Listen to the good voice Condensate positive energy

The overall indoor space area of Jiaozuo No.1 Middle School Gymnasium is about 2,200 m 2, with a total of 2,000 spectators. It is a comprehensive cultural project integrating language, music, multimedia film and television broadcasting, school teachers and students variety performance and other large-scale activities. The JSL to Jiaozuo No. 1 Middle School stadium sound system upgrade, not only using amplification sound professional sound equipment, at the same time according to the stadium building structure on the top arranged a high density glass fiber sound absorption, can minimize the reflection of sound transmission, enhance the stadium sound language clarity and the clarity of music.

一. Comparison before and after the transformation

As view as the main function of large modern buildings, stadium sound system construction is more complex, involving a professional wide, especially under construction, sound, need a high level of technology and professional quality, in the design, procurement, installation, debugging etc. need to design scientific and reasonable, exquisite durable equipment, the installation excellence, accurate and reliable debugging. Before the sound expansion system transformation of Jiaozuo No.1 Middle School Gymnasium, the reverberation time is long, the sound field uniformity is high, the sound reflection is obvious, and the clarity and stability of sound quality are insufficient. Due to the large average free range of sound waves in the museum, which increases the difficulty of low frequency control, special attention is paid to low frequency sound absorption control when choosing sound absorption materials.

After the transformation, the space sound absorption body is installed in the ceiling. When the venue hall is empty, the reverberation time is RT60≈1.70 (seconds). When the field is full, the reverberation time is RT60≈1.50 (seconds). Considering that in the process of decoration engineering, because of the "acoustic loss value" appeared in the construction, it may not be accurate to the calculated value, but it can basically meet the requirements of the acoustic standards of the gymnasium. After JSL team in Jiaozuo a stadium amplification the ceiling layout sound absorbing body belongs to high density glass fiber cotton aluminum alloy wrap material, according to the principle of acoustic delicate processing, meet architectural beautiful at the same time has a wide sound absorption band, can give full play to the role of material absorption, sound transmission close to zero reflection, expanding sound optimization effect is obvious.

Pictures before and after the transformation

Before the transformation

After the transformation

Before the transformation

After the transformation

Before the transformation

After the transformation

Before the transformation

After the transformation

二. Architectural structure and acoustic design

Gymnasium sound system topology diagram

Layout drawing of the sound absorber at the top of the stadium

There are 6 ways of arranging the speakers in the gymnasium, such as centralized, distributed and mixed type. Adopting disperse type layout, sound speaker is from the distance of the audience seat closest, sound clarity is high, sound field is uniform, but sound image consistency is slightly weaker. Adopting the centralized layout, the distance of the speaker box is far away from the audience, in order to improve the clarity of the sound often need to choose the sound box with strong directivity, the sound field distribution is not easy to be uniform, but the sound and image consistency is high. According to the building structure of Jiaozuo No. 1 Middle School in gymnasium, JSL team for the distributed speaker layout, in order to improve the stadium sound quality reduce empty field reverberation time, JSL team is in progress expansion equipment selection and the top sound absorption arrangement design, 24 pcs LA line array as the main sound toward the audience, 10 pcs AT series full frequency speakers and 2 pcs WS ultra low speakers for the main stage, sound intensity increase sound field distribution more uniform, enhance the venue sound system sound and image consistency.

The 12 pcs LA on the left of the stadium and the 12 pcs LA on the right are used to amplify the sound of the left and right auditorium, and the 4 pcs AT in the back auditorium are used for the amplification of the back auditorium.

4 pcs AT are used in midpitch amplification

2 pcs AT positions are arranged on the rostrum, which can be used both for the amplification of the front of the rostrum and for the daily amplification of small performances

2 pcs WS ultra-low speakers are used for low-frequency tonic to enhance the shock of the scene.

Layout drawing of the left-side speaker box of the stadium

Layout drawing of the speaker box on the right side of the stadium

Layout drawing of the speaker box in the back field audience seat

Layout drawing of the podium speaker box

Sound amplification belongs to the category of applied acoustics, and the final effect is the embodiment of the comprehensive effect of construction and electroacoustic. The existence of expanded sound field sound interference will affect the language clarity and music clarity of expanded sound, and damage the sound quality effect of sound amplification and replay. Modern sound expansion design is no longer "satisfied" with the general sense of expanded sound pressure level and sound field uniformity, but pays great attention to the sound interference problem of expanded sound field.

JSL team in Jiaozuo one stadium amplification system design to minimize sound interference, as the focus of the amplification design, through the speaker equipment arrangement and the top of the sound, analysis and calculation stadium amplification reverberation time and frequency response, through multiple measurement debugging has a good acoustic environment, to meet the requirements of the stadium acoustics, must do language dialogue clear, and can truly reflect the sound dynamic, sound quality fullness is high. This project selects medium frequency 500-1000Hz, reverberation time T60≤1.60±0.1s, fast language clarity rasti ≥0.7, sound field inuniformity IP≥± 3~5dB (A), loudness LP ≥75dB (A), which can meet the standard of Architectural Acoustic Design Code for Theater, Cinema and Multi-purpose Hall, and later meet the level one standard of Gymnasium Acoustic Design and Measurement Code.

After the inspection and field test of "Jiaozuo No.1 Middle School Celebrates the 100th Anniversary of the Founding of the Party and Artistic Performance", the main sound expansion system of the museum meets the multi-functional requirements of sports competition, large-scale assembly and artistic performance, and the sound expansion system transformation project of Jiaozuo No.1 Middle School Gymnasium has been successfully concluded.

三. Project actual shooting