現在,大多數會議室和劇院都有一個標準配置,即聲音,它有許多用途。關于這個問題沒有必要多說。但是除了這些用途之外,聲音還會受到干擾嗎?會議現場設備包括會議終端及相關外部設備,設備類型及功能基本相同。因此,會議音響信號的傳輸過程分為兩部分:
Nowadays, most conference rooms and theaters have a standard configuration called sound, which has many uses. There is no need to say more about this issue. But besides these purposes, will sound still be disturbed? The on-site equipment for the conference includes conference terminals and related external devices, with similar types and functions. Therefore, the transmission process of conference audio signals is divided into two parts:
這一端的聲音由麥克風拾取,人聲被轉換成電信號并發送到混音器。經過放大、混音、分配、音質修改和效果處理后,分為兩個通道:一個通道的信號被送到該端的功率放大器進行放大,然后由揚聲器恢復為聲音;另一端由混音器放大,然后由揚聲器(aux)輸出。
The sound at this end is picked up by the microphone, and the human voice is converted into an electrical signal and sent to the mixer. After amplification, mixing, distribution, sound quality modification, and effect processing, it is divided into two channels: the signal from one channel is sent to the power amplifier at that end for amplification, and then restored to sound by the speaker; The other end is amplified by a mixer and then output by a speaker (AUX).
另一部分:會議終端對遠端發送的信號進行處理后,會議音響信號進入混音器進行處理,然后送到本地端的功率放大器進行放大,由揚聲器恢復成聲音。根據以上分析,混頻器是各個信號處理過程的匯合點。如何調整混音器的各個鍵和功能鍵是調試的關鍵。
Another part: After the conference terminal processes the signal sent from the remote end, the conference audio signal enters the mixer for processing, and then is sent to the local power amplifier for amplification, which is restored to sound by the speaker. According to the above analysis, the mixer is the convergence point of various signal processing processes. How to adjust the various keys and function keys of the mixer is the key to debugging.
在會議音響信號傳輸過程中,存在著許多干擾,如電源干擾、設備干擾、光干擾等。
There are many interferences in the transmission of conference audio signals, such as power interference, equipment interference, light interference, etc.
1.電源干擾
1. Power interference
電源接地不良、設備間地線接觸不良、阻抗不匹配、電源未凈化處理、音頻線與交流線敷設在同一管道、溝渠或橋架內,會對音頻信號產生雜波干擾,形成低頻交流“嗡嗡”聲。
Poor grounding of the power supply, poor contact of ground wires between equipment, impedance mismatch, untreated power supply, and the laying of audio and AC lines in the same pipeline, ditch, or bridge can cause noise interference to the audio signal, forming low-frequency AC "buzzing" sound.
2.設備間干擾
2. Equipment to equipment interference
“口哨”是由揚聲器和麥克風之間的正反饋引起的。主要原因是話筒離揚聲器太近或話筒指向揚聲器。當聲源延遲時產生“空聲”。例如,話筒不僅拾取聲源信號并接收放大和恢復的信號,或者兩個與聲源距離不同的話筒拾取同一聲源的信號,或者一個話筒的信號會產生相應的延遲。這些信號疊加后,一些頻率分量將相互抵消,從而產生“空音”。
Whistle "is caused by positive feedback between the speaker and microphone. The main reason is that the microphone is too close to the speaker or the microphone is pointing towards the speaker. When the sound source is delayed, "empty sound" is generated. For example, microphones not only pick up sound source signals and receive amplified and restored signals, or two microphones with different distances from the sound source pick up signals from the same sound source, or the signal from one microphone will generate corresponding delays. After these signals are superimposed, some frequency components will cancel out each other, resulting in "empty sound".
3.照明干擾
3. Lighting interference
現場鎮流器間歇啟動的照明燈在燈管激發時會產生高頻輻射,并通過麥克風及其引線串聯,產生“dada”聲;如果話筒線太靠近燈線,也會發出“吱吱”聲;此外,還會發生高頻電磁干擾。
The lighting lamp that is intermittently activated by the on-site ballast will generate high-frequency radiation when the lamp tube is excited, and it will be connected in series through the microphone and its leads to produce a "dada" sound; If the microphone cable is too close to the light cable, it will also make a "squeaking" sound; In addition, high-frequency electromagnetic interference may also occur.
要恢復視頻會議音響的聲音,應根據聲學的理論知識和不同的實際情況,靈活調整混音器和均衡器,對聲音進行處理和美化,彌補聲場的缺陷,創造理想的聲學環境;適當調整壓縮限制器,避免在突然出現大峰值信號時過載和不平衡,以彌補聲場的不足,創造理想的聲學環境。
To restore the sound of the video conference audio system, it is necessary to flexibly adjust the mixer and equalizer based on the theoretical knowledge of acoustics and different actual situations, process and beautify the sound, compensate for the defects of the sound field, and create an ideal acoustic environment; Adjust the compression limiter appropriately to avoid overload and imbalance in the event of sudden high peak signals, in order to compensate for the shortcomings of the sound field and create an ideal acoustic environment.
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