Microphones
How did the legendary engineers of the past use them?
Introduction
At The Recording Session Vault, it is an important component of our mission to promote an understanding through education about how the great music of the past was created. While part of my mission is to write biographies of the people behind the music, feature articles about the great studios, and also to examine the technologies and to spotlight the companies that created them that have been so crucial to the development of popular music, it is also important to understand how the process of creating music actually worked, as well. With this educational series, we will explore the following topics: how the process of recording worked and how and why the technologies that were so important to that process were utilized. Plus, we will also discuss the products that engineers used to record the great popular music that we have come to love and to cherish.
There is absolutely no doubt that the most important component in any signal chain is the microphone which is being used to record a source. Each of the legendary recording studios that I was fortunate enough to have the opportunity to work in had excellent microphone lockers with models that could be used to record anything from a country music song to a classical symphony (and everything in-between). Every legendary engineer that I had the opportunity to work with were masters at using microphones— knowing which models to use and the techniques to use them. In this article, I am not going to spend a great deal of my time in this article on microphone techniques, rather I am going to simply introduce you to the microphones that we would have used for recording the following sources: vocals, drums, acoustic guitars, electric guitars, and the piano.
There are three different types of microphones— dynamic microphones, condenser microphones (including those which use a tube-based power supply) and ribbon microphones. What a microphone is capable of reproducing can be mapped or described as their polar pattern. There are also three differing polar patterns: cardiod (a heart-shape that is close to the front section of the microphone, or diaphragm); bi-directional (or figure of eight, which is a pattern of reproduction which covers both sides of the microphone— so you can record two speakers at once, for example) and omni (the microphone can pick up an entire room). The differing types of microphones, which differ based on their elements, also have differing capabilities for what they can reproduce— dynamic microphones always feature a cardiod pattern, ribbon microphones are almost always bi-directional (a few newer models now feature cardiod patterns) and condenser microphones with their powerful elements and amazing clarity can feature cardiod, bi-directional or omni directional polar patterns. The size of the diaphragm is also important because it tells you a lot about what the microphone can be used to record
At its essence, a microphone is a very simple device. It is really a speaker in the reverse. It is a transducer. It uses an electromagnetic element to change sounds into electrical pulses, which are boosted by a preamp and then changed in the reverse by another transducer— a speaker— into the sounds that you are able to actually listen to. (I think that sometimes we make what is actually happening in the world of professional music recording much more complex than it actually is.) The microphone was actually invented at roughly the same time as the telephone in the late 1870s. It is not a new technology by any means. The first microphones were simply dynamic microphones. By the 1920s, both condenser and ribbon microphones had been introduced for the purpose of public address announcements and radio broadcasting.
During the 1930s, as music for film and radio became important components of popular entertainment, ribbon microphones became very popular in America. In Europe, important innovations in condenser microphones made them popular for recording music and in the realm of radio broadcasting, especially in the years following the Second World War. During the 1950s, ribbon and dynamic microphones remained highly popular in American recording studio facilities. But, by the early 1960s, ribbons began to be replaced as microphones for recording vocals and large-scale orchestrations by tube-based condenser microphones, largely made in the nations of both Northern and Central Europe. In the late 1960s, tube-based designs began to fall out of favor in recording studio equipment, and a number of condenser microphones— requiring phantom power from the console preamps were introduced, many of which remain the workhorse microphones of today along with their dynamic counterparts for the purpose of recording music.
From the 1970s to the early 2000s, most of the music that you would have heard on the radio would have been recorded using a combination of condenser, tube-based condenser and dynamic microphones. Within recent years, perhaps since the growth in the use of digital audio workstation software programs and their corresponding hardware interface components, ribbon microphones have seen a resurgence in the world of professional music recording in their use as companies such as AEA and Royer Labs have developed models which can withstand higher sound pressure levels (louder sound sources) without distortion or even damage occurring.
What are the three different types of microphones and how would the legendary engineers of the past have used them?
Dynamic Microphones
The dynamic microphone is a simple device. Using an electromagnetic moving coil element, it is a transducer or speaker in the reverse, as noted above. The vibration of the electromagnetic element is what leads to the process of taking sound waves and transferring them intro electrical pulses. Dynamic microphones tend to be very hardy and take a tremendous amount of sound pressure level quite well. Therefore, they tend to be used on loud sound sources such as screaming vocalists, drums and electric or bass guitar cabinets. Dynamic microphones always feature a cardiod polar pattern.
