We believe that microphones must always serve their purpose well. This purpose is much more than just transmitting your signal. Microphones are constant companions of the musician: in the rehearsal room, in the studio, on tour. However, each technical area has got its own language. In audio engineering, it is particularly fierce. Thus, we would like to give you an understanding of the basics: clearly arranged and in plain language.
This article will include the basics of the following terms:
- Polar pattern: this is the direction into which the microphone can 'hear'
- Dynamic or condenser: this describes the operating principle used in a microphone
- Small diaphragm or large diaphragm: this is the 'eardrum' of the microphone
- Maximum sound pressure: this is how much the 'eardrum' of the microphone can withstand
Just like camera lenses pick up the image from a certain direction, sometimes wider, sometimes more focused, microphones also have a 'hearing direction', which we call 'polar pattern'. The most common polar patterns are cardioid, supercardioid and omnidirectional. There is still the figure-eight polar pattern, the broad cardioid, the hypercardioid and the lobar polar pattern which are rarely used in band practice.
The cardioid or supercardioid is the most important polar pattern for most musicians because most of the time there is exactly one direction from which our sound comes. As a vocalist we either sing directly into the microphone or the microphone is positioned directly in front of our sound source.
A cardioid microphone suppresses sound from the back and can 'hear' most strongly what happens exactly in front of and slightly to the side of it.
It is like this: the shape of the 'sound characteristics' which is drawn in 2D on a paper is similar to the shape of a cardioid (1st graphic). The supercardioid microphone takes the 'perky ears' of the microphone one step further: it prefers even more the sound that comes directly from the front. The angle at which the supercardioid microphone picks up sound is therefore narrower (2nd graph) but the rear sound is suppressed less than with a cardioid (important for positioning monitor speakers, keyword: susceptibility to feedback).
The cardioid and supercardioid are good if only a few ambient sounds are to be included in our signal. However, cardioids and supercardioids are unsuitable for applications where the surrounding area plays a role in the recording.
An example where the surrounding area plays an important role in the recording is a choir or orchestra in a large hall: in this case, the acoustics of the hall are part of the sound, the hall 'resonates' with it. Thus, a sound engineer would not only work with supercardioids, but rather 'take' the whole hall.
Nils Wittrock, singer and guitarist of The Hirsch Effekt: “I use live supercardioids because my microphone is stationary.”
I only use supercardioid microphones for singing. I do not have the microphone in my hand when singing because I also play the guitar. This means that I can always keep the same distance between me and the microphone (stand). This polar pattern is important for me because few other influences beside my voice should interfere. For this purpose, I use an 'Optogate'. It ensures that the microphone goes off when I am not standing in front of it. As a result, I hardly have any unwanted stage sound through my vocal microphone.
The omnidirectional polar pattern is suitable in case the sound comes from all sides. This is because an omnidirectional microphone picks up the sound equally well from all sides. The easiest way to record a demo is: put a microphone with omnidirectional polar pattern into the rehearsal room, plug it into the recording interface and start playing. Omnidirectional microphones are also well-suited for orchestras, choirs or a group of background vocals.
To keep it accurate, we also want to mention two polar patterns which are not commonly used for live applications: figure-of-eight and lobe.
- The figure-of-eight polar pattern is able to equally pick up in two directions, i.e. it is bidirectional. If you imagine a circle to illustrate 360° directivity, the lines of the number '8' cross in the centre of the circle. Thus, the figure-of-eight polar pattern picks up to the front and to the back but not to the left and right. This can be useful in orchestras. However, it rarely makes sense on a club stage.
- Even though the lobe polar pattern preferably picks up in one direction, it also picks up a little in the opposite direction. Thus, it is also bidirectional but very unequally distributed. Directional microphones feature a lobe polar pattern.
