[Home Theater Network HDAV.com.cn] There are many kinds of connections for home theater audio systems, and different systems and devices have different connection methods. But in general, the principle is the same, mainly: audio source + amplifier + speaker.
1. The current sound source includes various instruments, various sound source players and some special sound generators.
2. The power amplifier is composed of various amplifying circuits, which can amplify the signal of the previous stage to promote the speaker of the latter stage.
3, now generally combine multiple speakers together to form a speaker, also composed of many types of speakers.
The above is the simplest home theater audio system. Of course, many auxiliary devices have been added to the current system, which we call: peripheral devices. I generally use the home theater audio system flexibly according to the characteristics of use and the requirements of the customer. However, the home theater sound effects produced by different connection methods of the same equipment are different, so technicians are required to master this knowledge. .
Common cables and connectors in home theater audio systems
In the home theater audio system, the communication and communication between the equipment and the equipment must be based on the tools connected to it. This is the wire and the connector. It occupies a very important role in the entire home theater audio system. Now there are many types of connectors and connectors used in professional home theater audio systems. Here we briefly introduce the common types of wires and connectors:
First, all kinds of wire
1, professional audio cable
Now the audio cable has two cores, three cores, four cores, five cores, etc. This kind of line can be used to transmit high quality audio signals because of the good shielding effect; now more professional microphones generally use more than three cores. The wire has strong anti-interference ability and can be transmitted over long distances. Of course, this wire can also transmit other signals, such as DMX512 control signals for transmitting computer lights.
2, coaxial cable
Generally used in video, there are also some audio cables. Because of the poor anti-interference ability of this cable, and the design is not mainly used to transmit audio signals, it is not suitable for long-distance audio signal transmission.
3, centralized cable
That is, multiple signal lines are wrapped in the same protection tube, which is generally used inside the connection system to reduce the number of independent wires. It is now also used in special vehicles such as TV OB vans, underground pre-buried and other. This kind of line is generally processed by professional manufacturers, and the quality is more secure.
4, fiber
Many transmission cables commonly used on recording equipment such as CDs or MDs transmit digital signals. With the popularity of digitalization, the use of optical fiber in home theater audio systems will increase in the future.
5, MIDI line
Usually a five-core cable that carries information about MIDI, and most of it is now used on keyboards, effects, and more.
6, there are some special wires
For example, the multi-core cable used to connect to the network in the computer karaoke system can now also be used to transmit audio and video, and realize the automatic on-demand function of the computer.
Second, various connectors
1, XLR
Commonly known as the cannon connector (Cannon), this connector is composed of three contacts, respectively 1 - Ground ground; 2 - hot end (+ level); 3 - cold end (- level), of course, some equipment provisions 3 is the hot end (+ level); 2 is the cold end (-level), this point to see the device's instructions.
The cassette connection plug-in is the most widely used type of connector in professional home theater audio systems. It can be used to transmit various audio signals in home theater audio systems. Generally, balanced input and output terminals are connected by card connectors. of. In a sense, the use of card connectors is also one of the characteristics of professional home theater audio systems that are different from civilian audio. The benefits are:
a. Using balanced transmission mode, it has strong resistance to external interference, which is conducive to long-distance transmission.
b. With spring locking device, the connection is reliable and it is not easy to pull off.
c. The connector specifies the signal flow direction to prevent errors on the connection.
The plug has a male plug and a female plug, and the socket also has a male socket and a female socket. The male plug is the pin, and the female plug is the jack. According to the common practice in the world, the input terminal is used as a signal with a male plug or socket; the female plug and socket are used as the output end of the signal.
2, RCA
In China, it is commonly known as the lotus head (seeing the lotus petal for some types of RCA joints). The joint is composed of two joints, which are hot end (+ grade) and cold end ground (grade). Use coaxial cable connection, of course, you can also use multi-core audio cable, often used in general home theater audio equipment. Because it is about 3.5 cm in length, I usually call it: 3.5cm plug.
3, TRS
Generally called stereo connector, it is composed of three contacts, namely: head end (+ level); ring end (-level); ground (Ground), used on small headphones, the length is about 3.5 cm, but most It is still used in professional home theater audio, its length is 6.35 cm. At present, the high-impedance input and plug-in jacks of professional mixers mostly use this plug. Most other home theater audio equipments also use this port.
4, TS
Commonly known as a single (sound) connector, this connector is composed of two contacts, the head end (+ level); ground (Ground). The above two connectors, used in professional home theater audio, have a length of 6.35 cm, so I usually call it: 6.35 cm plug. Although the TS connector and the TRS connector are the same length and similar in appearance, the specific functions can be different. The TRS stereo connector can transmit signals in a balanced manner with a three-core cable; however, the TS mono connector can only use unbalanced signaling. the way.
