The XLR or Cannon is a type of connector that usually connect balanced lines. In fact, it is more balanced connector used for professional audio applications, and is also the standard connector used in entertainment lighting equipment to transmit the digital control signal "DMX". His nickname cannon, for which he is best known in Spain is that the first to be used in this country, were made by theITT/CANNON brand, and carried "cannon" stamped on the chassis. It has three pin plug and European standard for audio signals is as follows: for the earth or mesh. for one-phase signal, known as a living or hot to the back or push-pull signal, known as return or cold. It is available in version 3-pin and 5-pin.

One hertz is one cycle per second, meaning repeating cycle as an event. For example, hertz is applied physics measuring the number of times for a second wave (either acoustic or electromagnetic) is repeated or can be applied, among other uses, to ocean waves that reach the Beach vibrations per second or a solid. The quantity that measures the frequency hertz is called,in this regard, the inverse of the period. One hertz is an oscillation frequency of suffering a particle over a period of one second.

We can find 3 types of jack connector, monaural TS connector (tip-sleeve), TRS (tip-ring-sleeve) and TRRS stereo plug (tip-ring-ring-sleeve) which is used in most mobile devices, tablets, MP3 etc ...
We can difference these 3 types of connectors according to their diameter:

1. 6.35 mm jack connector or TS.
2. 3.5mm minijack connector or TRS, is the most common, usually used in headphone's output of portable devices.
3. 2.5mm jack connector or TRRS.

It consists of a maximum of three connecting parts being called the largest mass or negative polarity and two smaller size located more towards the end of the connector,
The called positive that correspond to each channel, such three-part plug can transmit signals in two separate channels, also known as stereo signals. There's a mono version, consisting of only two parts, a negative and a positive.

A. Protector
B. Stem
C. Ring
D. Tip
E. Kindred
F. Ring (Signal Right)
G. Tip (Signal Left)

for fine adjustments, in very small capacitance ranges.