Connecting method of mixer, equalizer, digital effect device, power amplifier and sound box

Mixer, equalizer, voltage limiter, electronic frequency divider, feedback suppressor, delay device, exciter, digital effect device, power amplifier, sound box and correct connection method.

First, the connection of the mixer

When it comes to sound system, of course, we will think of mixer first, and there will be many descriptions about mixer. The most appropriate method is to compare the mixer to the heart of the sound system. The blood circulation of this heart directly affects the performance of the whole system. Figuratively speaking, the mixer is like a large water treatment pool. We input all kinds of sound source signals into this big pool like running water, then treat the incoming water reasonably in the pool, and finally flow out from various channels. The whole process is as simple as that. So the connection with the mixer is nothing more than two parts: input and output.

(1) Line connection of the input part of the mixer:

The input signals of the mixer can be roughly divided into two types: low-resistance microphone signal input and high-resistance line signal input. In fact, we can regard the difference between low resistance and high resistance as the difference of water pressure or water flow speed. For example, the input level of high resistance is high, just as the water pressure is high and the water flow is urgent, so it is appropriate to directly input it into the pool of the mixer, and there is no need to add any link in the middle to adjust the water pressure and water flow speed; However, the level of low resistance input is low, just as the water pressure is very low and the water flow is very slow, so it is not appropriate to directly input it into the pool of the mixer. We need to add a water pump to the large pool, increase low resistance and low water pressure to speed up the water flow! Therefore, a special circuit amplifier is built in the low-resistance input channel line of the mixer to amplify the low level to an appropriate level. It should be well understood that the characteristics of water are used to describe low resistance signals and high resistance signals.

Only after distinguishing between high resistance and low resistance can the correct wire be selected for the corresponding connection. Generally speaking, the input sockets of the mixer can be basically divided into three types:

1, TRS: The high impedance input part usually uses the 6.35cm TRS stereo connector for balanced input, and the 6.35 TS single tone (sound) connector should not be used for unbalanced input. However, the output signals of most audio playback devices we use now, such as CD, VCD, DVD, MD, MP3 and most musical instruments, are usually high impedance signals.

2.XLR:XLR cannon connector is usually used as a balanced input with low resistance. At present, most wired microphones are usually connected to the mixer with low resistance sockets.

3.RCA: If there is a mixer with recording input, it is generally connected with RCA Lotus connector.

Problems needing attention in the signal input part of mixer: As mentioned above, the input signal of mixer can be roughly divided into low resistance input and high resistance input, but how to accurately define whether a signal belongs to low resistance or high resistance requires flexibility. For example, according to the standard, electronic organ, electric bass, electric guitar and so on. It is a high impedance signal and can only be input into the mixer with a 6.35 plug. But in some places, the connecting line from the stage to the mixer is too long and the line resistance is large. Coupled with the interference of lighting and other systems, the background noise of this signal line is already very large. Even if there is no sound source signal input, there will be a lot of background noise when the gain of this line input channel is increased on the mixer. As mentioned above, this line is a river, and now there is too much sediment in this river. At this time, a lot of noise on this line remains unchanged, and the volume of the instruments on the other side of the line has been adjusted to the maximum, which means you can only put so much water into the river. What should I do? If a high impedance signal is input, it means that the water in the river has not increased, the water quality can not be changed, and the sound quality can certainly not be changed; If the signal is input from a low-resistance socket with a gun plug, a little shallow water in the river will be amplified by a low-resistance amplifier, so that the water depth is deeper, the water quality is better and the sound quality is better. It doesn't seem true. You can try. Many projects I am doing now, the band basically uses cannon sockets to input from low resistance. Although it looks irregular on the surface, it is actually a helpless move to reduce the noise of the band. Therefore, we should be flexible and find the best working method in practice.

(2) Connection of mixer output circuit:

At present, there are many sockets in the output part of professional mixer, 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 parts of the mixer still refer to total volume output, grouped volume output and auxiliary output. Generally speaking, the output part of the mixer can be divided into six parts according to the function:

1. Grouped output: If we control the volume of the woofers individually by grouping the woofers into 1-2, then we can only output audio signals from the corresponding output jack of the mixer 1-2. Most of the output ports of grouped output use TRS stereo sockets for balanced output, and of course some use Cannon sockets.

2. Main channel output: The L-R main channel usually adopts XLR Cannon balanced output, and some small mixers are also replaced by TRS stereo jacks.

3. Auxiliary output: The auxiliary output in the mixer is most commonly used to output to the voice effect device, followed by providing monitoring signals for bands or singers. Of course, it also has other uses, such as recording, as an auxiliary speaker signal. AUX usually uses TRS stereo jack to output signals.

4. Direct output part: The professional mixer also has a "direct output" socket in each input channel, which can be provided to other devices for recording and monitoring. Each channel of the mixer usually uses TRS stereo socket to output signals. For example, if there are 20 audio signals, we can input them into the mixer of the TV station first, and then use the Direct output jack in the mixer of the TV station to input them into the mixer of the live performance. Now, of course, for the sake of safety, these 20 sound source signals are adjusted and distributed through the signal amplification distributor, and then sent to the TV station mixer, live performance mixer, standby emergency mixer, recording mixer or other equipment respectively.

