The six-step wireless management method provides you with wireless security services.
Step1:
Perform a static RF scan of the on-site wireless environment, and arrange the frequency band where the wireless system is located to avoid the existing interference in the field
Step 2:
The design and arrangement of the antenna system are carried out according to the overall arrangement of the lighting and dance beauty to ensure the comprehensive and accurate coverage of the antenna.
Step 3:
Confirm the number and type of channels of wireless devices. All brands of wireless microphones and other types of wireless devices on site need to be registered by us for subsequent coordination.
Step4:
Wireless frequency planning and coordination, which is a very important part of RF management. A successful coordination meeting can greatly facilitate work.
Step5:
Make equipment and frequency adjustments (if necessary) during rehearsal and monitor during performances.
According to CueSheet, monitor the signal strength and audio quality of upcoming and in-use wireless microphones in advance.
On February 23, the 2017 Honor of Kings(HoG) Autumn Finals were held at the “Spring Cocoon” Gymnasium of China Resources Shenzhen Bay Sports Center. As the official professional event of the highest standard of Honor of Kings, the venue was full of seats and thunderous applause. The peak showdown between QGhappy and XQ ignited the enthusiasm of the audience.
Such a high-level event site is naturally indispensable for our wireless team. A 16-channel SHURE ULXD digital wireless system and a 2-channel SHURE top-of-the-line Axient Digital were used for the host and performers. Designed by Mr. Mingcong and guarantees the smooth operation of the wireless system.
Source of On-Site Interference
At the site of this large-scale event, the wireless environment is extremely complex. LED floor screens, lighting controls, complex stage equipment and other wireless equipment have caused certain interference to our wireless microphones.
In-Ear Monitor (IEM)
A total of 4-channel Sennheiser IEMs are used in the scene, and there is a huge gap between the background noise of the scene in the case of full on and full off.
IEM all-off on-site spectrogramTurn on 1 channel IEMTurn on 4 channel IEMs
From the picture, it is not difficult to see that the IMD between these IEM channels has a great impact on the wireless environment of the scene, which seriously reduces the available frequency band of the wireless microphone.
Intercom system
In addition, due to the particularity of e-sports competitions, smooth communication between players is very important, so the priority of the on-site intercom system is higher than that of wireless microphones.
However, the intermodulation distortion of the intercom system greatly interferes with the frequency band where the wireless microphone is located.
400-600MHz spectrum when the intercom system is off400-600MHz spectrum when the intercom system is on
As shown in the figure, after the wireless intercom system is turned on, the frequency to which the wireless microphone belongs is largely occupied. If the channel frequency used by the wireless microphone happens to be the intermodulation distortion frequency of the wireless intercom, the frequency drop phenomenon will occur, which further increases the difficulty of frequency planning.
The distance between the IEM transmitting & receiving antenna of the wireless system
The distance between the IEM transmitting antenna and the wireless system receiving antenna is different, and the impact on the noise floor of the site is also different. The closer the distance is, the higher the intensity of the noise floor of the scene, and the farther the distance is, the weaker the noise floor is.
The spectrum diagram of the distance between the transmitting antenna and the receiving antenna is 2.4 metersThe spectrum diagram of the distance between the transmitting antenna and the receiving antenna is 1.2 meters
It can be seen that at the performance site, we need to increase the distance between the ear return transmitting antenna and the wireless system receiving antenna as much as possible.
The key to solving the frequency drop phenomenon of wireless microphones is actually to improve the signal-to-noise ratio of wireless systems. Improving the signal-to-noise ratio usually starts from two aspects.
The main reasons for the high RF noise floor of the HOG finals are the interference of the large LED screen and the intermodulation distortion of the intercom system. Due to transportation costs, the back covers of many LED large-screen circuits have been removed, so that the original electromagnetic shielding has been destroyed, resulting in strong electromagnetic interference. Therefore, we must first check whether the back is covered with a shielding layer. If not, we To wrap the circuit section with aluminum foil. Then we need to check if the LED controller has any free output ports. If so, we need to plug it in with a terminal or wrap it in aluminum foil as well.
Video output port without Terminal may transmit RF signals
Another problem that needs to be solved is the serious intermodulation distortion of the on-site intercom system. First, we need to recalculate the frequency of the wireless system when the intercom system is turned on.
Then, according to the situation on site, we can widen the distance between the intercom transmitting antennas to reduce the intensity of intermodulation distortion interference. Through the above steps, the noise floor condition of the site has been improved.
Increase the signal strength of the channel
First of all, we need to check whether the placement of the receiving antenna is reasonable. If it is not reasonable, we must adjust the placement of the receiving antenna to shorten the distance between the receiving antenna and the transmitting antenna as much as possible. In addition, we can use strong directional antennas such as Shure HA8089 according to scene conditions
China’s first “drifting multi-dimensional experience drama” “Zhiyin” was built by the famous director Fan Yue and his team in two years. It is a real cruise ship with a length of 120 meters that is completely restored to the appearance of the last century and can travel freely on the Yangtze River. , turned into a mobile theater. Such an innovative form of performance undoubtedly poses a major challenge to the transmission of wireless audio signals. We answered this challenge perfectly with the excellent digital audio and signal stability of the Shure ULX-D digital wireless system.
The prototype of the “Zhiyin” mobile theater came from the “Jianghua Wheel” of Wuhan Minsheng Company at the beginning of the last century. The director team required the wireless signal to cover the entire ship in all spaces, and at the same time to achieve good sound quality. In the face of a special pickup environment, we create an immersive scene for the scene by utilizing the spectral efficiency of the ULX-D digital wireless system, long transmission distance, and the ability to restore audio signals without distortion in relatively high RF noise. sound experience. It is the unique advantages of these digital wireless systems that can successfully help the director team realize the sound pickup requirements of this experience play.
The prototype of the “Zhiyin” mobile theater came from the “Jianghua Wheel” of Wuhan Minsheng Company at the beginning of the last century. The director team required the wireless signal to cover the entire ship in all directions, and at the same time to achieve good sound quality.
Facing the special sound pickup environment, we create an immersive sound experience for the scene by utilizing the spectral efficiency of the digital wireless system, the long transmission distance and the ability to restore the audio signal without distortion in the relatively high radio frequency noise.
Since the application environment of the wireless system is on a cruise ship, we have designed a solution to achieve seamless full coverage of the radio frequency signals in the three-layer cabin, ensuring that the wireless pockets used by any actor can be used in any one inside and outside the cabin. You can have a stable RF signal and a good audio signal in every corner. This is the first time we have done such a large-scale wireless signal coverage project on a cruise ship. The cabin is about 90 meters long and 20 meters wide. The three deck cabins cover a total area of more than 6,000 square meters. The RF cable used is about 2000 meters long.
To achieve full coverage in the cabin, we use a distributed antenna system. With such a large-scale antenna coverage, the choice of point position is actually a trade-off. It is necessary to meet the requirements that the antenna signal can cover the entire cabin, and to consider the use of feeder lines as little as possible. Even if a feeder with very low line loss is used, since the area to be covered is so large, each additional feeder will bring more losses. In the end, we carefully selected 6 points in the middle, rear and sides of the cabin on each floor to achieve a good balance between the minimum line loss and the maximum coverage area.
