Assist outdoor performances, sound technology needs to pay attention to these.

For indoor performances such as theater stages, the primary requirement is sound artistry; first and foremost, it is essential to ensure high-quality, pleasant and beautiful timbre. For outdoor artistic performances, however, the top priority is sound technology, with the primary goal of guaranteeing a smooth, accident-free performance. Therefore, outdoor open-air performances are more difficult than indoor ones and have many specific technical requirements.

01 Sufficient Power Reserve for the Audio System
　　An open-air outdoor sound field requires powerful power. Because to increase the sound pressure level by 3dB in an outdoor sound field, the power needs to be increased by 10 times. According to the sound pressure level formula dBspl=20log(p1/po)=20log(L1/L2)=10lg(P1/P2), we can derive 10logp2/p1 =xdb, which can be used to calculate the specific values of the sound field.
　　
02 Selection of High-Sensitivity Microphones
　　This can enhance the sound transmission gain of the microphone and ensure sufficient loudness for the audience. Microphones for outdoor performances are often far from the mixing console, so it is advisable to use wireless microphones for sound pickup appropriately. If the outdoor wind exceeds level 3, a windscreen can be installed on the microphone. The windscreen is made of a special porous and breathable foam, which has little impact on the frequency response and only slightly reduces sensitivity. This can be adjusted via the GAIN knob on the mixing console to maintain the sound transmission gain. If there is light rain outdoors and the performance must proceed, do not cover the microphone with a plastic bag, as it prevents sound waves from directly acting on the microphone's diaphragm and severely damages the frequency response. It is better to install a supporting umbrella for the microphone to protect it from rain. If it rains heavily, the performance can be terminated directly.

03 Hoisting Loudspeakers
　　Loudspeakers for outdoor artistic performances should not be placed too low. Low-position loudspeakers are prone to sound absorption by the audience's bodies, causing grazing incidence absorption, which results in significant loss of mid and high frequencies in particular. Therefore, loudspeakers should be installed by hoisting, including mid-range or high-frequency horns and outdoor-specific loudspeakers (equipped with high-power high-frequency horns inside). This allows the sound waves from the loudspeakers to travel farther in the air and ensures sufficient loudness for the audience.
　　
04 Protecting Loudspeaker Cables
　　The distance between power amplifiers and loudspeakers is usually long in outdoor performances. To prevent failures and amplifier damage caused by open or short circuits in loudspeaker cables, special personnel should be assigned to protect the loudspeaker lines. The output impedance of power amplifiers is very low, only a few ohms, but the sound power is large, so the current is also relatively high. This cable should not be excessively long, and its cross-sectional area should not be too small to avoid unnecessary sound power loss. If conditions permit, the power amplifier can be placed close to the loudspeakers to reduce unnecessary losses.

05 Protecting Power Cables
　　The energy of the audio system comes from the power grid. If the power circuit fails, the audio system will malfunction. Therefore, the power circuit should be technically supported by local professional electricians. Special security personnel should protect the entire line from the mixing console to the indoor circuit breaker or temporary generator truck.
　　
06 Maintaining Close Communication
　　The sound engineer should keep in touch with assistants in the audience area via walkie-talkies, enabling the sound engineer to grasp the sound effect in the audience area more accurately and timely for prompt adjustments.