Weak current College】 【acoustic basics (4).

<br> 151. the low-frequency sound determines the sound of a manly, chubbiness <br> <br> 152. the audio of the low frequency band decided to voice strong strong <br> <br> 153. wave line refers to .the direction of wave propagation <br> <br> 154. echo is caused by the acoustic reflex <br> <br> 155. the room sound field design, room walls with sound absorbing performance sound-absorbing materials, the stronger the early reflections .and the less extent, the shorter the reverberation time <br> <br> 156. sound absorption coefficient α smaller objects, the greater its reflections. Sound absorption coefficient, the larger objects, the smaller its reflections <br> <br> 157. .the effect of early reflections are giving a warm feeling <br> <br> 158. the interior decoration was completed, if its natural reverberation time T60 partial long, you can use Windows retrofitting heavy fabric curtains to improve <br> <br> 159 .. in a large auditorium design on near-time reflections should make full use of <br> <br> 160. the mixed sound and early reflections two sound coordination with the sounds sound more fullness feeling. <br> <br> 161. the .sound pressure level and sound intensity level the values were the same <br> <br> 162. the phenomenon of acoustic colouring has a detrimental effect on the sound reinforcement <br> <br> 163. indoor sound frequency transmission characteristics and sound absorption coefficient .for around objects <br> <br> 164. the tone and sound frequency directly related <br> <br> 165. the different room room equalization curve is not the same <br> <br> 166. the point source of sound intensity .and distance into relation inverse square <br> <br> 167. the sampling frequency must be better than being sampled signal maximum frequency by more than two times <br> <br> 168. the lower the frequency of wave, the stronger its diffraction .effect <br> <br> 169. acoustic power of no Akira Pi <br> <br> 170. the sound pressure level in dB per unit for the <br> <br> 171. the sound intensity measured in watts/m2 < .br> <br> 172. the sound pressure units for PATA (Pa) <br> <br> 173. the sound source and listen to the sound mixer to movement, listening to the sound of people will feel sound source the frequency change, .this phenomenon is called the Doppler effect <br> <br> 174. the direct sound after delay and phase 180 degrees, overlaid on the direct sound, so that the human ear impression produced space, known as Lloyd's effect <br> <br> .175. the difference between people with the same frequency and the same level of two different sound subjective feeling, called tone <br> <br> 176. the sound of three factors, the frequency of main and sound related elements called tone <br> .<br> 177. the pitch of the voice, as the distance between the interval <br> <br> 178. the sound to be arranged according to a certain interval, called scales <br> <br> 179. instantaneous voltage variation with .time for sinusoidal signal, called pure tone signal <br> <br> 180. It consists of a series of intermittent and duration have certain requirements, each column contains a certain number of wave sine wave composition of pulse signal, known as quenching vocalization < .br> <br> 181. contains various 20Hz to 20kHz frequency components, and the frequency of energy distribution is uniform noise signal, called white noise <br> <br> 182. contains various 20Hz to 20kHz frequency components and the power spectral density and .frequency is inversely proportional to the noise signal, called pink noise <br> <br> 183. the two directivity to heart-shaped or non-directivity of the microphone away from the head of the distance between the two ears, and the stronger the .rake deng Po-stereo format / B Mulan hunting <br> <br> 184. the two microphone combo-one, one-directional microphone for 8 glyphs, the main point to the left side; the other heart-shaped or non-directivity .microphone point to positive. Adds two microphone signal access matrix "and" and "bad" transformed output, called M / S-stereo system <br> <br> 185. the two directivity to heart-shaped or 8 glyphs microphone head, a .dip and installed on the same microphone shell, the angle between the spindle in the 0-360 degree-changes, known as X / Y-stereo system <br> <br> 186. a point in the room reaches the ear heard the order .to direct sound, near-time reflections, mixed noise <br> <br> <br> <br>.