[Amplifier audio] How to connect the power amplifier audio to the computer AV amplifier various interface connection methods
How to connect the power amplifier audio to the computer
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Speakers with amplifiers are called active speakers, and speakers without amplifiers are called speakers. The way to connect the active speaker to the computer is to use a connection with a 3.5 plug and a double lotus plug at one end, the 3.5 head is plugged into the headphone output of the computer, and the other double lotus head is inserted into the audio input of the active speaker. Turn on the power of the speaker, and adjust the volume knob of the speaker to control the volume. If the speaker without power amplifier cannot be directly connected to the output of the headphone, the volume will be very small, and an amplifier must be added.
Connection methods of various interfaces of AV power amplifier
“The three armies are not moved, the food and grass go first”, here we will talk about the connection with the power amplifier before talking about the connection of various interfaces and cables. Now is the era of digital transmission, so here only the digital transmission is mentioned, and the analog is not mentioned for the time being. Now the most popular is HDMI, in many new products, HDMI interface has become a standard configuration. HDMI is a new generation of multimedia interface standards. There are currently HDMI 1.0, HDMI 1.1, HDMI 1.2, HDMI 1.2a, HDMI 1.3 and other specifications. The HDMI interface in the new generation of AV amplifiers has become a must-have. Since the beginning of the HDMI 1.0 specification, the HDMI organization has defined support for DolbyDigital 5.1 (including Dolby DigitalEX) and DTS (including DTS-ES). While HDMI 1.1 added the function of supporting DVD-Audio, HDMI1.2 added the SACD function. HDMI 1.3 adds support for the new lossless digital surround audio formats Dolby True HD and DTS-HD Master Audio, so if you want to enjoy true next-generation audio, you must choose an amplifier and player with HDMI 1.3 specifications.
In addition, HDMI (except version 1.0) is capable of transmitting 8-channel 192kHz, 24-bit uncompressed audio, which is superior to all other consumer audio formats. Therefore, if the player can decode the audio format to multi-channel PCM, then it can transmit any of the above audio formats as a decoded PCM stream. In this way, many older A/V receivers that can support multi-channel PCM audio over the HDMI input can still be used to play the newer Dolby True HD and DTS-HD Master Audio formats.
Coaxial cable
Optical fiber In addition to HDMI, the transmission of digital audio signals mainly relies on two ways: digital coaxial cable with standard RCA interface Cable and SPDIF optical fiber transmission, both of which can better accomplish the goal of transmitting digital audio signals. Coaxial cables have a relatively complete shielding layer, and the copper core in the middle is the channel for signal transmission. Using 75 ohm coaxial cables to transmit digital audio signals is a very mature and high-quality way. This interface standard has low requirements on the hardware of the device, but when transmitting high-frequency signals, it is prone to relatively large attenuation, which affects the final sound quality. Compared with coaxial transmission, optical fiber has very strict requirements on the synchronization of equipment receiving and transmitting ends, which is technically more difficult to achieve than coaxial transmission. However, the advantages of optical fiber technology in long-distance transmission are very obvious, and there will be no coaxial cable. The problem of excessive long-distance attenuation is also favored by many users with distance restrictions and new decoration.
Connection between various HD players and next-generation power amplifiers
If you want to build a real theater of this generation, the power amplifier must support HDMI 1.3a standard , and supports decoding such as Dolby BTrueHD and DTS-HD MA. There are many real next-generation power amplifiers, such as Tianlong AVR-4308, AVC-3808, AVC-2808, AVC-2308, etc.; Onkyo TX-NA905, TX-SA875, TX-SA805, TX-SR803, TX-SA705, TX -SA606X, etc.; Marantz SR7002 and SR8002; Pioneer VSA-AX1AH, Sony TA-DA5300ES, Yamaha’s RX-V1800, RX-V3800, etc.
The real next-generation power amplifiers generally have multiple HDMI 1.3 ports. For example, TA-DA5300ES provides six HDMI 1.3 inputs and one HDMI1.3 output. The connection of the entire home theater is very convenient. For example, if you have all Blu-ray disc players, PS3, XBOX360, hard disk players, high-definition set-top boxes, and HTPCs, you can all connect to the six HDMI ports of the TA-DA5300ES power amplifier at one time. When choosing which player to use, you only need to select it, and the remaining HDMI output interface can be output to the TV. Of course, if your amplifier doesn’t have so many HDMI input ports, you can only connect less peripheral devices.