Ribbon Microphones
A ribbon microphone actually works quite similarly to a dynamic microphone, in that it also has the use of electromagnetics, but instead of a moving coil, it features a small corrugated ribbon (believe it, or not— usually made of aluminum foil). With a thinner element, ribbon microphones can capture sources with more clarity and detail than a dynamic microphone, but it also means that they are more likely to be damaged by high sound pressure levels. In recent years, such companies as AEA and Royer Labs have developed hardier ribbon technologies with microphones that not only capture sources in stunning detail but are also able to withstand higher sound pressure levels. Ribbons are used quite often to record both acoustic and brass instruments, plus, can be used for vocal recordings, as well. Ribbon microphones almost always feature a bi-directional polar pattern (newer models now feature cardiod polar patterns, as well).
Condenser Microphones
Condenser microphones use thin metal plates, which act as capacitors that are sensitive to sound pressure level changes, to change soundwaves into electrical pulses. In order to operate, condenser microphones require a power source— either 48-volt phantom power or a vacuum tube-based power supply. Condenser microphones have much more sensitive elements than either dynamic or ribbon microphones and therefore can reproduce sources with much more clarity. The elements in these microphones can also take very high sound pressure levels, as well. Therefore, condenser microphones can be an excellent choice for almost any type of sound source, but are not as hardy as dynamic microphones on extremely loud sound sources. Tube microphones, with their warm circuitry are an excellent choice for rooms, vocals, stringed instruments and pianos. These microphones also tend to be much more expensive, too. Condenser microphones can feature either cardiod, bi-directional or omni polar pickup patterns.
How did the legendary engineers of the past use the amazing microphones that could be found in the mic lockers of great recording studio facilities?
In this section, I am going to describe how the legendary recording studio engineers of the past used the amazing microphones that could be found in the mic lockers of famed recording studio facilities to record the following sources: bass, drums, electric guitar, acoustic guitar, piano and a vocalist. If a microphone model is not currently made by a certain manufacturer, but there is an updated version of it, I will place the updated version of it in parenthesis for you. If I used a microphone on my own while recording a session, it will have an asterisk. Though I will tell you where the microphones were placed, keep in mind that just moving a microphone a fraction of an inch can make a tremendous difference in a recording.
Bass
Interestingly enough, I never saw a single engineer put a microphone on a bass guitar amp for a tracking (recording) session, as an assistant engineer in Nashville, Austin or Los Angeles. In every single tracking session, I saw engineers simply have the bass guitarist plug their instrument into a direct box. A direct box is a simple device which boosts a line level signal so that it can be monitored or recorded in a clean fashion. As an assistant engineer who spent most of his time setting-up for tracking (or recording sessions), it was always very easy and simple to set-up to record the bass guitar. However, I did see mixing engineers re-amp the bass and they would place the following microphones about 3-4 inches away from the main speaker in the cabinet and point it in the sweet spot at the midpoint in-between the center of the speaker cone and its edge. In my own sessions, I would just keep it simple and use a DI Box.
On a bass guitar amp, I have seen the following microphones used— Neumann U47, Neumann U47 FET and Electro Voice RE-20. The direct box that was normally used was a Countryman Type 85 DI Box.
