PREVIOUS | MAIN PAGE |
for your Home Studio...
Microphones convert the
sounds you hear into electrical signals that can be recorded onto tape
or hard disk. Choosing the right mic for the job at hand is
critically important to getting the sound you want on your final
tracks. No amount of EQ, compression or reverb can change the subtle
signature that each particular microphone leaves on your audio tracks.
So, how do you choose
that perfect mic without first buying and auditioning everything on the
market? A good first step would be to familiarize yourself with the
basic microphone types:
The term "Omnidirectional"
describes a type of microphone that picks up sound equally from all
directions. Omni mics tend to have very good bass response, without
the artificial low frequency boost provided by the 'proximity
effect' of a typical cardioid mic (see below). Really good
omnidirectional condenser mics are great at capturing a sense of
'open space' and 'air', which makes them the first choice for
critical reproduction of acoustic instruments in good sounding
acoustic spaces, such as symphonic orchestras, vocal choirs, pianos
or string quartets in concert halls.
You can also use
omnidirectional microphones to 'close-mic' an instrument or vocalist
without worrying about the artificial bass boost caused by a
directional mic's 'proximity effect'.
Some of the highest
fidelity mics available are of the omnidirectional condenser type,
such as mics from Schoeps, DPA (B&K) and Earthworks. A common use
for dynamic omni mics is in TV and radio reporting (known as
Electronic News Gathering or "ENG"), where you want to capture
environmental sounds along with the reporter's voice.
back to top
microphone is more sensitive to sounds directly in front of it than
to sounds 90 degrees off to either side (when plotted on a graph the
response pattern looks heart-shaped, hence the name). A mic with a
cardioid pattern is even less sensitive to sounds directly behind it
— in fact, cardioid mics practically cancel pickup of sounds
emanating from directly behind the mic. This makes cardioid mics
very useful for sound reinforcement (P.A.) and live recording use,
as well as the most popular choice for use in the imperfect
recording environment of most home studios. To use a cardioid mic,
simply aim the mic at the instrument you want to record, and the
rest of the stage sound will be at least somewhat quieter than the
desired instrument's sound.
There are a couple of
variations on the cardioid pick up pattern. Supercardioid and
hypercardioid mics are less sensitive to 90 degree off-axis sources
than plain cardioids, meaning that they will do a better job of
rejecting sounds from off to the sides. However, hypercardioids do
pick up some sound from directly behind the front of the mic, making
them a little bit like a 'figure-eight' mic (see below).
Cardioid mics exhibit
a characteristic called the 'proximity effect'. The closer a sound
source is to a cardioid mic the more the mic will accentuate that
sound source's bass frequency output. This can add richness and
fullness to a singer's voice or to a saxophone's sound, but it can
also muddy the sound of a guitar amp or acoustic bass. When miking
from a distance, cardioid mics have a tendency to sound somewhat
thin in the bass when compared to omnidirectional mics. For this
reason, cardioid mics are usually used for close-miking (with the
mic placed less than two feet from the sound source), while
omnidirectional or figure-eight mics are usually used when miking
from farther away.
back to top
have the open sound and good bass response of omnidirectional mics,
with the added advantage that they reject sounds coming from either
side of the mic. Since figure-eights pick up sound equally well from
directly in back and directly in front, care should be taken that
you don't capture undesirable reflections from low ceilings or
nearby walls. A good place to use a figure-eight pattern mic is when
you need to cancel reflections from side walls in a narrow-ish room
but you still want to capture a good sense of room ambience.
back to top
Dynamic mics use a
'moving coil' to sense the changes in air pressure that make sound
waves. The wire coil is connected to a thin diaphragm, and the whole
assembly is suspended over a permanent magnet. When moving air hits
the diaphragm it causes the coil to move over the magnet, which
causes a process called electromagnetic induction to take
place. This causes an AC voltage to be formed that is an electrical
'analogy' of the original sound. The electrical signal that appears
at the mic's output is a more or less faithful reproduction of the
original vibrations in air, only in fluctuating AC voltages instead
of air pressure changes.
diaphragm dynamic microphones
These are by far the
most commonly used mics for P.A. and stage sound use. Dynamic
microphones are typically very rugged and don't require a voltage
source to work properly. Cardioid pattern, small diaphragm dynamic
mics are most often used as handheld vocal mics (like the very
common Shure SM-58) or as instrument mics (like the equally common
Shure SM-57). There are many other similar dynamic mics from
companies like Audix, Electro-Voice, Sennheiser and others.
