How do microphones

The third type of microphone is called a condenser microphone. It contains the same parts but the diaphragm moves the metal plates of a capacitor instead of moving the coil as in the Dynamic microphone. A capacitor is two metal plates in close proximity to one another.

Microphones may be omnidirectional or unidirectional. If you are recording something while there is ambient noise all around you it may be better to go with a unidirectional microphone as it picks up sound from only one direction. If you need your microphone to pick up sounds from all directions you will want to go with the more common omnidirectional microphone. As the name suggests, a microphone that is called a cardioid or hypercardioid will pick up noise in a heart shaped form.

Another microphone that is aptly named is the shotgun microphone. As you may think, a shotgun microphone can pick up noise from a very precise location. Often referred to as radio mics, wireless microphones require an amplifier to transmit their electricity into sounds. You can learn more about the Saramonic Shotgun Mics here. If you think about it an intercom must function as both a microphone and a loudspeaker.

The most standard intercom can be used to both hear and speak to someone in a different room - think baby monitor or a desktop device allowing a parent to call their kids up for supper from the basement. Usually an intercom has handsets with a couple of simple buttons on them located in each room. The handsets can each function as both loudspeaker and microphone depending on which button is being pressed.

For years the military has utilized the basic intercom to allow people easy access to speak with one another. A person will simply push a button to talk and the microphone part of the device will be utilized, when the button is released the same device will work as a loudspeaker. The major problem with an intercom is the poor sound quality that is inherent when one device tries to serve opposite functions.

One of the benefits of using an intercom especially in public places is that they are much more difficult to break or vandalize. Often you will see an intercom instead of a regular telephone handset for use as an emergency device in elevators and in trains. Another important benefit is the ease of use.

The pressing of a single button transmits a person's voice and the simple release of the button turns the intercom into a loudspeaker so whatever the person on the other end has to say is easily heard.

To make it very simple to understand imagine a scenario in which a secretary is sitting in her office chair and needs to let her boss know that someone is waiting to see him.

As soon as the energy reaches into the loudspeaker it is converted back into sound waves. When he releases the button the process is reversed and the boss has a microphone that will change his voice into electric currents that travels through the copper wire back to his secretary still sitting in her office.

Although perhaps less scientifically interesting there are benefits to using an intercom without the hassle or tangle of wires or cables. Often, it is best to have both the loudspeaker and the intercom is its own handheld device.

Other intercoms may work similar to broadband over powerlines in which the sounds are sent through the wiring in the rest of the house instead of utilizing its own wiring. An example of another wireless intercom that may be operated using home power lines are baby monitors.

Often the parents unit will both transmit the noise and light up to alert the parents of any problems. This type of unit does not require any wiring between them. You can view the Saramonic Wireless lav mics ranges here. Well, you are in luck because It is possible to use a regular earbud and very easily create your own. All you really need to do is plug the earbud headphones into a microphone socket! This moves the coil, which causes current to flow as lines of flux from the magnet are cut.

So, instead of putting electrical energy into the coil as in a speaker you get energy out of it. In fact, many intercom systems use small speakers with lightweight cones as both a speaker and a microphone, by simply switching the same transducer from one end of the amplifier to the other!

Dynamic microphones are renowned for their ruggedness and reliability. They need no batteries or external power supplies. Output level is high enough to work directly into most microphone inputs with an excellent signal-to-noise ratio. They need little or no regular maintenance, and with reasonable care will maintain their performance for many years. Condenser or capacitor microphones use a lightweight membrane and a fixed plate that act as opposite sides of a capacitor.

Sound pressure against this thin polymer film causes it to move. This movement changes the capacitance of the circuit, creating a changing electrical output.

Condenser microphones are preferred for their very uniform frequency response, and ability to respond with clarity to transient sounds. The low mass of the diaphragm permits extended high-frequency response, while the nature of the design also ensures outstanding low-frequency pickup. The resulting sound is natural, clean and clear, with excellent transparency and detail.

Two basic types of condenser microphones are currently available. One uses an external power supply to provide the polarizing voltage needed for the capacitive circuit. These externally-polarized microphones are intended primarily for professional studio use or other extremely critical applications. A more recent development is the electret condenser microphone Fig. In these models, the polarizing voltage is impressed on either the diaphragm or the back plate during the manufacturing process, and this charge remains for the life of the microphone.

The best electret condenser microphones are capable of very high-quality performance, and are used extensively in broadcast, recording and sound reinforcement. Due in part to their low-mass diaphragms, condenser microphones are inherently lower in handling or mechanical noise than dynamic microphones.

For all of its electret condenser designs, Audio-Technica has elected to apply the polarizing voltage, or fixed-charge, to the back plate rather than the diaphragm. By doing this, a thinner material may be used for the diaphragm, providing a considerable performance advantage over electret microphones of conventional design. Condenser microphones have two other design advantages that make them the ideal or the only choice for many applications: they weigh much less than dynamic elements, and they can be much smaller.

The following pages will provide details. Some mics are designed for general use and can be used effectively in many different situations. Others are very specialised and are only really useful for their intended purpose. Characteristics to look for include directional properties, frequency response and impedance more on these later. The electrical current generated by a microphone is very small. Referred to as mic level , this signal is typically measured in millivolts. Before it can be used for anything serious the signal needs to be amplified, usually to line level typically 0.