Blu-ray or HD DVD player connection to normal amplifier
If you have a Blu-ray player or HD DVD player, they must be HDMI interface (generally new products have HDMI 1.3, previous products may be 1.1 or 1.2), and they also have coaxial digital output and optical digital output interface, then it is the same as ordinary power amplifier (the ordinary power amplifier mentioned here). It is a non-HDMI 1.3 port, and does not support Dolby BTrueHD and DTS-HD MA and other decoding power amplifiers) There are three access methods, and these three methods are suitable for various high-definition players with HDMI interface at the same time, including high-definition hard disk playback device, high-definition set-top box, high-definition DV, etc.
(1) If your Blu-ray player or HD DVD player only has an HDMI output interface, and the power amplifier does not have an HDMI interface, only a coaxial or optical interface (general power amplifiers have both interface or one of them), then your connection method is to input the HDMI of the player into the TV through the HDMI interface (the situation mentioned here is that the TV has an HDMI interface. S video terminal input, the same as mentioned below, no special description), audio signal is input to the power amplifier through optical fiber or coaxial.
(2) If your Blu-ray player or HD DVD player only has one HDMI output interface, and the power amplifier also has two HDMI ports (the most basic configuration of the power amplifier with HDMI port is 1 HDMI input and 1 HDMI output), then your connection method is to insert the HDMI output interface of the player into the HDMI input interface of the amplifier through the HDMI cable, and the HDMI output interface of the amplifier is connected to the TV.
(3) If your Blu-ray player or HD DVD player has two or more HDMI output ports, and the power amplifier also has HDMI ports, then your connection method is to connect the player One of the two HDMI ports is input to the power amplifier, and the other is input to the TV. The method of point (2) can also be used.
How to connect the amplifier and audio?
Mixers, Equalizers, Compressors, Electronic Crossovers, Feedback Suppressors, Delays, Exciters, Digital Effects, Power Amplifiers, Speakers, Proper Connections.
One, the connection of the mixer
When it comes to the audio system, of course, we first think of the mixer, the mixer, there are many kinds of The most appropriate way to describe it is to compare the mixer to the heart of a sound system. How the blood circulates in the heart directly affects the performance of the entire system. Visually speaking, the mixer is like a large water treatment pool. We input various audio source signals into this large pool like flowing water, and then process the various water flowing in reasonably in the pool. Different channels flow out, the whole process is as simple as that. Therefore, the connection to the mixer is nothing more than two parts: input and output.
The line connection of the input part of the mixer:
The input signal of the mixer is generally divided into two types: low-impedance microphone signal input and high-impedance line signal input. In fact, we can regard the distinction between low resistance and high resistance as the difference in water pressure or water flow speed. For example, if the level of the high-resistance input is high, it seems that the water pressure is high and the water flow is fast. It is suitable to directly input it into the pool of the mixer. There is no need to add any links in the middle to adjust the water pressure and water flow rate; but The level of the low-resistance input is low, as if the water pressure is very low and the water flow is very slow. It is not suitable to directly input it into the pool of the mixer. Increase the pressure to make the water flow faster! Therefore, special circuit amplifiers are built into the low-impedance input channel lines of the mixer to amplify the low level to a suitable level. In this way, it should be well understood that the characteristics of water are used to describe low-impedance signals and high-impedance signals.
Only after distinguishing between high-resistance and low-resistance, you can select the correct wire for the corresponding connection. Generally speaking, the input jacks of the mixer can be basically divided into three types:
1. TRS: The high-impedance input part usually uses a 6.35cm TRS stereo connector as a balanced input, try not to use a 6.35 TS mono
(sound) connector as an unbalanced input, and now we use most of the audio source playback equipment such as: CD, The output signals of VCD, DVD, MD, MP3, etc. and most musical instruments are usually high impedance signals.
2. XLR: and low-impedance XLR connectors are usually used as balanced inputs. Now most wired microphones usually use low-impedance jacks to connect to the mixer.