SM57 (left) and the SM58 (right):
These are the most commonly used small-diaphragm
diaphragm dynamic microphones
While similar to
their small diaphragm cousins, large diaphragm dynamic mics are
typically used for very loud, bass-heavy instruments such as
tom-toms, kick drums, and bass amp speakers. The larger diaphragm
allows these mics to withstand higher Sound Pressure Levels (SPL's)
with ease, which allows low-distortion reproduction of very loud
instruments such as trumpets, trombones and electric guitar
amplifiers. However, the larger diaphragm will also have a higher
moving mass, which can limit the high frequency response and
transient response of the mic.
Some popular large
diaphragm dynamic mics are:
RE-20 - A favorite of radio announcers and a good mic for kick
Shure SM-7 -
Similar to the E-V RE-20
- Commonly used on tom-toms and hand percussion, but also works
great on horns, kick drums and guitar amps.
A large-diaphragm dynamic microphone used for
broadcasters and voice-overs, as well as for miking
kick drums, brass and bass instruments.
back to top
capture sound using a conductive diaphragm with a capacitative
charged plate behind it. The charge is supplied by a DC voltage
source from a battery or from the 48 volt 'phantom power' supply
present in most mixers and mic preamps. Air pressure changes meeting
the conductive diaphragm cause it to move, which causes an analogous
AC voltage to be formed in the charged plate. These tiny AC voltages
are sent to a tiny preamp built into the microphone, which brings
the signal level up to where it can drive a typical microphone
preamp. The signal leaves the microphone through the cable and on to
the microphone preamplifier stage of the mixer. Because the
diaphragm of a condenser mic can be made very thin and light,
condenser mics tend to be more accurate and 'faster' than dynamic
mics, especially in the midrange and treble frequencies. However,
condenser mics tend to be more physically delicate than dynamic
mics, so they are more commonly used for studio recording than for
live sound and P.A.
Since condenser mics
need a tiny amplifier built into the mic casing (called the "head
amp"), the quality of its electronics will influence the sound of
the mic. Some condenser mics use a small vacuum-tube circuit for
their head amp, along with an external power supply box for the
electronics. This is what is referred to as a "tube mic."
diaphragm condenser microphones
condenser mics have the best high frequency response and quickest
transient response of all the commonly available microphone types.
For this reason, these mics are most often used as drum set overhead
mics (to faithfully capture cymbals and stick attacks), for acoustic
stringed instruments like guitars and violins, and for percussion
instruments like vibraphones, shakers, and marimbas. Another common
use for small diaphragm condenser mics is as stereo pairs for
ambient pickup of acoustic events in good sounding spaces. The one
downside to small diaphragm condensers is that they tend to have
more self-noise than other types of microphones.
Some popular small
diaphragm condenser mics are:
AKG C 451 -
The "classic" small-diaphragm condenser mic. An old favorite on
piano, acoustic guitar and as drum kit overheads.
- A truly professional recording mic, used in the best studios.
- A newer professional mic with extremely accurate frequency and
Shure SM-81 -
Very flat frequency response; commonly used on acoustic guitars and
as drum kit overheads.
AT-3528 - A cardioid model that is sort of a 'poor man's KM-84'.
AKG C 1000 S -
A good all-around budget favorite.
- From Russia, this is another mic made to be similar to the KM-84
but for a lot less money.
KM-180 series small diaphragm condenser microphones
are highly regarded by recording professionals.
diaphragm condenser microphones
Since condenser mics
are intrinsically more sensitive to higher frequencies, it's
possible to combine the warmth and fullness of a large diaphragm
with the high frequency detail typical of small diaphragm condenser
mics into a single microphone. These large diaphragm condenser mics
are the mainstay of recording studios everywhere, especially for
recording vocals, pianos, horns and other acoustic instruments. Some
older vacuum tube based large diaphragm condenser mics, such as the
Neumann U47, U67 and AKG C12, are collector's items prized for their
sonic warmth and smoothly accurate reproduction of aural details.
The Neumann U87 (introduced in the mid-1960s) is an FET-amplified,
large diaphragm mic that has become a modern classic.
Some popular large
diaphragm condenser mics are:
AKG C 414 B-ULS
- An industry standard for overhead drum miking and general use;
provides choice of cardioid, hypercardioid, omni, and figure-8
Neumann U87 -
The industry standard; provides choice of cardioid, hypercardioid,
omni, and figure-8 pickup patterns.
Neumann TLM 103
- A new, lower-priced version of the famous U87; cardioid only.
AKG C 3000 B -
A budget mic based on the design of the venerable C 414 B-ULS;
AT-4033a - An early '90s design that proved to be a huge hit.
