources to track a typical small ensemble rhythm section of drums, bass and guitar simultaneously; but even with careful selection of versatile, budget-priced / high performance models, a dozen microphones can still cost a significant amount of money. If you can't afford to purchase everything at once, prioritize and get the basics, then add to it when you can. For example, as I pointed out in my Drum Miking article, you can start with a basic four-mic drum setup of a large diaphragm dynamic kick mic, small diaphragm dynamic for snare, and a pair of ribbon mics or small diaphragm condensers for the overheads. Even assuming you have enough mic preamps and input channels on your audio interface, you won't be able to mic other instruments such as bass, scratch vocals, or rhythm guitar simultaneously along with the drums, but each of those "drum microphones" has applications outside of drum kit miking. This means that when you're ready to do overdubs for rhythm and lead electric guitar, or to record the acoustic guitar parts, you can re-purpose the mics for those tasks. For example, if you're careful about picking a good multi-purpose large diaphragm dynamic microphone for the kick, it should be able to do double-duty on bass amp cabinets. The ribbon microphones or small diaphragm condensers that you used for drum overheads can work for acoustic guitar tracking.
When prioritizing, consider the types of recordings you do most often, and make your purchases with that in mind - then expand from there. If you mainly record fingerstyle acoustic guitar, getting a quality pair of small diaphragm condensers would probably be a wise place to start. If you mainly record voiceover artists, get the best quality, large-diaphragm condenser and large diaphragm dynamic mics that you can afford. Guitarists who work alone and rarely record drums should concentrate on a good ribbon mic, a good small diaphragm dynamic, and maybe also consider a large diaphragm condenser for amp room miking duties and a good pair of small diaphragm condensers for the occasional acoustic guitar overdub.
For a general purpose studio on a very tight budget, I'd recommend starting with the four-mic drum setup (with the small diaphragm condenser option for overheads) and a large diaphragm condenser; this will give you the basic tools you need to record practically any instrument singly, and you can add a pair of ribbon mics and additional dynamic microphones to the collection over time as your budget allows, to expand your ability to record multiple players simultaneously.
SOME SUGGESTED MODELS
Ask any ten engineers what their favorite microphones are, and you'll get ten different lists. Microphone preferences are a personal thing, and getting to know the various models and their sonic characteristics can be a life-long pursuit. Additionally, some of the best models can cost significant money - especially for top-of-the-line condenser and ribbon models, but there are some bargains to be had. Here are some suggestions for models that perform well and yet fall into the "affordable" price range (prices given are "street" prices). Some more expensive models are also listed to provide additional choices.
Large diaphragm condensers: AKG C214 ($399), Blue Bluebird ($299), MXL 4000 ($200), Neat King Bee ($349), Rode NT-1 ($269), Sterling Audio ST77 ($200). This is the one category where you may want to splurge a bit, and if the budget can be stretched, check out the Audio-Technica AT4050 ($700), Mojave Audio MA-201 ($700) and MA-200 ($1,100), AKG C414 XLS ($1,000), Neumann TLM102 ($700) and Shure KSM44A ($1,000).
Small and medium diaphragm condensers: Audio-Technica Pro 37 ($130), Audix Fusion F15 ($110 each, $200 / pair), MXL 603S ($100), Shure PG81 ($120), and Sterling Audio ST31 ($100). Moving up a bit in price and performance, the Audio-Technica AT4041 ($500 per pair) Blue Hummingbird ($299) and Neat Worker Bee ($199.99) are also good options.
Ribbons: Cascade Fathead II ($400 / pair), MXL R144 ($100). Higher-end mics include the Beyer M160 ($700) and Royer R-101 ($800).
Large diaphragm dynamics: Audio-Technica ATM250 ($180), E/V RE320 ($300), Heil PR40 ($325), Shure SM7b ($350).
Small diaphragm dynamics: Audio-Technica ATM-650 ($100), Audix i5 ($100), Granelli Audio Labs G5790 ($150), Heil PR22 UT ($115), Sennheiser E609 ($110), Shure SM57 ($100).
Small diaphragm dynamic "tom mics": Audix D2 ($130), Heil PR28 ($150), Sennheiser E604 ($140 each / $350 for a set of three).
THE ILLUSTRATED COLLECTION
The twelve microphones in Figure 1 are (top row) a pair of Audio-Technica AT4041 small diaphragm condensers ($500 / pair) flanking a Mojave Audio MA-300 ($1,300) multi-pattern large diaphragm tube condenser. Row two is a pair of Cascade Fathead II ribbon mikes ($400 for the pair with stock transformers), flanking a Neat Microphones Worker Bee ($199) medium diaphragm FET condenser, while row three shows a Shure SM57 ($100) and Audix i5 ($100) small diaphragm dynamics, Audio-Technica ATM250 ($180) and Electro-Voice RE320 ($300) large diaphragm dynamic mics and three Audix D2 ($130 each) small diaphragm dynamic / tom mikes. Total cost for all of these mikes new would be $3,169.00, which is not insignificant by any means, but each of these mikes would be a useful addition to any mic locker, no matter how extensive. In other words, this isn't "cheap" stuff that you will eventually outgrow and no longer find useful; with proper care, good microphones can last for a lifetime. With this collection, or something similar, you have the foundation of a microphone collection that can handle a wide variety of tasks and serve you well for decades to come. -HC-
Have questions about this article or what microphones to get for your mic cabinet? Want to tell us about your favorites? Then check out this thread in the Studio Trenches forum right here on Harmony Central!
Phil O'Keefe is a multi-instrumentalist, recording engineer / producer and the Senior Editor of Harmony Central. He has engineered, produced and performed on countless recording sessions in a diverse range of styles, with artists such as Alien Ant Farm, Jules Day, Voodoo Glow Skulls, John McGill, Michael Knott and Alexa's Wish. He is a former featured monthly columnist for EQ magazine, and his articles and product reviews have also appeared in Keyboard, Electronic Musician and Guitar Player magazines.