There’s almost more manufacturers of microphones than you can shake a stick at.  Top brands include Shure, Neumann, AKG, Beyer-Dynamic, Telefunken, Aston, Behringer, etc, etc, etc.   Wikipedia has a list of more than 60 of the common brands here.   So there’s plenty of mics around.   The learning points  during the course were what do they do and how should they be used? 

 

Mics can be split into 3 main types: Dynamic; Condenser; Ribbon and within each type further split by their polar patterns.

 

Dynamic Mics

These are the most common type of mic as they’re cheap to produce and robust.  They don’t need any power/voltage fed to them to make them operate.  So they can be used anywhere, live or in the studio.  Possibly the most recognisable dynamic mics are the Shure SM58 and the Shure SM57.  A disadvantage of dynamic mics is that they have a slightly lower frequency response at higher frequencies than either condenser or ribbon mics.  

 

Condenser Mics

These require a power (48Volt) feed to them making them less flexible than dynamic mics.  The benefit of them is that they have a wider and often flatter frequency response than dynamic mics.  They can be split into tow by the size of the diaphragm.  Large condenser mics and Small condenser mics.  Small condenser mics are often referred to as Pencil mics.    The best known and most recognisable condenser mics are probably made by Rode or by Neumann.  These are the mics you see in photos of artists in recording studios where the mic is in a cage, often hung pointing downwards.

 

Ribbon Mics

Less common as they are inherently fragile.  They produce a similar response to condenser mics but are known for having a ‘warmer’ tone. 

Polar Patterns

This is the term given to the zone or area around it where the microphone will pick-up sounds.

1.Omnidirectional

Sound is picked up equally from all directions around the mic.  

2.Bi-Directional – Figure 8

Sound is picked up from the sides (or front and back) of the mic.  It’s commonly used with the “Mid/Sides” positioning technique

3.Cardioid

Shaped like a heart, hence the name.  This is the most common polar pattern.  99 out of 100 mics in common use will be this pattern.  It means the mic picks up sound on axis from the direction in which it’s pointing.  It doesn’t pick up sound behind it.

Mic Techniques

Mid/Side technique

Also known as Blumlein technique after the early pioneer of this technique.  In this technique two mics are used.  One, a cardioid pattern will point at the sound source with a figure of eight pattern mic set as close as possible to it to pick up side signals.  This is then used to produce a wide stereo image of the sound source.   You don’t need to have matched mics for this, indeed you can mix dynamic and condenser mics. It’s the polar patterns which matter. 

I used Mid/Sides within my multimedia project “Connected” as a technique for the ambient wind sounds throughout the film.  Using this allowed me to treat the ‘sides’ differently from the ‘mid’ and create a more complex soundscape.  I applied a subtle flange to the sides, but not to the mid. 


Universal Audio has an excellent article on Mid/Sides – here.

How Mid/Sides looks in terms of pickup area.
A pair of Aston Spirit mics configured for mid/sides recording. Not much to see is there? One mic is set as cardioid and the other (top) as figure of 8)

X-Y or Coincident Pair

An easy technique to use.  X-Y (coincident) stereo micing consists of using two microphones that are placed right next to each other so that the diaphragms are as close together as possible without touching one another. X-Y stereo micing is the most common type of stereo microphone setup and the one that you’ll likely use if you do stereo micing.  It gives a stereo image, but not as wide an image as other techniques do.   The image below shows my behringer C2 small diaphragm condenser mics set up in this configuration

X-Y configuration. 90 degrees and capsules almost touching.

Spaced – A-B

This is what it says on the tin – mics spaced out. Spaced-pair stereo micing involves placing two microphones at a distance in front of the instrument(s) that you want to record and at a distance from one another. This approach can work well if you record an ensemble that takes up a lot of room. The illustration shows a top view of a typical spaced-pair stereo mic setup.  There’s a risk with this that there may be phase problems if you don’t space the mics properly. There is however a general rule which helps minimise this. It’s called the 3:1 rule, this guideline says that you should place the mics three times farther apart than they are from the sound source.

ORTF technique

The technique is basically a combination of the previous two.  The microphones are physically spaced apart, approx. 17cm, like with A/B recording, which will yield a wider stereo image.  Then it uses directional mics, like with X/Y recording, so it should pick up less of the ambient room sound. The image below shows my Behringer C2 small diaphragm condenser mics set up in this configuration.

ORTF configuration. Approx 110 degrees and 17cm apart.