A small room coloration phenomenon - low-frequency hum sound problem2
Studies have shown that the effective elimination of coloration and simple way is to increase the average room absorption coefficient and reduce the frequency of the corresponding stained bands appear simple vibration mode of energy. Under normal circumstances, when the room is greater than the average absorption coefficient of 0.3, the small room sound dyeing is no more. In fact, this is a low-frequency reverberation time is limited. The results have been for the British Broadcasting Corporation and the Japan Broadcasting Association confirmed. In recent years, workers in the film recording the application of this result, his work has also successfully solved the problem coloration. For example, smaller than 196 cubic meters of the room, when the indoor average absorption coefficient of 0.3, the corresponding reverberation time is not greater than 0.3 seconds. If the room larger, when the reverberation time will be lengthened, for example, when the room volume is greater than 500 cubic meters, the reverberation time can be more than 0.5 seconds. If there is low-frequency humming sound coloration in to find out the frequency, the resonance absorption structure can be eliminated. It is not difficult to understand. In previous discussions, the assumption that indoor side interface is rigid, so the corresponding to a particular frequency, Jane Jane is not only the width of the narrow vibration mode, and strength, which is equivalent to a simple oscillator circuit when the maximum value of Q - situation. Increase the damping, that is, to increase the absorption of the room, you can show a wide resonance peak width of the weakened its peak height, which makes a certain width of the simple vibration mode overlapping and cover the entire frequency range. This is the room sound absorption by increasing the fundamental basis for the Elimination of coloration.Appears in a small room sound coloration phenomenon, in addition to the factors that the room itself, but also to the sound source, as well as the sound source and the location of the microphone. The sound source, it is the way the room simple vibration excitation source, while the dialogue is a recording studio programs in languages of the main spectral properties of language can not but have a major impact on the coloration of the. From such studio prone to coloration of the frequency distribution, coloration and voice fundamental frequency and vowel formant closely related. Experimental measurement results show that the English male voice vowel fundamental frequency was 124 Hz a 141 Hz, the first formant around 270 Hz. This is the BBC's research department of language material in English male voice studio in the language of sound measured in the major stained band. It can be inferred, for English female voice is concerned, if there is coloration, its main stained bands corresponding frequencies will be increased due to be improved. Girls of the corresponding values were 210 Hz a 235 Hz, and 3l0 Hz, so the frequency of possible coloration is estimated between 200 Hz a 300 Hz. This shows that in the same recording room, due to the different types of sounds and language, there is also the possibility of coloration will be different. The Mandarin, the vowel fundamental frequency and first formant values with the corresponding English, there is significant difference. Test results show that male Mandarin base-band and the first formant, respectively. 200-210 Hz and 290-1000 Hz; still in the lower frequency range, but the possibility of staining appeared sound will be somewhat reduced, while the female voice Mandarin base-band (310-320 Hz) and the first resonance Bee, (320-1280 Hz) are 300 Hz and above, there are slim chances of coloration of the.