Now that its price has been lowered, the AT-4033 is once again a
great value. Cardioid pattern only; great on saxophones.
U87 is the 'gold standard' of large diaphragm condenser
microphones, used in major recording studios around the
A quick note about
Chinese-manufactured large-diaphragm condenser mics:
A company in the
People's Republic of China, 797 Audio, has been making copies of
popular Western-made microphones for many years now. These are such
obvious copies that international copyright law prohibits selling
them in Europe and North America. However, several Western companies
have been working with 797 Audio to have their own designs made in
China and then sold in the West. Most of these mics look almost
exactly like the Neumann U87 and are claimed to sound 'just like the
real thing, but for a fraction of the cost' — the Nady SCM 900, Joe
Meek JM47 Meekrophone and Marshall Electronics MXL 2001-P are good
examples. Of course, there ain't no such thing as a free lunch. I
own an MXL 2001-P, and while I think it is a good mic for $150, I'd
say it sounds more like a caricature of a U87 than the real thing.
The MXL 2001-P's proximity effect is not well controlled, so male
voices come out with a 'woofiness' in the low end if you work the
mic too close. The high frequencies are more 'sizzly' than 'silky,'
but I wouldn't say that the MXL mic sounds bad. It just sounds like
a good cheap mic with a 'scooped out' midrange response, sort of how
a mic sold at your local Radio Shack might sound if it was designed
to 'sound like a Neumann.' In the end, I would say that $150 is just
a little too much for the MXL 2001-P, but for $100 it would be worth
it for many people. (Note that the Nady SCM 900 looks identical, and
both the Nady and Marshall mics have been dropping in price.) I
would say that an MXL 2001-P certainly beats a Shure SM58 or SM57
for recording vocals, piano or acoustic guitar, but if you already
own a CAD, RØDE, AKG or other inexpensive condenser mic, don't think
that you're missing out on anything.
Bear in mind that not all mics made by 797 Audio sound 'cheap.' The
slightly more expensive Marshall Electronics MXL 2003 sounds
noticeably smoother than the MXL 2001-P, and reviewers are
positively gushing over the Studio Projects C1, C3 and B1
microphones (designed in the USA, made in China).
There are some good-sounding Russian-made condenser microphones
available for almost as low prices as the mics made by 797 Audio.
The Oktava MC-219 is an old 'sleeper' favorite.
The above are my own opinions, so feel free to apply your own
personal grain of salt. Some reviewers have written that the MXL
2001-P is an unbeatable bargain, while others (especially at
ProRec.com) have lambasted almost every Chinese-made mic as
shameless (and lousy-sounding) scams. As you can see, I've taken the
back to top
When a wafer-thin,
small aluminum ribbon is suspended between two mounting points
inside a strong magnetic field, you get a microphone that is
extraordinarily sensitive to vibrations in air (sound). Ribbon mics
can really capture the thump of a plucked acoustic bass or the
subtle dynamics of jazz drums. Unfortunately, ribbon mics tend to be
extraordinarily fragile—blow on the ribbon the wrong way and you can
stretch it out beyond repair. Nevertheless, ribbon mics remain a
favorite of recordists everywhere.
Some common ribbon
RCA BX-44 and
BX-77 - The original classics.
Coles 4038 -
The standard in modern ribbon mics.
- A budget ribbon mic; hypercardioid only.
Royer Labs R-121
- A new ribbon mic design that is getting a lot of attention.
4038 (left) is the standard ribbon microphone
used by the BBC for recording and broadcast.
The Oktava ML-52 (right) is a new ribbon mic from Russia.
back to top
By combining two
cardioid condenser elements into one chassis, a single point stereo
microphone can be made. The most common is the X-Y type, where the
two cardioid elements are pointed away from each other at a 90
degree angle. Some stereo mics are of the Mid-Side (MS) type, using
a combination of a forward-facing cardioid element with
sideways-oriented figure-eight element, which allows for remotely
controlled adjustment of the stereo image width.
Some common stereo
VP88 is a single-point stereo microphone commonly used for
back to top
Recording the human
singing or speaking voice presents some unique challenges. Most
people prefer a heightened sense of 'presence' on voices, and will
often also prefer a mild bass boost for added 'warmth'. As a result,
most microphones meant for recording or amplifying vocals have a
'tailored' response characteristic.
vocal microphones are designed to be very sturdy and produce as
little handling noise as possible. They are also designed with a
very 'tight' cardioid or hyper-cardioid pick-up pattern, so that
there is less 'bleed' from other instruments on the stage.
