Introduction: a unit of new multi-function hall acoustics acceptance standards, the field view, and sound control personnel exchanges and on-site audition, found a series of problems exist in the sound system, according to the analysis of the causes of the search, take corresponding measures, to achieve the desired effect, are provided for your reference.
First, the problems found in the audition and inspection
1. audition found problems:
First, system background noise is large;
The two is to be disturbed by the outside world, so that the sound system can hear the broadcast;
Three is the system ultra-low speakers, no sound;
The four mixer pre fader listening signal function can not be achieved;
Five is the effect of the device can not add effect.
2. site problems found in system configuration and installation:
First, the sound box installation is not adjusted according to the site and the use of the corresponding adjustment, resulting in microphone reinforcement is easy to whistle;
Two is the power amplifier installation is not standard. As the rack is not installed, and the amplifier is heavy, the front panel of the power amplifier distorts and distorts;
Three is the system equipment grade imbalance. For example, mixer, power amplifier and speakers are high-end imported products, and the effect of using equalizer, the lower grade of the unknown brand; four is the equalizer with the 3, the main output of the subwoofer output equilibrium, equilibrium, equilibrium of auxiliary output.
Two, cause analysis
1. audition found problems, causes analysis
The system background noise is large. We should pay attention to the identification of AC noise or electrical noise (rustling sound of water) interference. On a noise, the cause is poor, the majority of the audio signal cable disconnect connector, quality shield welding is not strong loose, not in strict accordance with the requirements of balanced transmission connection, there may be a bad grounding system grounding; then a noise is caused by the equipment. Because of the poor performance of the mixer, the power amplifier and the peripheral equipment and the low index, it often leads to a lower signal-to-noise ratio, which will lead to a larger electrical noise output.
The sound reinforcement system can hear the broadcast sound. The reason is that the signal line of the MIC input terminal of the mixer is not shielded properly, which leads the broadcast signal to be connected to the sound reinforcement system. Although the radio signal is very weak, which is also a radio frequency modulation signal, the general sound system is not possible to hear the broadcast signal, but the mixer is the input port of the microphone input, high sensitivity, such as the input signal line block (shielding layer floating) it will play the role of the antenna, a series circuit plus system equipment, play a role in the detection, hear the radio sound will be not at all surprising.
The system is super low speaker, no sound. In view of the signal flow of the system, the general super bass signal is taken out of the main channel signal or the grouping channel signal by the electronic frequency divider, and then is amplified to the subwoofer box by the corresponding power amplifier. From the above point of view, the key is to check the connection cables, connectors, and related equipment is normal.
The mixer pre fader listening signal function can not be achieved. Through field observation, this situation may be due to the fact that the operator is not familiar with the signal flow of the mixer, and does not place the button or monitor output button and the output knob in the correct position.
The system has no effect. As you know, there are many ways for effector access systems, but the most commonly used method is the so-called parallel method. This method is through the mixer AUX output to the effector input, the effect of the output returned to the mixer of a certain way into the LINE. This method will play a role in the normal, is through a road auxiliary output to the effect, to ensure the corresponding AUX channel knob a road input and output of the AUX will be opened, the corresponding knob also open, so the effect is to obtain the signal mixer one way, while ensuring that the effect of every pattern the knob and effect of correct control effect for input at the end of the tunnel will return the correct. These three links must be correct, the system can join the effect.
2. analysis of system configuration and installation
Sound box configuration position is unreasonable. The sound box should be placed flexibly according to the specific location, which is the main link to test personal experience and flexibility. The placement of the sound box not only affects the sound pressure distribution uniformity of the hall, but also affects the use effect of the system. Say more popular, that is, can guarantee that every place in the hall has the same sound, loudness and clarity, and not to open the volume of the microphone. But the hall form and different functions, the use of the myriads of changes is not consistent, installation and placement is not unified position, which bring confusion to many audio professionals, and most of us often feel confused. We should pay attention to, when placing speakers, to avoid the microphone can be facing speakers.
Power amplifier installation is not standard. Unless it is large, professional sound reinforcement system, power amplifier installation should be configured with a dedicated power amplifier room, using a dedicated power amplifier cabinet. In general, we always install the power amplifier and other system equipment in the same cabinet because of the limitation of the condition. Power amplifier installation requirements, must be placed on the shelf of the cabinet, and then fixed with a panel screw, such as multi-function hall, power amplifier installation is not standardized.
The system is out of balance. We are in the configuration of sound system equipment, we must first consider the equipment selection, a key principle is the grade of each equipment of the system should be basically the same, can not let the equipment level of disparity within the same system, or because of the barrel theory, high-end equipment can not play a good performance, become deaf ears. In the multi-function hall audio system, the high-end mixer, amplifier, speakers, equipped with low-end peripheral equipment, resulting in poor performance of the system, the effect is certainly poor.
