Mixing console, also known as the tuning console, amplifies, mixes, distributs, modifies the sound quality and processes the sound effects of multi-channel input signals. It is an important equipment for broadcasting and recording programs in modern radio broadcasting, stage amplification, audio program production and other systems.

Mixing table can be divided into: analog mixing table and digital mixing table.

Mixer type

There are differences in the number of input channels, the number of panel function keys and output instructions of the mixer. In fact, to master the use of the mixer, it is necessary to investigate it in general. Through practical operation and connection, it is natural to be familiar



Makes perfect. The mixer is divided into three parts: the input part, the bus part, the output part. The bus part connects the input part with the output part and constitutes the whole mixing table.

According to the purpose of use and use of different occasions, the mixer is divided into the following:

(1) Stereo Field Production Console

(2) Recording Console

(3) Music Console

(4) Digital Routing Mixing Console

(5) Powered Mixer with Power Amplifier

(6) Radio broadcast mixer (On Air Console)

(7) Theatre Console

(8) Audio mixer (P.A. Console)

(9) Wired Broadcast Mixer

(10) portable Mixer (Compact Mixer)

Mixing table action

(1) the socket and function key of the input part of the mixer

(1) Carnon socket MIC: this is the microphone socket, which has three jacks, respectively marked 1,2,3. Label 1 is ground (GND), connected to the machine housing, with the housing as 0 volt level. Label 2 is "HOT" or "HIGH" (HI), and it is one end of the signal that is transmitted. Labeling 3 is the Cold or Low end, which acts as the other end of the transmission signal. Since 2 and 3 have the same impedance relative to 1, and the impedance is low when viewed from the input, it is called a low-impedance balanced input jack. It has strong anti-interference and low noise, and is generally used for the connection of wired microphone.

Line input terminal: it is a 1/4" three-core socket, using 1/4" three-core plug (TRS), Tip, Ring and Sleeve, as the input of balance signal. A 1/4" two-core plug (TS) can also be used as a balance signal input. Its input impedance is high, generally used in addition to the microphone other sound source input jack.

3. Insert the socket (INS) : it is a kind of special use of outlet, through its internal, at ordinary times when you need to use, insert the 1/4 "three core plugs, line input or mic input sound signal from the Tip (Tip), treated with external devices, by Ring (Ring) again the sound signal to Return to the mixer, so the socket and he called out into the socket, some tune sticker into" Send/Return "or" in/out socket.

(4) fixed value attenuation (PAD) : press this key, the input sound signal (usually on the Line terminal input sound signal) will attenuate 20dB (that is, 10 times), some mixing station, its attenuation value is 30dB. It is suitable for large acoustic signal input.

⑤ Gain adjustment (GAIN) : it is used to adjust the input sound signal put a lot, it combined with PAD can make the input sound signal into the mixer in a high signal-to-noise ratio, small distortion of the best state, that is, can adjust the road peak indicator light in the best state to be bright.

⑥ Low cut button (100Hz) : Press this button, the frequency component of the input sound signal below 100Hz of the component can be removed. This button is used for sound amplification environment is not good, often low frequency buzzing and low frequency sound is not easy to absorb the sound amplification environment.

⑦ Equilibrium (EQ) : It is divided into three frequency bands: high frequency band (H.F.), middle frequency band (M.F.), low frequency band (L.F.), mainly used for sound quality compensation.

A. High frequency band (H.F.) : the tilt point frequency is 10kHz, and the lift and decline amount is? 15dB, this band mainly compensates for the clarity of sound.

B. Middle Frequency (M.F.) : Center frequency adjustable, range 250Hz? 8 KHZ; What is the lift and decline quantity of peak and valley points? 15 db. The range of the frequency band is very wide, and the compensation is around a central frequency. If the center frequency falls in the mid - to high-frequency band, the lift - down knob compensates the brightness of the sound. If the center frequency falls in the middle and low frequency band, the lifting knob compensates the intensity of the sound.

C. Low frequency band (L.F.) : the tilt point frequency is 150Hz, and the lift down amount is? 15dB, which is used to compensate for the fullness of the sound.