Drums
Setting-up the microphones on a drum kit could take the majority of your time in preparing the studio for a session. The time that it takes to set-up a drum kit for a recording session depended upon two factors— how many microphones an engineer would want to use on a drum kit and how many drums there were in the kit. I did work with engineers who would put a microphone on both the top and the bottom of the snare and each of the toms, which could mean up to ten microphones (or more) on just those drums in the kit. The top microphone for each of these drums was placed pointing at a spot about two to three inches inside the head of the drum, where the tone of the drum could be accurately captured without the worry of having the drummer accidentally strike it. The kick drum would normally have just a single microphone that was placed inside the hole in the resonant head (outer head, away from the beater) and pointed at a sweet spot in-between where the beater would strike and the outer part of the shell. There are engineers (especially now who use a microphone outside of the kick drum), but in my experience there was only one engineer who pointed a microphone outside of the kick drum at the sweet spot on the resonant head after making a tent using blankets to isolate the power of the sound of this particular drum. Each of the microphones, with the exception of the microphone on the outside of the kick drum, were always dynamic microphones. (NOTE— While each of the descriptions discuss what I would set-up as an assistant engineer, when I engineered sessions on my own, I only used a single microphone on each of the drums. I also miked the hi-hat, the overheads and the room, but not the individual cymbals. I always enjoyed the results of this minimalist approach that I would do on my own for songwriting demo tracking sessions. The mics that I would use on my own sessions are also listed below and marked with an asterisk.) A single small diaphragm condenser microphone was always placed at the midpoint from the edge to the center of the hi-hat cymbals. This same technique was also used (if the engineer chose to mic each of the cymbals) on both the crash and ride cymbals with two small diaphragm condenser microphones. Every engineer that I worked with would take their time in having us set-up a pair of overhead drum microphones which were always large diaphragm condenser, or even tube condenser microphones. These microphones were placed about three to four feet above the kit to capture a perfect stereo image of the kit. A pair of microphones were always placed as room mics usually 8-10 ft. in the air on boom stands to get both a stereo image of the drum kit and the sounds of the reflections in the room in which the kit was being played. The room mics were always large diaphragm tube condenser microphones. Below is a list of the microphones that I would set-up for legendary engineers for the purpose of recording a drum kit.
On the drum kit, I have worked with legendary recording studio engineers who have used the following microphone models:
Kick Drum (inside)— AKG-D112, Audio-Technica ATM25 (now ATM 250), Shure Beta 52, * Electro Voice RE-20 or a Sennheiser 421
Kick Drum (outside)— Neumann U47 FET
Snare Drum (top)— * Shure SM57
Snare Drum (bottom)— Shure SM57
Toms (top)— * Sennheiser 421s or 504s (now 604s)
Toms (bottom)— Sennheiser 421s or 504s (now 604s)
Hi Hat— * Neumann KM84 (now KM-184) and AKG-451
Cymbals— Neumann KM84 (now KM-184) and AKG-451
Overheads— AKG C414s, Neumann U67s, Neumann U87s, AKG C-12s and * Audio-Technica 4050s
Rooms— Neumann M49s, * Neumann M149s and AKG C-12s
Electric Guitar
How the legendary engineers of the past that would have miked an electric guitar amp was not a real mystery, but as with any instrument, it required listening to find the sweet spot. Most of the time, the microphone (and it was just one microphone per speaker in a cabinet— I never saw an engineer put more than one microphone on an amp) was placed at a point midway between the speaker cone and its edge. Also, I only saw two differing microphone models used on an electric guitar or a steel guitar amp (working in traditional and pop country music, we worked with fabulous steel guitar players) the vast majority of the time. These two microphones were the Shure SM57 and the Sennheiser 421.
On an electric guitar amp, I saw legendary recording studio engineers use the following microphone models: Shure SM57, * Sennheiser 421 and the Neumann U87.
Acoustic Guitar
While working in Nashville recording studios during the great period of popularity for country music in the 1990s and early 2000s, I had the opportunity to watch a number of legendary engineers record fabulous acoustic guitar players. Depending upon the guitar itself, every engineer would mic an acoustic guitar on the sweet spot somewhere between the 8th and the 12th fret on the instrument about 6-8 inches away from it. Never did I see an engineer place a microphone in any other location. Only on one occasion did I see an engineer use a different type of microphone other than a large diaphragm condenser or tube condenser microphone and this microphone was a small (or pencil) condenser microphone.
On an acoustic guitar, I saw legendary recording studio engineers use the following microphone models: AKG C-12, Neumann U47, Neumann U67, Neumann U87, * Audio-Technica 4033a, Sanken CU-41 and the Neumann KM-84 (now KM-184).
Piano
The piano may be the most beautiful instrument that you can find in any legendary recording studio facility anywhere in the world. I have worked with legendary recording studio engineers who have placed microphones on some truly remarkable grand pianos. Those engineers always placed just two microphones on a grand piano— one which was centered and used to reproduce the high strings on the instrument and one which was centered and used to reproduce the low strings on the instrument. The two microphones which were placed on the grand piano were always large diaphragm condenser microphones.
On a grand piano, I saw legendary engineers use a pair of the following microphone models: Neumann U67, AKG C12VR, AKG C12, Neumann U87 and Sanken CU-41.
