Chief Tuner Zhang Jing: For the first time, the stereo effect was tried to cover the Tiananmen Tower

"Ensuring the uniformity, clarity and completeness of the sound on the scene is always the biggest test we face." As a senior engineer of the Technical Bureau of the Central Radio and Television Corporation, Zhang Jing once again assumed an important role as the main tuner of the sound support command, which was the fourth time in his career that he fought in the main sound reinforcement room.

In the major events in Tiananmen Square, the most important task of sound protection is sound reinforcement, and the difficulty of sound reinforcement is in the hut where Zhang Jing is located — because all sound is sent out from here. Unlike the sound guarantee for the 70th anniversary celebration of the founding of the People's Republic of China in 2019, although there is no military parade and mass parade at this year's celebration, this does not mean that the sound guarantee has become easier.

"Tens of thousands of people listened to the leaders' speeches at the scene, and the audience area went north to the east-west platform of the city tower and the south to the vicinity of the Monument to the People's Heroes, so to ensure that so many spectators could hear clearly, how to overcome the mutual coverage and interference of sounds was a major problem." Zhang Jing said that the performance area and the audience area are separated from the general performance, and the military band, choir and dedication group are distributed in the audience area in this activity, which brings greater challenges to the sound pickup and sound reinforcement guarantee.

The square has the largest audience, so in the square area, only the method of zoning sound reinforcement can be adopted, that is, each area is covered with small speakers. Zhang Jing said that because the audience seat in the square area looks "one horse pingchuan", the seats have no slope, and the speakers cannot be hoisted, so a total of 80 groups and 320 mobile speakers have been arranged in the square area to ensure that the sound can be evenly covered, so that all the audience can clearly hear the speech on the city tower and the sound of the military band playing.

In the viewing platform area north of Chang'an Avenue, this year the security team optimized the angle of sound coverage to control the sound pressure to about 2dB (decibels). That is to say, whether it is the front row or the back row audience, everyone will sound more comfortable, and the sound is almost undifferentiated, thus avoiding the problem of large front row sound and small rear sound.

For the tiananmen city tower area, which is the most important thing, mono sound effects have been used in the past, but this year, the security team tried to use stereo effect coverage for the first time. For the listener, it will produce a kind of sound effect like watching a movie in a movie theater, which sounds more comfortable. Zhang Jing said that the technology of the stereo effect itself is not difficult, but because the speakers in the Tiananmen Tower area cannot be arranged in the way of general concert hanging, they can only be placed on the ground, so that the sound spreads from below the city tower to the top of the city tower, which will be subject to many restrictions such as height and distance. Over the course of time, the team has repeatedly tested and adjusted to achieve the best results.

"This time it's not an ordinary show. The venue is not only large, but also completely open, and there is no sound project to refer to in the world. Zhang Jing said that in addition to technical problems, audio support also faces a major challenge, that is, because the activity is held in Tiananmen Square, most of the time the sound debugging can not be "sound" operation, so the rehearsal time left for the support team is very precious, and can only take advantage of the opportunity of the previous two drills. "For us, the drill is an assessment, and we only have two opportunities to fully set up the sound system and debug it." Zhang Jing introduced that in the face of such strict guarantee conditions, the whole team needs to do a lot of plans. The sound support command and the on-site support team of nearly 400 people supporting manufacturers, through a "brainstorming", imagine the problems that may occur in each link and scene, and then find out the response methods one by one, and the ultimate purpose is to ensure that the sound guarantee is foolproof.

Source: Beijing Daily Client | Reporter Sun Jie Intern reporter Shi Yue

Editor: Yang Meng

Process Editor: Dan Guo