To explain the exact physical-electrical background here would unnecessarily lengthen this text. You are reading this text because you want practical information. This is what you should get:
usually have a better sound quality than dynamic microphones
- work in a wider frequency range and are rich in detail
have the highest pulse fidelity which means that with fast punches, i.e. a snare or bass drum, the sound does not 'smear'
need a current source/phantom power
usually have a lower maximum sound pressure. So look for a -10dB- or -20dB- attenuator on the microphone, it will get the job done
are very robust
tend to have less feedback
are usually cheaper than condenser microphones
Janosch Held, sound engineer: “There are many entrenched myths in the field of microphones”
It has become common knowledge that dynamic microphones are always vocal microphones and condenser microphones are used for the studio. No one questions that anymore. However, this assumption is wrong. Condenser microphones are great for vocals, especially with a large diaphragm (that is the little leaf which vibrates due to the sound and thus converts the sound waves into signals). It can also be used live, contrary to the wide spread preconception. They are just not as indestructible as dynamic microphones. For example, I have worked with live bands which turned their amps towards the stage wall and placed a condenser microphone in front of it. Then, the microphone is protected from other sound sources and stumbling musicians but still gives the fat condenser sound.
No matter whether dynamic or condenser, a general rule for good miking is: use as few stands as possible.
Stage microphones should neither wobble nor slip. So try to attach your microphones to the sound source using clips. Plug-in microphones for toms and snares show how it is done. This can also be done with amplifiers. Or for the hi-hat: I simply convert a clip thing from the handlebars of a bicycle which is used as a light. The microphones are then rigidly attached and the sound direction remains the same.
Nils Wittrock, singer and guitarist of The Hirsch Effekt: “Please bring your own microphone to the gigs, particularly as a singer.”
Most live clubs have their own microphones, usually dynamic ones. This is one of the absolute standard microphones which are usually lying around in live clubs. However, they have a serious disadvantage: it features a foam which both musicians and technicians do not clean often enough. This is done either never or at least not regularly. Not only is it unhygienic because 4,715 other singers have sung into it before you, it also changes the sound. Because dirty foam is tighter. The microphone becomes dull. High frequencies are lost. Test this in the rehearsal room with a new and an old, unkempt microphone. Especially when you sing melodically, there is a massive difference. In addition, it is simply nice if you do not just assume that someone on the spot will hand you a microphone. Therefore, if you care about your sound, bring your own microphone.
The difference between large and small diaphragm can usually only be found in condenser microphones. This can clearly be noticed: Small membrane mics look like small tubes, large membrane mics have a large basket. The difference can already be noticed in the name: One has got a large diaphragm, the other one features a much smaller diaphragm. What difference does this make in practical operation?
A small diaphragm microphone should provide a precise and clean sound. A large diaphragm microphone should provide a full and rich sound. In most cases, large diaphragms are therefore better suited for singing. However, with hard 'punches' like a snare, the sound pressure is often too strong.
One advantage of microphones with a small diaphragm is that they maintain their polar pattern more consistently over a wide frequency range. Even at very high frequencies (solo guitars) or very low frequencies (5-string basses), they maintain their polar pattern. However, they sound less 'full' or 'organic', but instead, they are very accurate, neutral and rich in detail. However, it is also a matter of taste.
Microphones with a large diaphragm are not as accurate with their polar pattern, i.e. they tend to be omnidirectional at low frequencies and increasingly directional at higher frequencies. But that is exactly why they make the voice or a solo instrument so natural and 'full-bodied'.
The maximum sound pressure is often an underestimated feature of microphones.
A lot of bands buy expensive microphones and distort their own sound by sound overload of the microphones.
Despite excellent technical features, the sound then remains mushy. In this case, microphones which can handle high sound pressure levels may help. However, you should always check the sound level in the rehearsal room or on stage. Thus, you are able to check if all used microphones can withstand this sound pressure. Otherwise, the sound will be bad and the reason for it will remain in the dark.
The world of microphones quickly seems more complex than it needs to be for most applications. Many differences between the microphones are minor details and are only important when it comes to highly professional studio recordings. As a general rule, you could say:
Rehearsal room recording with few microphones: a condenser with a large diaphragm or two dynamic microphones with cardioid polar pattern which are pointed into two different directions. Please check the maximum sound pressure.
Live performance with lots of movement: dynamic microphones, because more reliable.
Microphone for vocals: large diaphragm, supercardioid
Microphone is placed in front of the bass or guitar speaker: small diaphragm, supercardioid
Microphone is hanging over the drums: large diaphragm, also small diaphragm, cardioid or supercardioid
And that is exactly why the 'technology jungle' in the world of microphones should never stop you from trying out new things yourself. With all this advice, one thing is always for sure: you can do anything you want. In our article about DIY recording, we have asked our favourite artists why bands should record themselves more and what they need to do it.
Photos © The Hirsch Effekt