Vocals
The most important performer in the process of music recording is the lead vocalist. In order to select a microphone for a lead vocalist, our producer (my boss) would always have what is referred to as a microphone shootout. A collection of classic microphones— each of them were large diaphragm or tube condenser microphones, would be set-up for the vocalist who would sing a verse of a song on each one of them and then the producer, artist and lead engineer would offer their input and a microphone for the performer would be selected. This microphone would be used to record their performance on every song throughout the creation of their album project. For background vocalists, we always used the same microphone. Due to the differences in male and female vocalists, I will separate the two when listing the microphones that we used to record them below— however, I will not reveal who the artists where in the listing.
On vocalists, I saw our producer, engineering team and the artists choose to use the following microphone models:
Female Vocalists: * Neumann M49, Sanken CU-41 and Neumann U67
Male Vocalists: AKG C12, * Neumann U67, Manley Reference Gold, Neumann U87, Neumann U47 and the Telefunken ELA M251
Background Vocalists: Neumann U67
Why were the microphones that we keep seeing on this list so important to the legendary engineers of the past in the process of recording music?
As you read through this list, there are a few microphone models which keep coming up time and time again. The Neumann U67 and U87 and the Shure SM57 and Sennheiser 421 are all microphone models that you probably keep reading about repeatedly. Each of these microphones are very special in their own right.
Both the Shure SM57 and the Sennheiser 421 are classic dynamic microphones. The Shure SM57 is a dynamic microphone that is famed for its toughness. I treated an SM57 with the same respect and reverence that I would give to any microphone. It can take an enormous amount of sound pressure level and sounds great on drums, electric guitar amps and actually would make a great public address announcement microphone. It has a very tight cardiod polar pattern and so therefore it can be used on a source and it will not pick up any of the other instruments around it. This microphone has probably been heard on more snare drums and electric guitars throughout the history of popular music than any other with the exception of the Sennheiser 421, which it is often used alongside to record a drum kit. Much like the SM57, the Sennheiser 421 is a dynamic microphone which can take tremendous sound pressure levels and also has a very tight polar pattern. Also, like its counterpart, the 421 has been used on probably more hit songs to record toms in drum kits than any other microphone and has been a staple in recording electric guitar amps, as well. The 421 is also an excellent microphone for a kick drum. Both the SM57 and the 421 are also great for voice applications, as was mentioned earlier. I think it is important to mention that these two microphones are not just incredibly durable and easy to use, but that both of them are also incredibly consistent in delivering great results. Neither of these two microphones are very expensive, in fact, both of them are among the most inexpensive and also rank among the oldest microphone models that you can find in the mic locker of any recording studio facility.
However, the U67 and the U87 are both legendary microphone models from Neumann that are very different from the two classic models which have just been discussed. The Neumann U67 may be the greatest microphone ever created for the purpose of recording music. On the other hand, the Neumann U87 may be the most versatile and recognizable microphone to ever be created for the purpose of recording music. The two microphones are similar to a point, in fact, the U87 was created as a successor to the U67. While the U67 is creamy and smooth on just about every single source you place in front of it, the U87 is sharper and more detailed. If you were to build a mic locker around a single microphone, it would be hard to argue against either the U67 or the U87, both of which have been used on countless hit songs since their introductions in 1960 and 1967 respectively. The U67 is a tube-based large diaphragm condenser microphone which sounds great on vocals, drum overheads, acoustic instruments, pianos and can be used as a room mic for recording choirs and orchestras. The U87 is a bit more durable and also sounds great on vocals, electric guitar amps, acoustic instruments, percussion, brass instruments, drum overheads, pianos and as a room microphone for a variety of applications. Both microphones offer cardiod, bi-directional (figure of eight) and omni polar pickup patterns. These microphones are incredibly durable and are also a true long-term investment. The U87 has been available since its introduction in 1967, though it went through a brief series of changes in the 1980s which culminated in the release of the current version, the U87ai in 1986. In 2018, the U67 was re-released for the first time since the original production of this remarkable microphone was brought to a conclusion in 1971. Now both of these amazing microphones could become the staples of your mic locker, along with other classic mics such as the Shure SM57 and the Sennheiser 421.
Which of the classic microphones of the past that are listed in this article that would be great selections for an educational institution are still being developed by the original companies and available for purchase?
AKG— D112, C414, 451B and C12VR
Audio-Technica— 4033a, 4050 and ATM250
Electro-Voice— RE-20
Manley Labs— Gold Reference Tube
Neumann— KM184, M49, U47 FET, U67 and U87ai
Sanken— CU-41R