In the structure of the Cannon(XLR) head, it has a metal or plastic shell with a tenon or hole for the tenon hook, so that the male and female heads will not fall off after joining; Its contacts can range from two to as many as seven, and most of the Canon(XLR) connections used in general audio equipment are three contacts. The Cannon head is different from the RCA head in that the RCA head must be a male head, and the seat must be a female seat (arrow point).

But Cannon joints are both male and female, both head and seat. In addition, the so-called head refers to the connection on the signal line can move the joint; The so-called male, that is, the signal contact is in the shape of a rod, similarly, the female is that the contact point is in the shape of a hole. In general, the output end of the signal is a male head or a male seat, and the input end is a female head or a female seat, in their own installation of a balanced expansion machine, or welding a balanced signal line can not be inadvertently, so as to avoid the dilemma of same-sex repulsion.

In the three contacts of XLR, the wiring is a certain rule; You can find that the three contacts on the plug or socket will be numbered 1,2,3, and number 1 must be the ground wire. The metal contact plate in hole 1 of the XLR female head or base is longer than that in hole 2 and hole 3. This is so that when connecting, the ground wire will finish the contact before the signal; When separating, the ground will be separated later than the signal, ensuring that there will be no accidental impact or damage to the horn when inserting and dialing the signal line in the startup state. Pins 2 and 3 are connected to the live wire and ground wire respectively.

One point must be noted in particular; The connection method of European regulations (including Japanese regulations) and American regulations system is the opposite, the second foot of American regulations is the fire line, and the third foot of European rules is the fire line. If you do not notice this, then after the different manufacturers of equipment, the sound of the whole system may be opposite in the end.

Therefore, it is best to look at the instructions before opening the sound, because every audio equipment with a balanced terminal will specify which foot is the fire line and which foot is the water line, as long as you carefully read the instructions to deduce; If you take all the way from the signal to the rear stage but find that the output is reversed, the easiest way is to invert the horn line.