Was aided knob (AUX1 / AUX2 / AUX3 / AUX4) : adjust the knob, adjusting this voice to the size of the corresponding auxiliary bus which AUX1 and AUX2 acoustic signal from the pusher (Fader) lead before, not affected by the pusher. Aux3 and Aux4 sound signals are emitted from behind the Fader and are subject to large adjustment of the Fader. The former is labeled Pre and the latter is labeled Post.

⑨ Acoustic image adjustment (PAN) : it is used to adjust the spatial distribution image of the sound source. When to adjust to the left, equivalent to the road source on the left side of the listening sound. When adjust to the right, equivalent to the road source on the right side of the listening sound. If it is placed in the middle of the position, the equivalent of the road source in the middle of the listening sound. In fact, this knob is used to adjust the distribution of the sound source left and right knob, it is very important for the mixer to create stereo output.

Attenuating Attenuator (push Fader) : the function key plays two roles: on the one hand, it is used to adjust the proportion of the sound of the road in the mixing and mixing, pushing up the proportion is large, and pulling down the proportion is small; On the other hand, it is used to adjust the far and near distribution of the road sound source. Pushing up the sound is big, which is equivalent to putting the road sound source in a near position to make a sound. Pulling down the sound is small, which is equivalent to putting the road sound source in a far position to make a sound. Combined with the PAN, it can create the spatial surface distribution of each sound source. The mixer creates the stereo output using the Fader and PAN function keys.

The function keys

1. Monitoring button PFL (pre-fadelisten contraction) : for monitoring before attenuation, press it, and then the sound signal in front of the pusher can be heard by inserting the earphone into the headphone jack of the mixing station.

2. Switch On button ON: Press it, and the sound signal of the road is connected to the mixer for mixing.

3. L-R button: press it, the sound signal of the road is sent to the left and right sound channel bus after the push and PAN.

4. 1-2 Button: press it, the sound signal of the road will be sent to the marshalling bus 1 and 2 after the push and PAN.

5, 3-4 button: press it, the sound signal of the road is sent to the marshalling bus 3 and 4 after the push and PAN.

There are many kinds of mixers, but the main function keys are the same. It is worth mentioning that the mixer every way input can only enter a sound source, otherwise, will interfere with each other, impedance is not matched, the sound caused by distortion.

(2) mixer output part

Mixer output part of the arrangement has the following rules

(1) the mixer has several busbars, and there must be corresponding output sockets.

(2) each output socket output sound signal must be equipped with its corresponding adjustment key on the mixing table, may be a push and pull key, may also be a knob.

(3) There are monitoring keys next to each output adjustment function key. Generally, the monitoring button next to the push and pull key is the monitoring button before pushing PEL, and the monitoring button next to the knob is the monitoring button through the knob (AFL).

(4) The signal entering the mixing table from the jack of AUX RET or EffectrTN must be equipped with a button to adjust its size and the corresponding audio-visual adjusting knob PAN.

(5) In front of the sockets for output or editing output, there are generally corresponding INS (out and into the socket), the purpose of which is to separate the output signal before the output of special processing, but the auxiliary output is not installed INS jack.

(6) If the output part is equipped with a headset and an intercom microphone T.B.MIC jack, generally its bypass has its volume adjustment knob. If you master the above 6 rules, they will be on the mixer output part of the function of the key will be very well understood.

Key points of operation

(a) monophonic sound in Disco hall, dance hall or background music playback hall, often use monophonic sound, in these occasions do not need stereo sound. At this time, the mixer should be connected as follows:

(1) the use of auxSend auxSend, through the power amplifier (connected to the bridge), connected to the sound box, amplify. At this point, the amplified sound usually has no effect sound.

(2) the use of the left and right sound channel of one way output or group output of one way or mixed monophonic output, through the power amplifier (connected into bridge type), connected in series sound box for amplifying. In this case, the amplified sound usually has an effect sound.

