Firstly,
There are 5 basic directional patterns:
Omni
The simplest mic design will pick up all sound, regardless of its point of origin, and is thus known as an omnidirectional microphone. They are very easy to use and generally have good to outstanding frequency response. If you wanted to mic an entire room, perhaps band practice or something, with one mic, omni would be perfect for this.
Bi-directional (also known as "figure 8")
This is the way any diaphragm (I will explain diaphragm) will behave if sound can strike the front and back equally. The fact that the mic accepts sound from both ends makes it difficult to use in many situations. Most often it is placed above an instrument. * Personally I have never used a bi-drectional pattern. You may find it useful in some cases - especially if you dont have multiple mics.
Cardioid
This pattern is popular for sound reinforcement or recording concerts where audience noise is a possible problem. Now, the point of a cardiod pattern is to pick up sound from directly where it is pointed. The reality is that the pattern is not entirely directional, and you will still pick up sound from the rear of the diaphragm, especially low frequencies.
Regardless, a cardiod pattern is the most usefull for studio operations. Whether it be a guitar, vocals, drums, whatever.. a cardiod will usually work best for you. Its unidirectional and isolates your target, rejecting most unwanted noise.
Supercardioid
A polar pattern name used to describe the pickup pattern of some microphones. The Supercardioid pattern is very similar to, and often confused with, the Hypercardioid pattern. The Supercardioid pattern is slightly less directional than the Hypercardioid pattern, but the rear lobe of sensitivity is also much smaller in the Supercardioid .
Hypercardioid
A polar pattern name typically used to describe microphone pick up characteristics. Hypercardioid patterns are similar to Cardioid and Supercardioid patterns in that the primary sensitivity is in the front of the microphone. They differ, however, in that the point of least sensitivity is at the 150 - 160 and 200 - 210 degree positions (as opposed to directly behind the microphone in a Cardioid pattern). Hypercardioid microphones are thus considered even more directional than Cardioid and Supercardioid microphones. Hypercardioid microphones are frequently used in situations where maximum isolation is desired between sound sources.
*the only time I've ever used Hypercardiod is on a film set with a Shotgun mic. The Hypercardiod pattern is very directional, and you can pick up a conversation 30 yards away if you point the mic directly at the person's mouth. However, you have to be careful.. as you can see, the Hypercardiod pattern picks up sound at 180 degrees.
Okay now we have a basic grasp on different directional patterns. Maybe later we will talk more about a "stereo pair" (basically, this is acheived by placing 2 cardiod mics next to eachother, and angling them so you have 180 degrees of peak signal. Label one Left, and the other Right, and you can mic something in stereo.. like an orchestra for example)
A quick list of mics:
The all time favorite:
The SM58 has a dynamic cardiod pattern. It is unidirectional, ruggedly built, it isolates sound pretty well, and shit, you can mic just about anything with this thing. If you can only buy one mic, and you are broke as fuck, buy this one. It is used for live vocals 99 times out of 100.
SM57:
Much like the 58, the 57 has a slightly wider frequency response, and is usually used for micing instruments like guitars, snares, and bass. The 57 is a touch more directional than the 58, and its "hotter". Its not quite as warm, and does best when placed close to the signal.
SHURE KSM44
I love this goddamn thing. So this mic has an even wider frequency response - 20hz - 20khz (it is said that the human ear cannot process anything lower than 20hz or higher than 20khz.. you will not encounter those frequencies).
The main difference between this (a "studio condenser") and a mic like the 58, is that the KSM has a Large Diapragm. This enables the mic to pick up more sound, and reproduce it much more accurately, although its a bit more fragile. Also, it requires Phantom Power.
This mic can be set to Omni, Cardiod, and Figure 8 patterns. It is great for vocals, instruments, or pretty much any miking situation.
Okay yall those are the basics..
Any questions?
