The Music Espionage

Manufacturers Specifications – Microphones



Manufacturers Specifications – Microphones: So you now have a better understanding for the basics of electricity, cover in ‘Manufacturers Specifications –Electronics’. Lets now take that and use on maybe the most common piece of equipment in any recording studio…the microphone. Manufacturers Specifications –Microphones will cover the most common specifications listed on the back of any microphone box. After that you will not need to look at these cross-eyed no more, you will know it all! Well hopefully.

Manufacturers Specifications – Microphones – Basic Example:

The image below was taken for the sE Titan microphone, an upper-mid range microphone, in the price brackets of around £250 for just the microphone, but that does include a wooden hard case!! So lets work through all the spec shown.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: sE Titan

 

Operating Principle:

This describes the type of transducer that a certain microphone uses to converse sound into an electrical signal. The mechanical vibrations of the diaphragm are converted into an electronic signal by the transducer. All microphones are transducers, changing one form of energy into another. If a microphone changes acoustic energy (sound-waves) into electric, then a speaker does the same but in reverse. The two most common transducer types you will certainly have heard of many times before; these are Dynamic and Condenser.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Operating Principle

 

Polar Pattern:

The Polar Pattern is a really important aspect when selecting any microphone. This defines how the microphone reacts to sounds coming from different directions. It indicates how sensitive it is to sounds arriving at different angles about its central axis. The directional response of a microphone is recorded on a polar diagram, shown below.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Polar Patterns sE Titan

This polar diagram shows the level of signal pick-up (sometimes shown in decibels) from all angles and at different frequency ranges. For example, a mic can be very directional at one frequency (usually higher frequencies) but virtually omni- directional at another. A microphone’s polar response pattern can determine its use- fullness in different applications, particularly multi-microphone settings where proximity of sound sources makes microphone leakage a problem.

Find out more about in microphone polar-patterns in our post, ‘Quick Guide to Polar Patterns’.

Quick Guide to Polar Patterns

The image below is from a Shure SM57 microphone. You can see that at low frequencies the microphones is basically Omni-direction in its polar patter. However as the frequencies get higher (the right graph) the directional properties become more Cardioid and even Hyper- Cardioid. You can find out more about the different polar patterns here – Microphone polar Patterns.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Polar Patterns SM57

 

Frequency Response:

This fundamentally shows the range of different sounds the microphone can re-produce and how faithful it is to those frequencies from low to high pitch sounds. The Frequency response is shown as a graph with the frequency across the bottom and amplitude going from bottom to top. A microphone that is said to have a flat frequency will have a response equally sensitive to all frequencies, so it reproduces vocals and instruments with little to no extra “colour” and it is very close to the original sound. A typical flat response is shown below. These are usually best for recording vocals and acoustic instruments.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Flat Frequency Responce

A microphone with shaped response will be more sensitive to some frequencies ranges than others. This could be greater sensitivity in the upper-mids, this would be great for lead vocal recordings and electric guitar amplifiers. Or might have de-sensitivity to low frequencies will reduce mains-hum, room noise and decrease the proximity effect.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Shaped Frequency Response

 

Sensitivity:

Microphone Sensitivity, in plain terms, is the magnitude of the volume of sound that a microphone can record for a given signal; basically, it’s the “loudness” of the sound that the microphone can pick up. A certain level of sound is played from a source and the microphone records this signal. The amplitude, or intensity, of the signal that the microphone can record is the sensitivity, or gain, of that microphone.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Microphone Sensitivity Graph

The loudness, or sensitivity, is measured in volts, usually millivolts. The sensitivity tells us how much electrical output (in millivolts) a microphone produces for a certain sound pressure level at a certain frequency. So the higher the number shown here means the more sensitive the microphone is. However, this number is useless unless you know what the Decibel (dB) level was that it was tested against. This is normally going to be 94dB or 1 Pascal.

Manufacturers Specifications – Microphones

Manufacturers Specifications – Microphones: Microphone Sensitivity

 

Impedance:

This is where the last tutorial comes in (Guide to Manufacturers Specifications – Electronics ). Impedance tricks so many people, but it’s really simple. It is basically the amount of Resistance, how much the circuits of the microphone slows down the flow of the electric current while it travel through. Just like Resistance it is measured in Ohms (Ω).

 

The golden rule is the LOWER THE IMPEDANCE THE BETTER.

  1. Low Impedance (less than 600 Ω)
  2. Medium Impedance (600! – 10,000 Ω)
  3. High Impedance (greater than 10,000 Ω)

 

High impedance microphones are usually quite cheap. Their main disadvantage is that they do not perform well over long distance cables – after about 5 or 10 meters they begin producing poor quality audio (in particular a loss of high frequencies). In any case these microphones are not a good choice for serious work. In fact, although not completely reliable, one of the clues to a microphone’s overall quality is the impedance rating. Low impedance microphones are usually the preferred choice for professionals.

 

 

Output Connector:

Finally, this is really simple the type of cable used to connect to the microphone. 9 times out of ten with microphone this will be the industry standard XLR cable.

 

 

Here are the other Manufacturers Specifications tutorials;

Part One: Manufacturers Specifications – Electronics

Part Two: Manufacturers Specifications – Microphones

Part Three: Manufacturers Specifications – Interfaces