All of the electronic circuit,
Also include internal mixer circuit,)
A low level of electronic noise (
Or call hiss, hum)
, although you can use careful design will take her to the lowest, but absolutely can't completely disappear (
, the input signal level too, however, can make the sound system circuit to produce distortion, so set the input level must be very cautious, to get the best sound quality (
The sound quality)
, of course, ideal is the input level, the higher the better,
Input level is high, the signal-to-noise ratio is high)
, but we must keep a safe space to avoid the highest level of distortion, this not only ensure the signal level is big enough to drown and ignore the background noise and you can also keep the signal clear under avoid distortion.
The safety space in sound professional terminology is called 'allowable range' (
Good design is to use a very low noise circuit, but still provides a lot of allowable space, in order to avoid some unpredictable signal peak clipping distortion caused by peak, PA live performances, the mixer is sufficient to allow space is very important in the practical application, because the size of the signal level is unpredictable, part of easy to produce peak clipping mixer, increase the risk of damage to the high frequency drive.
The design of the electric meter is the best signal level zero vu, such an arrangement can leave a lot of spare space to deal with the unpredictable signal peak, to monitor the real peak signal level, please use the peak meter display type, rather than look at the shape of the average display meter.
Set the input gain program: 1, press to adjust the channel PFL (persistent functional language) key and through headphones listening in.
2, adjust the input gain control knob to no surge signal's voice, for example, the top right of the LED indicator (volume
Will be displayed in the about '0' position, if it is a small drum, is increased to about + 8 position, the program must be set in each channel to repeat, to other work.
If the gain setting is too high, the margin was reduced, the possibility of peak distortion relative increase, on the contrary if the input gain is too small, we will have to compensate in other parts of mixer, the end result may be out of a lot of unnecessary noise (
Please note: the effect of the signal size must also be adjusted in the best condition, aux output control knob to turn about 3/4, then adjust the input gain in fx, make the signal peak at about the position of the electric meter 0 vu effect instrument itself, any effect instrument at the insertion point, must have to use their own input gain control, the gain is transferred to the best, if you have any input level control effectors, should also be in the first set to 3/4 place.
Airport in the input channel processor or main output channel when the insertion point, if they can be set at + 4 bu (
Work can not need to modify and directly play the best effect, because all of the insertion point at 0 is a high level of work.
The good habit of gain adjustment precision should be engineer, also should be a routine, we spend some time and thought carefully set, must be able to reach PA equipment hundred of potential.
Assume that sound system in the mixer output main push rod 0 db, the distance of 10 meters measured sound pressure is 85 decibels, if need to adjust the volume, under the condition of the electric meter did not reach peak distortion, push the push rod to + 5 db location, we can learn that the same location of the sound pressure has become 90 decibels, push rod to the?
5 db location, it can be there about 80 decibels of sound pressure have been measured, there is the result of the relatively, can we know what we move the push rod has changed!