5. Recording output: RCA Lotus connectors are mostly used for general analog recording output signal sockets. If it is a digital signal, other digital output modes such as optical fiber and firewire can be used.

6.INS plug-in socket: this socket in the mixer is connected between input and output through TRS stereo connector. Many sound engineers may not know how to insert ins. They can plug peripheral devices into the input channel, grouping channel or main channel (left channel and right channel) of the mixer, and independently process the sound signals of the inserted channels. When using, use TRS big three-core stereo connector to connect. The method is to output a signal from the head end of TRS big three-core stereo plug and connect it to the input end of the equipment to be inserted, and then send a signal from the output end of this equipment to the ring end of TRS big three-core stereo plug, and then flow into the mixer. For example, we can use this method to insert an equalizer into the microphones 1 and 2 of the mixer, which is equivalent to cutting off the water pipes of the microphones 1 and 2, adding a water processor (equalizer) and then inputting it into the mixer, so that the timbre adjustment 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 kinds, but attention should be paid to the correctness when connecting.

Second, the connection of equalizer and voltage limiter:

1. equalizer: As we all know, the main function of equalizer is to adjust timbre, sound field and suppress acoustic feedback. Therefore, the equalizer is almost an indispensable equipment in the current sound system. At present, the balanced input and output parts are all balanced sockets. It is best to use the balance circuit of XLR connector when connecting, and of course, the balance circuit of TRS connector can also be used.

2. Voltage limiter: A voltage limiter is a device that processes audio signals and can dynamically compress or limit audio electrical signals. In fact, the main function of the current voltage limiter is to compress high-level signals, thus protecting its subordinate audio equipment. It can be said that in a complete set of audio equipment, besides the mixer and equalizer, the voltage limiter is the most important peripheral equipment, so in general, the voltage limiter should be placed in front of the power amplifier and behind other peripheral equipment. The connection can be made using the balanced circuit of XLR connector or TRS connector.

Third, the connection of electronic frequency divider:

Electronic frequency divider refers to an audio peripheral device that can divide the audio signal in the frequency band of 20 Hz-20hz-20000Hz into appropriate different frequency bands, and then send it to the corresponding power amplifier to drive the corresponding speakers. At present, the input part of electronic frequency divider is relatively simple, but the output part is more complicated: there are treble output, midrange output, bass output and so on. When connecting, you must not confuse the output of the bass signal with the output of the treble signal, otherwise the treble signal will be given to the woofer and the bass signal will be given to the tweeter, so that the sound system may have no sound, because the frequency is wrong, and the speakers and other equipment may be burned out! The electronic frequency divider can use the balance circuit of XLR connector or the balance circuit of TRS connector on the connection surface.

Four, feedback suppressor connection:

In terms of equipment connection, it is also a balance line with XLR connector or a balance line with TRS connector. Connection methods can be roughly divided into the following three types:

1 is connected in series in the sound system, just like other peripheral devices such as equalizer. The advantage of this connection is that the connection and operation are very simple, and it is suitable for simpler systems. However, the disadvantage is that this connection mode will also affect other sound source signals passing through the feedback suppressor when suppressing microphone acoustic feedback.

2. Connect the feedback suppressors in the corresponding channels by using the INS plug-in/plug-in interface in the mixer channel. The advantage of this connection is that the feedback suppressor can be adjusted to the maximum extent regardless of the influence on other sound sources. The disadvantage is that this connection mode, a feedback suppressor can only control two channels of the mixer at most, and the equipment utilization rate is too low.

3. The feedback suppressor is connected in series in the corresponding grouping channel by using the INS plug-in interface in the mixer grouping. The advantage of this is that the microphones programmed into this grouping can be processed centrally without affecting other sound sources. Generally speaking, this method can make full use of feedback suppressor, so it is also the most widely used connection method at present.

Verb (abbreviation for verb) Connection of delay device:

The delay device can delay the audio signal, which is generally used in some systems with large sound field space and need multiple groups of speakers to disperse the sound reinforcement. Because in such a system, after the sound is emitted by speakers in different positions, it reaches the listener's ears in sequence, so in order to ensure the consistency of the sound image, increase the readability of the sound, and avoid the turbidity, ringing and tailing of the sound, it is necessary to use a delay device for related processing. Who is delaying the determination of the object? It's actually quite simple. As long as the following three points are clear:

1, the first is people-oriented, no matter how many best audio equipment there are, the audience should be the benchmark in a sound field first.

2. The second is based on the main sound source, usually the position of the main speaker and the main stage. Ideally, the sound emitted by the main sound source should directly reach the audience's ears, which is the most ideal state. However, due to the speaker's energy, range, directivity and sound pressure uniformity, most of the current indoor sound reinforcement systems need to add some auxiliary speakers closer to the audience.

3. The third point mainly refers to these auxiliary speakers close to the audience, that is, speakers that may need delay.