3. RCA: If some mixers have TAPE recording input, it is usually connected by RCA lotus connector. Problems that need to be paid attention to in the signal input part of the mixer: It has been introduced that the input signal of the mixer can be roughly divided into low-impedance and high-impedance inputs, but how to accurately define whether a signal is low-impedance or high-impedance requires flexibility. For example, according to the standard, electronic organs, electric basses, electric guitars, etc. are high-impedance signals, which can only be input to the mixer with a 6.35 plug. However, in some places, the connection line from the stage to the mixer is too long, and the line resistance In addition to the system interference such as lighting, the background noise of this signal line is already very large. Even if no audio source signal is input, when the gain of the input channel of this line is turned up on the mixer, there will be noise. There is a lot of background noise, as described above: this line is a river, and now there is too much sediment in this river. At this time, there is a lot of noise in this line that cannot be changed, and the other side of the line is The volume of the instrument has been turned up to the maximum and can no longer be increased, that is, the river can only put so deep water for you, so what should I do? If you use a high-impedance signal input, it means that the water in the river does not increase, the water quality cannot be changed, and the sound quality of course cannot be changed; if you use a XLR plug to input a signal from a low-impedance jack, a little shallow water in the river will pass through the low-impedance amplifier. Amplification, so the depth of the water, the water quality is better, and the sound quality is also better. It doesn’t sound like it’s true, you can try it. In many projects I do now, the bands basically use XLR jacks for low-impedance input. Although it looks irregular on the surface, it is actually a helpless measure to reduce the noise of the band. So we still have to be flexible and find the best way to work in practice.
Line connections for the output section of the mixer:
The output section of professional mixers now has many sockets, and Each has its own division of labor, unlike the input part, although there are many sockets, it is relatively simple. Therefore, be careful when connecting the output signal. Usually the main output part of the mixer still refers to the total volume output, group volume output, AUX output, etc. Generally speaking, the output part of the mixer can be divided into 6 parts according to the function:
1. Group output: If we control the volume of the subwoofer by grouping 1-2, then the audio signal can only be output from the corresponding output jacks of the 1-2 grouping of the mixer. Most of the output ports of the grouping output use TRS stereo jacks for balanced output , of course, some use XLR sockets.
2. Main channel output: LR main channel usually adopts XLR XLR balanced output, and some small mixers also use TRS stereo jack instead.
3. AUX output: The AUX output in the mixer is most commonly used to output vocal effects devices, followed by monitoring signals for bands or singers, and of course it is also used for other purposes, such as : Recording, as an auxiliary speaker signal, etc. AUX usually uses TRS stereo jack output signal.
4. Direct output part: There is also a “Direct output” jack in each input channel of a professional mixer, which can be provided to other equipment for recording, monitoring, etc. Each channel of the mixer usually uses the TRS stereo jack output signal. For example, a performance TV station needs to be broadcast live, and the scene must also be broadcast live. If there are 20 channels of audio signals, then we can input these 20 channels of audio signals into the mixer of the TV station first, and then use the Direct output in the TV station’s mixer to directly output The jacks re-input the 20-channel audio source signals to the mixer for live performances. Of course, for the sake of safety, the 20-channel audio source signals are first adjusted and distributed through the signal amplifier distributor, and then sent to the TV station mixer, live performance mixer, backup emergency mixer, recording mixer or other. equipment, etc.
5. Recording output: Most of the general analog recording output signal jacks use RCA lotus connectors. If it is a digital signal, other digital output methods such as optical fiber and fire wire may be used.
6. INS insert and insert jack: This jack in the mixer is between the input and output, and it uses TRS stereo connectors to connect. About INS insertion and insertion, many sound engineers may not use it yet. It can insert a peripheral device into a certain input channel, group channel or main (left and right channel) channel of the mixer, and independently adjust the sound signal of the inserted channel. to be processed. When using, use the TRS big three-pin stereo connector to connect. The method is to output the signal from the head end of the TRS big three-pin stereo plug, connect it to the input end of the device to be inserted, and then send the signal from the output end of the device to the TRS big three-pin The loop end of the stereo plug, then flows into the mixer. For example, we can use this method to insert an equalizer into the 1 and 2 microphones of the mixer, which is equivalent to cutting off the water pipe of the 1 and 2 microphones, adding a water processor (equalizer), and then inputting to the Mixer, this way to adjust the sound effect is better. The above is the connection of the mixer. Whether it is the input part or the output part of the mixer, the sockets and signal connection methods used are basically these types, but pay attention to the correctness when connecting.
Second, the connection of the equalizer and the compressor:
1. Equalizer: As we all know, the main function of the equalizer is to adjust the tone, adjust the sound field and The sound feedback is suppressed, so the equalizer is almost an indispensable device in the current audio system. At present, the balanced input and output parts are all balanced jacks. When connecting, it is best to use balanced lines with XLR connectors. Of course, TRS can also be used. Connector for balanced lines.