5, MIDI connector
Using a connector on a MIDI application, there are five pins that carry information about MIDI.
6, speaker connector
Four-core professional connectors are now commonly used, and some use TS mono connectors or other methods.
7, all kinds of adapters
This connector can be easily used to switch between various joints.
8. There are other special connectors that are not introduced here.
Third, the production of connecting lines in the home theater audio system
At present, the input and output signal modes of professional home theater audio equipment are basically divided into: Balance balance mode and Unbalance unbalance mode. Of course, the balanced and balanced, unbalanced and unbalanced ports can be directly fed with signals; in the case of higher requirements, between the balanced and unbalanced ports, special converters must be connected to each other. However, in actual engineering, as long as the signal line is not too long and the interference is not too large, the balanced port and the unbalanced port can be directly connected to the normal transmission signal. In a home theater audio system, in addition to the power transmission line between the amplifier and the speaker, the signal connection between other devices should be transmitted in a balanced manner as much as possible, which can improve the anti-interference ability of the system and increase the signal. Effective transmission distance:
A. Signal line between balance and balance:
1, XLR card 侬 male connector → XLR card 侬 female connector
This kind of line is used most in the professional home theater audio system. In the production aspect, the three contacts of the card, the male and the female are connected, the contact 1 is connected to the shielding layer, and the contact 2 is connected to the signal hot end (+ Pole), contact 3 is connected to the cold end of the signal (-pole).
2, TRS stereo connector → TRS stereo connector
In the production aspect, the three ends of the two TRS stereo connectors (+ level), the ring end (-level), and the ground (Ground) are respectively connected. This kind of line should actually be used in a large number in home theater audio systems, but many sound engineers often use TS monophonic (sound) connectors instead because of the troubles. This is especially important to note that this alternative signal transmission method Balanced transmission becomes unbalanced transmission.
3, XLR card male or female connector → TRS stereo connector
The contact point 1 (shielded ground) of the XLR侬 connector of the card is docked to the ground of the TRS stereo (Ground); the hot end (+ pole) of the XLR contact 2 is connected to the head end of the TRS (+ pole); the XLR contact 3 is the cold end (-pole) Dock the ring end (-pole) of the TRS. This is also a balanced transmission method that is often used in professional home theater audio systems.
4, XLR card → public → XLR card 侬 public or XLR card → mother → XLR card 侬 mother
This kind of line is a bit special, it is used up to the signal connection between the power amplifier and the power amplifier or between the power amplifier and other peripheral devices. In the production aspect, the three contacts of the two connectors are connected, and the contacts are connected. Shield, contact 2 is connected to the hot end of the signal (+ pole), and contact 3 is connected to the cold end of the signal (-pole).
Another point, in order to prevent "loop interference", we can vacate one of the XLR card joints of one of the signal lines (shield ground) or the ground of a TRS stereo connector (Ground) in a special case. Not connected, for example: an XLR card 侬 public to the XLR card 侬 mother's balance line, we can vacate the XLR card 侬 female connector inside the contact 1 (shield ground) to not connect, so as to avoid some interference between the devices; The principle of the TRS connector is the same, just vacate a ground contact. Such a balance line we originally had to weld 6 solder joints at the time of production, and now one is to weld 5 solder joints, but the unbalanced line cannot use this method.
B. Signal line between unbalanced and unbalanced
Generally refers to the signal line between the TS single tone (sound) connector and the TS tone (sound) connector. This is an unbalanced transmission method. The head between the two TS monophonic (sound) connectors is separately produced. The two ends of the end (+ level) and the ground (Ground) are respectively connected.
C, the signal line between balance and non-equilibrium
XLR card or XLR card connector → TS single tone (sound) connector, this connection mode has actually become an unbalanced transmission mode, and the joints 1 and 3 of the XLR card connector are combined and shielded. The line then docks the ground of the TS tone (sound) connector; the XLR contact 2 hot (+ pole) docks the head (+ pole) of the TS tone (sound) connector. In professional home theater audio systems, such lines are often used in the box karaoke system for microphone lines.