The standard mic of
this type is the Shure SM58. It can withstand very rough
treatment and has very good feedback rejection, making it perfect
for daily use on stages where amplified rock/pop/r&b/jazz bands
play. The SM58 has a specially-tailored response that reduces bass
pickup from far away (minimizing 'booming' from the stage sound) but
will boost the bass when the singer comes in close (creating a big,
warm sound). The SM58 also has a substantial peak in its response
from about 2kHz up to about 12kHz, which adds a pleasant 'sheen' and
overall brightness to the sound. This helps vocals cut through a
dense mix with clarity and intelligibility.
usually tell if a microphone is designed for live sound
vocal use if it is equipped with a pop filter to protect the
from blasts of air and plosive sounds ("p", "b" and "k"
The Shure SM58 pictured at left has a spherical, metal
pop filter lined with foam rubber on the inside.
Microphones for Recording Vocals – Large-diaphragm condenser
microphones like the Neumann U87 or AKG C12 are
typically used for recording vocals in recording studios. Like
handheld stage mics, these microphones also have a presence peak and
proximity effect tailored to enhance the sound of the vocalist.
However, because these large-diaphragm condenser microphones are to
be used in the more controlled environment of a recording studio,
they can have 'wider' cardioid pick-up patterns, allowing for a more
A recording engineer
will pick his microphones like a musician picks his instrument — a
'darker' mic will help tame a high, shrill voice while a clearer,
brighter sounding mic will help the vocal cut through a dense mix.
There is no single 'best' microphone for all situations — only a
palette of good microphones from which the recording engineer has to
choose the right tool for the job at hand.
large-diaphragm vocal mic is the Neumann U87, while some
prefer the vacuum-tube based Neumann U47. These microphones
have a distinctive upper-midrange to treble boost (presence boost)
and a warm, rich bass-boost from proximity effect. Similar mics to
the U47 and U87 are the AKG C12 and C 414 B-ULS, which
have the crisper sound characteristic of AKG microphones in general
(which some engineers love and others hate).
There are many
less-expensive versions of these microphones on the market today.
Here is a partial list:
Studio Projects B1
condenser microphone is used to record a vocalist,
the engineer will often hang a pop screen in between the
and the microphone to keep loud 'p', 'b' and 'k' sounds from
overloading the mic's pickup and spoiling a take.
back to top
There are many
different kinds of instruments, so different kinds of mics are used.
When recording acoustic instruments for classical music, the signal
from the microphone should be as faithful as possible to the
original sound. However, instruments used in rock and pop music can
be very loud and require a microphone that can withstand extremely
high sound pressure levels without distorting. It is extremely
difficult to make a microphone that is both sensitive enough to pick
up the subtle nuances of a fine acoustic instrument while also being
able to capture the brute force of a rock kick drum or a Marshall
stack without overloading. Since there is no single 'best'
microphone for all situations, it becomes necessary to choose the
best tool for the job at hand.
Microphones for loud sounds such as rock drumset, guitar amplifiers
and close-miking of brass instruments – There are a select few
dynamic microphones that are both rugged and have a smooth sound
suitable for recording high-decibel musical instruments. These
microphones are typically more expensive than dynamic vocal mics
(over $350) and do not work as well as condenser mics on instruments
with complex high-frequency information. The Sennheisser 421
and 422 and Beyerdynamic M88 are among the most widely
used dynamic instrument mics. The Electro-Voice RE-20 is also
popular. The Shure SM57 is frequently used on snare drums,
hand percussion (congas, bongos, timbales, etc.) and guitar
amplifiers, but not usually for bass-heavy instruments like kick
drum or electric bass. You will usually see dynamic microphones used
for live stage performances, while condenser mics are more often
used in the recording studio.
Microphones for Recording Instruments - When a higher level of
fidelity is required, especially in the recording studio, condenser
microphones will often be used. Again, the type of microphone must
be chosen to match the sonic characteristics of the source to be
instruments and Ensembles – Acoustic stringed instruments and
classical music ensembles will usually be recorded with sensitive
condenser microphones with relatively flat frequency response. It's
generally acknowledged that small-diaphragm condenser mics such as
those from DPA, Schoeps and Earthworks provide
the most accurate response, while some prefer the pleasant-sounding
coloration of the large diaphragm Neumann M50 or similar.
Individual Acoustic Instruments – When recording an individual
brass, wind or reed instrument for a pop or jazz recording, a large
diaphragm condenser microphone such as a Neumann U87 or
AKG C 414 B-ULS will often be used. If recording a featured
'solo', the instrumentalist is treated similarly to a vocalist—the
microphone may be chosen as much for its desirable colorations as
for its clarity, warmth, headroom, lack of distortion, etc.