2. Compressor: A compressor is a device that processes audio signals, which can compress or limit the dynamics of audio electrical signals. In fact, the main function of the compressor is to let it compress the high-level signal, so as to protect the lower-level audio equipment. It can be said that in a complete set of audio equipment, in addition to the mixer and equalizer, the compressor is the most important peripheral equipment. Therefore, under normal circumstances, the compressor should be placed in front of the power amplifier, and other peripheral equipment. Behind. Connections can be balanced lines with XLR connectors or balanced lines with TRS connectors.
Three, the connection of the electronic frequency divider:
The electronic frequency divider refers to the audio signal that can divide the 20Hz–20000Hz frequency band into suitable, Several different frequency bands are then sent to the corresponding power amplifiers, which are used to promote a kind of audio peripheral equipment of the corresponding speakers. The input part of the current electronic crossover is relatively simple, but the output part is more complicated: there are treble output, mid-range output, bass output and so on. When connecting, the output of the bass signal and the output of the high-pitched signal must not be confused, otherwise the high-pitched signal is given to the bass speaker, and the bass signal is given to the tweeter, so that there may be no sound in the audio system because the frequency is wrong. , Maybe it will burn out the speakers and other equipment! The electronic crossover can use balanced lines with XLR connectors or balanced lines with TRS connectors on the connection side.
Fourth, the connection of the feedback suppressor:
In terms of equipment connection, it also adopts the balanced line of XLR connector or the balanced line of TRS connector. The connection method is roughly It can be divided into the following three types:
1. The peripheral devices such as equalizers are serially connected in the audio system in sequence. The advantage of this connection is that the connection and operation are very simple, and it is suitable for simpler systems. . But the disadvantage is: when this connection method suppresses the acoustic feedback of the microphone, it will also affect other audio source signals passing through the feedback suppressor.
2. Use the INS insertion/insertion interface in the mixer channel to connect the feedback suppressor in series to the corresponding channel. Adjust without taking into account that it will affect other audio sources. The disadvantage is: with this connection method, a feedback suppressor can only control up to 2 channels of the mixer, and the utilization rate of the equipment is too low.
3. Use the INS insertion/insertion interface in the mixer group to connect the feedback suppressor to the corresponding group channel in series. The advantage is that the microphones programmed into this group can be processed. Centralized processing, and will not affect other audio sources. All in all, because this method can make full use of the feedback suppressor, it is also the most used connection method at present.
V. Connection of the delay device:
The delay device can delay the audio signal, and is generally used in some large sound field spaces, In systems that require multiple sets of speakers for distributed sound reinforcement. Because in such a system, after the sound is emitted by speakers at different positions, it will arrive at the listener’s ears in a sequential manner. Therefore, in order to ensure the consistency of the sound and image as much as possible, increase the readability of the sound, and avoid the turbidity of the sound. , flanger and trailing sound, we need to use the delay for related processing. Regarding the determination of the delay object, who is to delay? In fact, it is very simple, as long as you understand the following three points:
1. The first is people-oriented, no matter how many and good audio equipment is, it will serve people. Therefore, in a sound field, we must first Based on the audience.
2. The second is based on the main sound source, which is usually the location of the main speakers and the main stage. Ideally, the sound from the main sound source should be transmitted directly to the audience’s ears, which is the ideal state. However, due to the energy, range, directivity, and uniformity of the sound field sound pressure of the speakers, most of the indoor sound reinforcement systems now need to add some auxiliary speakers that are closer to the audience.
3. The third point mainly refers to the auxiliary fill speakers that are closer to the audience, that is, the speakers that may need delay processing. In most cases, the first factor is determined, the main sound source of the second factor is determined, and then the auxiliary fill speakers of the third factor are delayed. The speed of sound is about 340 meters per second, so the delay time is calculated based on the distance between the auxiliary speakers of the third factor and the main speakers of the first factor. When you know the delay object, you can connect the delay device correctly. The connection is basically like an equalizer and other peripheral equipment. It is connected in series in the signal channel that needs delay in the audio system. The balanced line of the XLR connector or the balanced line of the TRS connector is used. line to connect.
6. Connection of the exciter:
The audio exciter is actually a harmonic generator, which uses the psychoacoustic characteristics of people to improve the sound quality. Audio processing equipment for signal modification and beautification. The exciter generally has the following three connection methods:
1. It can be connected in series to the signal channel that needs to be excited in the audio system like peripheral devices such as equalizers, such as in a mixing console, 1. The -2 group is vocal. If you want to excite the vocals of this group, you can connect the exciter to the 1-2 group channel of the mixer using the insert/insert interface.
