Thursday, July 9, 2009

Explaining microphone types, part three.

O.K. So far we have discussed what the three most common microphone types are. They are the dynamic microphone, the condenser microphone, and the ribbon microphone. We also discussed just what applications these types of microphones are useful for in the recording world.

We quickly went over the most common types of microphone polar patterns that are available on microphones, and a few of the useful applications of these polar patterns. The patterns were cardioid, hyper cardioid, omni, and figure eight.

What is left to discuss about microphones is getting the best possible sound out of a particular microphone. I am currently writing about the handling of microphones as in order to reduce any unwanted artifacts. I am also getting to the points of the “EQ-ing” possibilities of certain microphones.

Lastly, I wish to end off by summing up this three part series on a general topic of interest. This topic of interest is that I want to hit upon is “Just what microphones should every budget minded home recording enthusiast have in their microphone collection”?

So, lets talk about some proper microphone handling techniques.

We all want to get the best possible recording; using whatever microphones we have available to us. Sometimes using them to their best ability means setting them up correctly and thus reducing any unwanted sounds (artifacts) in our recordings. We also may have some choices to make concerning the microphones settings that alter the incoming sound to better match our expectations.

When handling microphones, the rule of thumb is do not handle them! Eliminating any microphone movement insures a clean and constant recording of our sound source. Using microphone stands and shock absorbing suspension systems (shock mounts) is very helpful when it comes to clean and steady recordings. After we have listened to the microphones different placement locations with headphones and found the place that sounds the best, plant your microphone firmly with a stand and a shock mount, if possible.

So what about this “Proxy” or proximity effect thing that we have all heard about? What is it, and how can we prevent it from happening to our recordings? What are the “high and low pass roll off” functions, and what are they for?

The proxy effect happens in directional microphones, primarily the figure eight and the cardioid microphones. The proxy effect is what we call the build up of booming bass noise that you can sometimes hear in our music, typically on (but not restricted to) the vocals. This boom type of noise comes from a building low frequency as we move a microphone closer and closer to a sound source.

Basically, we can do a few different things to avoid this build up of low frequency noise. The most obvious is to move the directional microphone further away from the sound source. But if the microphone is in the sweet spot, then “that aint gonna happen”!

Microphone designers have built some clever features that help us with this evil proxy effect. They are EQ-ing switches, basically, called low frequency roll off switches, or pads. When activated, this feature reduces the intake of the “boominess” that we so wish to avoid. Lastly, we can adjust our EQ-ing at the mixing board or at our DAW in order to cut the low end down to an acceptable level.

Sometime vocalists can sound, well, just awful! Every “P” seems to pop, and each “S” rings out with a hissing, shimmering high end distortion. By simply adding a pop-stopping filter to our microphone most pops can be avoided. Aiming our vocals into the microphone at a slight angle can remove a lot of hissing. EQ-ing and the use of wind screens can also help to reduce these common microphone phenomena’s.

Phasing issues.

“Phasing” is what we call a microphones recording that seems very hollow and flat. When we use two microphones to record one source (guitar, vocals, ect) phasing may occur. Think about a complete sine wave. Now double it. Phasing happens when the waves cancel out each other. This results in missing high and low end, and a nasal sound. Correct microphone set up and placement can all but remove any phasing issues that you may encounter. Check with the microphones manufacturer to see how a stereo set up should be put into action.

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