In most cases, the first factor is determined, the main sound source of the second factor is determined, and then the sub-speaker of the third factor is delayed. The speed of sound is about 340 meters per second, so the delay time is calculated according to the distance between the auxiliary speaker of the third factor and the main speaker of the first factor. Only by knowing the delay object can the delay device be connected correctly. Basically, this connection is connected in series in the signal channel that needs to be delayed in the sound system like equalizer and other peripheral devices, and is connected by using the balance circuit of XLR connector or TRS connector.

Six, exciter connection:

Audio exciter is actually a kind of harmonic generator, which uses the psychoacoustic characteristics of human beings to modify and beautify the sound signal. Generally, the exciter has the following three connection modes:

1 can be connected in series in the signal channel that needs to be excited in the sound system like an equalizer and other peripheral devices. For example, a mixer, 1-2 group is human voice. If you want to excite this group of vocals, you can connect the exciter to the 1-2 channel of the mixer with the plug-in/plug-out interface.

2. If comprehensive processing is needed, it is enough to connect an exciter in series with the main volume output channel of the mixer or other output channels such as grouping.

3. The exciter can also send a signal from AUX like an effector, and then return it to the mixer, so that you can adjust which channels need to be excited and how hard it needs to be processed, which is actually more flexible.

In terms of signal connection, the exciter is also connected through the balanced circuit of XLR connector or TRS connector.

Seven, digital effect device connection:

Effector is an audio peripheral device that processes and creates various sound field effects, and is generally used to process human voices. In most audio systems, if the human voice is not processed by the effector, it will become less plump and bright, that is, dry and without moisture. Now the latest effectors are all digital processing chips, so we also call them: digital effectors. Effectors are rarely connected in series in a sound system like equalizers and other peripherals. Generally speaking, they send the signal from the AUX of the mixer to the input interface of the effector, and then return the signal from the output interface of the effector to the mixer. In terms of signal connection, most of them use the balanced circuit of TRS connector, and a few professional effectors also use the balanced circuit of XLR connector.

Eight, power amplifier and speaker connection:

Everyone should be familiar with this, but we should pay special attention to it: in terms of signal, the signal lines of the power amplifier should be balanced as much as possible to minimize noise. Many sound engineers like to provide one or two signal lines for multiple power amplifiers. However, if there are more than four power amplifiers, it is suggested to use signal amplifiers to divide enough signal lines without attenuation for each power amplifier, which can reduce system noise, reduce hidden dangers and improve signal-to-noise ratio. In terms of power transmission, try to use thick and short speaker wires, adopt reasonable wiring, shorten the distance of speaker wires, pay attention to positive and negative poles and avoid short circuit.

Problems needing attention in equipment connection:

1, pay attention to power supply: audio equipment should have a dedicated power supply, which should be separated from the power supply of lighting. Lighting likes lower voltage, but audio needs standard voltage. With a dedicated power supply, there must be a stable and reliable power socket, and try to use the "power sequencer". Although the cost has increased, the stability and ease of use have improved. In short: it is very important to connect the power supply of all audio equipment correctly and firmly. One more thing to note: some imported equipment will have 1 10V and 220V selector switches in the power supply section. In China, you need to confirm that the 220V position is selected before you can connect and power on.

2. Pay attention to the grounding of the equipment: It is very important to connect the grounding wire correctly to all audio equipment. Good grounding can reduce the interference of equipment signal transmission and improve the stability of equipment. It should be noted that the grounding wire should be made according to the grounding standard of lightning protection wire, that is, the conductor buried underground should be rust-proof, have good contact and be buried deeply, and must not be used together with the grounding wire equipped with three-phase power line, which will not only reduce the noise in the audio system, but also easily damage the equipment.

3. Pay attention to selecting the appropriate connection signal line: an audio device, we can connect it with XLR cannon balance line instead of TRS balance line; If you can connect TRS balanced line, don't connect TS mono unbalanced line; Only when there is really no way can the TS mono unbalanced line be used to connect the equipment.

4. Pay attention to signal phase inversion and short circuit: short circuit of signal line often causes silent fault, but it is very troublesome to check, unless the signal line is removed and tested by multimeter, so be especially careful when bonding wires.

5. Pay attention to the length of signal wire: when connecting equipment, try to use a shorter signal wire to save costs and reduce line resistance and interference. In general, the longest signal line of balanced transmission mode can reach about 300 meters, while unbalanced line cannot be used for long-distance transmission.

6. Pay attention to the level of the equipment: If there are +4 and-10 or -20 level switches on the back panel of the equipment, we usually put them in the position of +4, which is the standard level.

7. Pay attention to direct connection: Many devices have a direct connection button, which generally doesn't work, so we should pay attention to checking this button, otherwise, if we let the voltage limiter pass through, the equipment behind the voltage limiter will lose its protection function.

8. Beware of misoperation: Because there are many devices and buttons, misoperation often occurs. For example, some electronic frequency dividers have a "× 10" button, so please be careful not to press it easily. For example, if our intersection is adjusted to 200Hz, pressing this button 200 × 10 will change it to 2000Hz, so we must avoid misoperation.

With good equipment and correct and reasonable connection, the effect of this sound system will be perfect!