D, speaker cable
In the professional home theater audio system amplifier and speaker connection, the speaker line resistance should be as low as possible, choose thick, short wire and reasonable wiring. Today's speakers generally use four-core professional connectors, and the power amplifiers also generally use four-core professional connectors or binding posts. In terms of production, the speaker's four-core professional 1 (+ pole) and 1 (-pole) and amplifier output ( +Pole and (-pole) are properly connected. There are also speakers or amplifiers that use TS mono connectors and binding posts, which are connected in the same way. All are positive to positive, negative to negative, if reversed, the speaker will reverse, which will affect the sound quality and stability of the speaker, while avoiding short circuit when connecting, otherwise it will damage the power amplifier equipment.
In general, the above is the type of cable we often use in the system. Maybe we didn't pay much attention to the connection of the signal cable and the speaker cable. Take the signal cable as an example: in fact, it is just as important as the blood vessels in the human body! From the perspective of stability and long-term, we must use high-quality wire and high-quality plugs, and ensure that they are welded with high quality and trouble-free. Now, when I do the project, no matter how busy and tired, I am used to soldering all the signal cables in the system. If the signal line connected by others is connected to the system, there is no point at all, just like you don’t know how to move forward. There will be a mine on the road. You don't know which signal line will fail. So, relatively, the bad equipment can also believe its stability, but I don't believe in quality. Not guaranteed signal cable and speaker cable!
Fourth, home theater audio system equipment connection order
After making all kinds of signal cables, we have to prepare for the device connection. Now there are more peripheral devices in the home theater audio system. There must always be a connection in the connection. I have already introduced it in a series of articles last year. Here are a few simple join sequences:
1. Bass system equipment connection sequence: mixer (1-2 groups) → equalizer → crossover → compressor → bass amplifier → subwoofer.
2, auxiliary home theater audio system equipment connection sequence: mixer (3-4 group) → equalizer → delay device (optional) → pressure limiter → auxiliary speaker amplifier → auxiliary speaker.
3, the main audio system equipment connection sequence: mixer (LR main channel) → equalizer → exciter (optional) → feedback suppressor (optional) → pressure limiter → main speaker amplifier → main speaker.
4, monitoring system equipment connection sequence: mixer (AUX output) → equalizer → pressure limiter → monitor speaker amplifier → monitor speakers.
The first connection method above can control the volume of the bass separately, so that the volume of the mixer 1-2 group can be increased when it is slow or dip, and it can be opened when the singer sings, which is very flexible. The second connection method can also control the sound of the auxiliary speaker very well; the third main speaker we are used to output the volume from the LR total output of the mixer; the fourth kind of monitoring system, the standard is from AUX The volume is output so that the volume of each channel of the mixer can be flexibly adjusted according to the requirements of the singer or band, but in a smaller home theater audio system, the monitor signal can be taken directly from the main channel signal. The above 1st and 2nd connection methods should also pay attention: since 1-2, 3-4 groups, we have independently output signals to the bass system and auxiliary system from the corresponding output ports, then 1-2, 3- 4 groupings should not be output through the total volume of the mixer, that is, the switch of 1-2, 3-4 grouping to the total volume of the mixer should not be opened.
Of course, we still have to flexibly arrange the order of the devices when they are needed according to the number of devices and the number of devices. The above order is for reference only.
Fifth, the main points when the equipment is connected
The above briefly introduces the types of various connection lines, the production and the connection order of the devices. In the specific connection of the devices, facing a wide variety of device sockets, many sound engineers do not know how to start, but it is very simple. Everyone just needs to remember the following points:
1, Balance balance mode
Nowadays, the sockets on the rear panel of most home theater audio equipment are balanced ports. We just choose to connect the equipment with the balanced line of the XLR card connector or the balanced line of the TRS 6.35cm stereo connector.
2, Unbalance unbalanced party
Although most of the sockets on the rear panel of home theater audio equipment are balanced ports, some devices still have unbalanced ports. For example, some electronic crossover output jacks are marked with: Balance OUT (balanced output) And Unbalance OUT (unbalanced) output, so we can also use the unbalanced line of the TS 6.35cm mono connector to connect the device, as long as the line is not too long, the interference is not too large, so the connection is still possible.
3, IN input and OUT output
Some beginners look at the back of the device with so many sockets that they are dizzy. In fact, there is a flaw: no matter what home theater audio equipment, basically can be divided into two parts of "IN input" and "OUT output", so we Just look for "IN and OUT", and don't connect any other unfamiliar sockets. In short, the connected equipment is like running water: the upstream water will flow into the "IN input"; the water flowing downstream will pass. OUT output "flows out again, so the first level is not very simple? More fresh and fun home theater information, please pay attention to home theater network http:// (WeChat: cnhifi), The nation's most influential home theater audio player interactive media site.
Note: This article is transferred from Solan. The article is an independent view of the author and does not represent the position of the home theater network.
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