(2) stereo sound amplification in OK hall, concert hall, karaoke room need to make stereo sound. Below this circumstance, use left and right sound channel output at the same time or use group output 1 and 2 or group output 3 and 4 send at the same time, classics work is put (connect stereo mode) with corresponding sound box to undertake amplify sound. At the same time, should pay attention to the placement of two sound boxes, as far as possible to expand the stereo field. In addition, attention should be paid to the spatial sound of each sound source, and the Fader and PAN on the road should be skillfully adjusted and their spatial positions should be properly arranged. For vocals and main instrumental notes, adjust the corresponding PAN in the middle position and push up the Fader to highlight vocals and main instrumental notes. If the input sound source is stereo, the original sound must be retained at the output end of the mixer, and the PAN and Fader on the road can not be placed arbitrarily, otherwise, the sound is chaotic, and even the singing sound and music sound can not be mixed together. The way to retain its original sound is to use the left channel input to occupy one road of the mixer and turn the PAN on the road to the left. The right channel input occupies the other way of the mixer and turn the PAN on the road to the right. At the same time, adjust the two pushers at the same height. In this way, the sound of the stereo source is preserved on the left and right channel busbars and the marshalling busbars.

(three) about monitoring usually refers to the stage monitoring, that is, for the stage performance personnel to listen to the sound, using the auxiliary mixer send (AUXSEND), sent to the monitoring power amplifier, stage monitoring sound box sound. For the sound that needs to be monitored, turn on the corresponding auxiliary knob on the road. For the sound that does not need to be monitored, the auxiliary knob of the corresponding road is closed, so you can supervise the sound of various music or singing alone. The earphone monitor is different from the stage monitor, the earphone monitor is used by the tuner to monitor the situation after the input of various sound sources and various mixed output conditions, with the help of this earphone monitor, you can check the sound source and correct the various adjustments of the mixer.

(4) the connection between the effect machine and the mixing table

1. INS jack, on the road in the use of each individual to effect on the way of acoustic signal processing, from INS jack will acoustic signal is introduced into effect of this machine, the effect of machine processing, sound effect by machine, and from this socket to the mixer, the connection is suitable for a large orchestra on the effect of processing of all kinds of music and singing voice.

2. AuxSend is used to send sound signals to the input end of the effect machine, and the output from the effect machine is connected to the AuxRTN end of the mixer. For the sound signals that need to be processed, the corresponding auxiliary knobs on the road will be turned on, and for the sound signals that do not need to be processed, the corresponding auxiliary knobs on the road will be turned off. This connection allows a single effect machine to handle multiple sources of the same kind (e.g., multiple people singing).

3. By means of an AuxSend, an audio signal is sent to the input of an effect machine from which the output Line is connected to a mixer. At this time, the road as the effect of reprocessing processing (amplification, balance, sound and image, mixing ratio, etc.), and use the road pushers for effect mixing ratio adjustment, more convenient. But all the auxiliary knobs on this road must be turned off. Otherwise, there will be amplification system howling, or effect sound on the auxiliary bus.

Aux Bus Auxiliary buses may be used as Effect buses, monitoring buses, wired voice control buses (to control lighting, etc.), or as separate recording and amplifying of certain sound sources. In short, the more auxiliary busbars, the more convenient the tuner to use, and even can do a variety of occasions with a mixer control synchronous sound or play a variety of different music.



Signal process

The flow chart is divided into three parts: the signal input part, the bus part and the signal output part. Sound source signal from the microphone input or input from the line, after gain adjustment, into the balance processing, for sound quality compensation, the use of attenuator (push) for mixing proportion adjustment. Then through the sound and image adjustment, into the left and right sound channel bus and the group bus, at the same time, before and after the push leads the sound signal, respectively into the auxiliary bus. Mixed sound signal from the bus, after mixing amplification, size adjustment, isolation, sent out the corresponding output of various. In addition, the sound signal sent from the auxiliary or the signal of external equipment, after the effect machine processing or other aspects of processing, from the auxiliary return end into the mixing table, make size adjustment and sound and image adjustment, and the signal on the left and right sound channel superposition, and then send out together, this is the whole process of sound signal.