2. If you want to perform comprehensive processing, you can connect an exciter in series with the main volume output channel of the mixer or other output channels such as groups.
3. The exciter can also send out the signal from the AUX like the effector, and then return to the mixer, so that you can adjust which channels need to be stimulated, how strong the processing is, etc. This is actually more flexible. In terms of signal connection, the exciter also adopts the balanced line of the XLR connector or the balanced line of the TRS connector for connection.
Seven, the connection of digital effector:
The effector is an audio peripheral equipment that processes and produces various sound field effects. For processing, in most sound systems, if the vocal is not processed by the effect, it will become without fullness and brightness, that is: dry and without moisture. Now the latest effects use digital processing chips, so we also call them: digital effects. The effector is rarely connected in series in the audio system like the peripheral equipment such as the equalizer. Generally, the signal is sent from the AUX of the mixer to the input interface of the effector, and then the signal is returned from the output interface of the effector to the mixer. in the soundstage. In terms of signal connection, most of them are connected by balanced lines with TRS connectors, and some professional effectors also use balanced lines with XLR connectors for connection.
Eighth, the connection between the power amplifier and the speaker:
This should be familiar to everyone, just pay special attention: in terms of signal, the signal line of the power amplifier should be Try to balance the line as much as possible, this will minimize noise. Many sound engineers like to supply one or two signal lines to multiple power amplifiers, but if there are more than four power amplifiers, it is recommended to use signal amplifiers to separate enough signal lines without attenuation to supply each power amplifier for separate use. This can reduce system noise, reduce hidden dangers, and improve signal-to-noise ratio. In terms of power transmission, try to choose thicker and shorter speaker wires and use reasonable wiring to shorten the distance of the speaker wires, and then pay attention to the positive and negative electrodes to avoid short circuits.
Problems that need to be paid attention to when connecting the power amplifier equipment:
1. Pay attention to the power supply: the audio equipment must have a dedicated power supply, which must be separated from the lighting power supply, and Lights like lower voltages, but speakers require standard voltages. With a dedicated power supply, a stable and reliable power outlet is also required. You can try to use a “power sequencer”. Although the cost increases, it improves stability and ease of use. In conclusion: it is crucial to properly and securely connect the power to all audio equipment. Another point to note: some imported equipment will have 110V and 220V selector switches in the power supply. In my country, it must be confirmed that the 220V position can be connected and powered on.
2. Pay attention to the grounding of the equipment: It is very important to correctly connect the ground wire to all audio equipment. A good grounding can reduce the interference of equipment signal transmission and improve the stability of the equipment. It should be noted that the grounding wire should be made in accordance with the grounding standard of the lightning protection wire, that is, the conductor buried in the underground part should be rust-proof, well connected, and buried deep, and must not be shared with the grounding wire configured with the three-phase power line. Not only will it not reduce the noise in the sound system, but it can also easily damage the equipment.
3. Pay attention to choosing the appropriate signal line for connection: For an audio device, if we can connect with XLR balanced line, do not use TRS balanced line; if we can connect with TRS balanced line, do not Use TS mono unbalanced line to connect; when there is no way, you can use TS mono unbalanced line to connect equipment.
4. Pay attention to the inversion and short circuit of the signal: the short circuit of the signal line often causes silent failure, but it is very troublesome to check, unless the signal lines are removed and tested with a multimeter, so when welding the lines, Be especially careful.
5. Pay attention to the length of the signal line: When connecting the device, try to use a shorter signal line to save costs and reduce line resistance and interference. Under normal circumstances, the signal line using the balanced transmission method can be up to about 300 meters long, while the unbalanced line cannot be used for long-distance transmission.
6. Pay attention to the level of the device: if there is a +4 and -10 or -20 level switch on the rear panel of the device, we should put it in the +4 position under normal circumstances, which is the standard level.
7. Pay attention to the pass-through: many devices have a pass-through (Bypass) button, the device generally does not work when the pass-through is used, so we should pay attention to check this button, or if we let the compressor The straight-through does not work, and the equipment behind the compressor loses its protective function.
8. Be careful of misoperation: due to the many devices and buttons, misoperations are often prone to occur. For example, there is a “×10” button on some electronic frequency dividers. Be careful not to press it easily. down it. For example, if our crossover point is adjusted at 200Hz, pressing this button 200×10 will become 2000Hz, so we must avoid misoperation. With good equipment, coupled with the correct and reasonable connection them together, then the effect of this sound system will be perfect!
