What Is A Parabolic Microphone?
If you are interested in microphones you may want to know a little more about the parabolic microphone. A parabolic microphone works pretty much the same way as parabolic radar antennas. They are rather impractical for some things like hearing aids because they are too large. They do work well for specific needs.
A parabolic microphone collects sound energy coherently from a large area and the collection area is the cross-sectional area of the parabolic dish. The potential gain of a parabolic microphone depends on wavelength and frequency.
Because of the shape of the parabolic microphone the coherent summation of the rays is guaranteed. Each ray arrives parallel to the parabolic microphone axis and travels the same total distance. When sound rays strike a parabolic microphone from other directions sum incoherently. Because of this a parabolic microphone that is aimed or steered is preferred.
A parabolic microphone may not work well at low frequencies because the gain is low. The gain may be low because of its limited size in wavelengths. The parabolic dish may also be a factor if it is not a good sound reflector at low frequencies. The surface density needs to be very high for the sound deflector to work well. You might need about 2 pounds per square foot for the low frequencies of music. You will need much less for recording birdsong or speech.
You can use a parabolic microphone for many different things. A parabolic microphone has unusually focused front sensitivity and can pick up sounds from quite a distance. If you are interested in nature recording a parabolic microphone may be the best choice. Many people who enjoy bird watching use a parabolic microphone. A parabolic microphone is also used for outdoor sporting events where a specialized microphone is needed.
The parabolic microphone can be used for those in law enforcement and unfortunately they are available for those in the private sector who may use this type of microphone for eavesdropping. Some of these uses are nor encouraged nor are they legal. A parabolic microphone is often the choice for those who are involved in espionage.
Usually a parabolic microphone is not used for standard recording purposes. This is because a parabolic microphone tends to have poor low-frequency response as a consequence of their design.
A parabolic microphone will come in handy for certain uses, in fact it is the best microphone in some instances. Before you buy a parabolic microphone you will want to know that it is the type of microphone you need.