Miking Piano -
Acoustic piano is treated in several different ways, depending on
the style of music and the sound quality desired.
For solo piano or
classical music, the piano is usually miked from a considerable
distance, with careful attention paid to the quality of room
acoustics and the degree to which the microphones pick up the
ambient sound of the room compared to the more direct sound of the
piano. Often an X-Y stereo pair of condenser mics will be used.
For rock, pop or
jazz piano in a group, the piano will usually be miked much
closer, often with the lid closed and the piano isolated from the
room sound with sound-absorbing blankets. For a robust, rich sound
choose large diaphragm condenser mics; for a brighter, clear sound
choose small diaphragm condenser mics.
Drum-Set - For rock and pop, the various pieces of the drumset
are miked individually. This allows greater freedom in the mixdown
phase to alter the sound to taste.
Snare Drum -
The most common technique is to place a Shure SM57 so that it
picks up the sound from the batter (top) head. Sometimes a second
microphone is placed underneath the drum to pick up the sound of the
snare wires. The output from this microphone may need to be reversed
in polarity so as not to introduce phase cancellations with the
signal from the top snare mic.
Kick Drum -
Depending on the sound of the kick drum itself, a large diaphragm
dynamic mic such as an E-V RE20 may be placed close to the
center of the front head, or inside the drum (if the front head has
a hole in it or has been removed). Experimentation with placement
will be necessary to achieve the desired sound.
Cymbals - In
most cases a stereo pair of condenser microphones will be placed at
least two feet above the kit to capture the sound of the cymbals
(and the overall sound of the drumset). Where it is desired to
capture the sound of the tom-toms with the overhead mic pair, it is
usually best to use large diaphragm condenser microphones for the
task (the AKG C 414 B-ULS works well here). If the tom-toms
will be close-miked, it is usually best to use small diaphragm
condenser mics so that the low mids don't build up to an unusable
degree. Suitable small diaphragm condenser mics include the AKG
C1000S, Audio Technica AT-4041, Neumann KM-184 and
Tom-Toms - If
desired, the individual tom-toms can be close-miked with large
diaphragm dynamic microphones such as the Sennheisser 421.
Small, clip-on condenser mics are also used (such as the Shure
Beta 98). Take care to place the microphones so that they will
not cause phase cancellations or introduce excessive 'bleed' between
Way - In the 1950s and '60s, drumsets were often miked with only
two microphones, one a couple of feet or so in front of the kit, the
other a couple of feet overhead and pointed at the snare drum.
Ribbon mics like the RCA BX-77 or Coles 4038 were
often used, as well as the newer large diaphragm condenser mics like
the Neumann U67. While you will not get a stereo spread with
this setup, you can get a very accurate picture of the acoustic
sound of the drumset. This can be a very effective technique for
making live recordings of jazz groups.
IF YOU MUST
CHOOSE ONLY ONE MICROPHONE...
If you are recording
your parts one at a time, overdubbing track by track in order to
build up your production, you may be able to get away with only one
microphone. As you can tell from the information you've just read,
there really isn't one microphone that will be best for all the
instruments you may need to record, in addition to your vocals.
In order to make the
decision easier, you will need to prioritize. Usually the vocal is
the single most important element in the mix. Therefore, it's
probably best to get a microphone that complements the vocals.
Usually this will be a large-diaphragm condenser microphone (see
above). If you can afford a multi-pattern mic like the AKG C 414 B-ULS
or the Neumann U87ai, you will have more flexibility in choosing the
sound that best fits the source. However, a fairly neutral sounding
cardioid-only condenser mic can work well on a wide variety of sound
sources. Be sure to experiment with mic placement to get the best
When placing cardioid-patterned
microphones on a stage or in the studio, remember the 4-to-1
rule—each microphone should be at least four times as far from the
next one as it is from the sound source. For example, let's say you
have a saxophone player and a vocalist standing next to each other
on a stage. Let's now assume that the vocalist will be singing up to
six inches away from her microphone, and the saxophonist will be
playing up to a foot away from his mic. Since the maximum distance
between the sound source (the vocalist and the saxophonist) and
their respective microphones will be one foot, the 4-to-1 rule
dictates that the two microphones (and the two musicians) should be
placed no less than four feet from each other. Placing the
microphones any closer together will likely result in excessive
off-axis bleed from one mic to the other, resulting in nasty
sounding comb-filter effects when you mix the sounds together. When
using microphones with wider patterns, you will need to keep them