【 Weak current College 】 mixer's basic operation principle

Sound mixer: Studio dedicated and dedicated two stage dance hall. 
Mixer's role is to:
1, pick up the signal, to zoom in;
2. press the required high, mid, bass tone Equalization;
3, will signal about bus as needed into or control group;
4, to feed into the secondary bus signal processing for art;
5. press the required output control. 
Mixer can be divided into input and output unit. 
(A) input cell input cell is an important component of a mixer, the input cell is tap parallel lines that are roughly the same per, generally can be divided into the following sections. 
A, input, select the portion of the TAPE: tape 1, 2, 3 MIC: microphone, LINE: line
B, the input Attenuator (PAD) if microphone or line input signal level is too high, while the gain control is unable to adjust, the attenuation switches to open when the preamplifier and input socket on the inserted a 20dB attenuator, to avoid overload. 
C, input gain control (GAIN) mixer sources are: microphones, musical instruments, tape, effects, sound amplifying equipment.
Because of their output level, in order to be able to match with them, we should use the mixer to gain control of the input sensitivity adjustment. If the input signal is too high can lead to clipping distortion, and vice versa if the input signal is too small, the noise will be unable to control the gain control is used to guarantee the sound mixer in fixed dynamic range. In the Panel gain control level size representation is 0dB = 775mV basis, depending on the size of the audio source output level, set in a different location. The input signal and gain level is shown in the following table. Gain (dB) 〓 input signals-60 to-50 〓 low-level microphone-microphone 35 〓 high (capacitance), electronic musical instruments-20 〓 low-level line (audio)
D, signal input jack is divided into low impedance balanced input (LO-Z card Lennon) and high-impedance unbalanced input (HI-Z 2 cores). General musical instruments and audio equipment in connection with non-balance, signal the "+" and "-" at one end and signal line screen public. For example: a core shielded cord, core wire is signal "+", shielded wire is signal and ground "-". This is better than no shielding of parallel lines induced noise, not belonging to the tube easy-masking. Professional audio device input and output are balanced, signal the "+" and "-" transport and then screened cables, "+" and "-" use independent of ground and plug XLR Plug me in using the card. 
E, overload (CLIP) overload is used to indicate the input signals instantaneous overload warning, the LEDs will peak (signal too large distortion level occurred) level when the glow below 3dB, easy to help set the gain switch location. 
F, input balance section input channel Equalizer is used on the input signal tone for the corrections to achieve a standard effect. As a result of a single control, so the mixer can make all the way to each balance control, but do not interfere with each other, the balance is divided into: HF (HIGH), medium (MID), LF (LOW). 0 location is flat; + direction (gain), + 15dB (enhanced 5 times);-direction (attenuation),-15dB (attenuation 5 times). Continuously tunable. Equalizer generally use the treble (10kHz), baritone (equalizer center frequency can move freely between 5kHz 350Hz — set), bass (100Hz) three equalizer. Because of the frequency section has a separate control, so you can enter a careful adjustment of the signal, which in turn can also adjust the tone for the bold attempt and squealing noise, noise, and so on not necessary ingredients to be effective.
1, high-frequency: 10kHz ± 15dB/slope impact zone: musical harmonics of the treble zone. Gain effect: metal sound increase, apical timbre comparison, gain too much noise can be clearly heard. Attenuation effect: can effectively remove hiss, attenuation is too much treble district of sense will be lost. 
2. intermediate: 3kHz ± 15dB/peak impact zone: musical instruments, voice and treble. Gain effect: the timbre brighter, harder texture, gain too much auditory fatigue susceptibility. Attenuation effect: music balance tends to bass, including sound will feel the same way. MF: 1kHz ± 15dB/peak impact zone: musical instruments, the human voice in tempo. Gain a clear effect: contour tone, sound phase forward sound projection, drum head modulated. Attenuation effect: after acoustic facies. MF: 500Hz ± 15dB/peak impact zone: the musical instrument, the bass voice. Gain powerful effect; timbre rich, gain too much telephone tone appears. Attenuation effect: tone head hard, balance tends too much treble, attenuation thin texture. 
3. low frequency: 100Hz ± 15dB/slope impact zone: musical bass area. Gain effect: a rich timbre, gain too much, the teeth tone is not clear. Attenuation effect: sound more relaxed sound good, tooth, background noise and loud hum noise effectively remove. 
G, acoustic phase knob for adjusting the crosstalk signal left, right balance, location in the channel after the level adjustment potentiometer. And each input channel signal on the Group 1-2 and 3-4 group rooms pan position location is determined by the knob. If the knob position in the Middle, pan position also in the middle. Knob to the left, navigate to the group in 1 or 3. Rotary tuning to discussions, positioned to the right in 2 or 4 groups. 
H, sniff (MON/SEND) sniff used to control the monitor bus input signal level value, this control in addition to gain control, is not subject to any control on the channel switch control (including the channel volume control). Therefore send signals and relatively independent of main bus bar signal. [fenye]
I, effects send (EFX/SEND) it includes all peripheral devices, used to determine the internal or external effect of the number of letters in theNumber into the input signal. It is balanced and volume attenuator, because each channel has its own effects sends, so by adjusting thenumber of channels, can make a difference, while other channels do not produce results. But be aware that internal and external effect one send control, so they should have the same audio source. 
J, listen switch (PFL/CUE) when this switch is "ON", the input channel signal to earphone to listen and to confirm the level meter, listens to switch on the order of precedence to firmly in mind.
Mixer operation terms and for the control of
GAIN: input signal HIGH-gain control: treble level control
MID-HIGH: treble level control LOW: bass level control
PAN: phase control MON.SEND: tap listens to signal control
EFX.SEND: tap effect signal control LIMIT (LED): signal amplitude indicator
LEFT.: left RIGHT signal level control: the right road signal level control
MONITOR: monitor system MON.OUT: monitor output
MASTER: General road level control EFX.MASTER: effect of the output level control
EFX.PAN: effect of phase control EFX.RET: effect return level control
Effect send EFX.MON: monitoring system level control DISPLAY: level meters
ECHO: reverb HIGHIIN: high-impedance input
LOWIIN: low resistance to enter OUT/IN: output/input jack
AUX.IN: auxiliary input multi-output MASTEROUT: total
EFX.OUT: effect of output results returned input EFX.RETURN:
LAMP: special lighting power supply POWER: total power switch
BALANCEOUTPUT: balanced output FUSE: a fuse
PEL: pre-listening (audition) press the EFF: effect of level control
MAIN: main LEVEL: channel balance control
HEADPHONE: Headphone Jack PHANTOMPOWER: phantom power switch
SIGNALPROCESSOR: signal processor EQUALIZER: equalizer
SUM: total output group switch LOWCUT: low frequency cut switch
HIGHCUT: high frequency switch PHONOINPUT resection: player input
STEREOOUT: stereo output ACTIVITY: dynamic indicator
CUE: selected to switch MONOOUT: mono output
PROGRAMBALANCE: primary output sound image control MONITORBALANCE: listen to output sound image controlr>EQIN (OUT): Equalizer access/exit key FTSW: foot switch
REV.CONTOUR: reverb profile regulates PA: fixed value decay, attenuator