. Elements of acoustical engineering. Electro-acoustics; Sound. 300 ARCHITECTURAL ACOUSTICS panel loud speaker is employed. At the present time the favored position for the loud speaker appears to be in the instrument panel because in this location the radio receiver, loud speaker, and controls may be combined into a single compact unit. The distribution of sound is excellent in the front seat and good in the back seat. The stiffness presented to the back of the cone is small because the entire radio receiver case volume is used to enclose the back of the loud speaker. Therefore, the response
. Elements of acoustical engineering. Electro-acoustics; Sound. 300 ARCHITECTURAL ACOUSTICS panel loud speaker is employed. At the present time the favored position for the loud speaker appears to be in the instrument panel because in this location the radio receiver, loud speaker, and controls may be combined into a single compact unit. The distribution of sound is excellent in the front seat and good in the back seat. The stiffness presented to the back of the cone is small because the entire radio receiver case volume is used to enclose the back of the loud speaker. Therefore, the response may be maintained in the low frequency range. In order to reduce annoyance from hiss generated in the receiver due to the relatively weak signals ( ..0004. 70 80 90 100 AT 20" CENTIGRADE Fig. Curves showing the absorption of a plane sound wave in passing through air, at 20° C. for different frequencies, as a function of the relative humidity. The intensity after a plane wave has travelled a distance x centimeters is /oe~'"^, where h is the intensity at;(: = 0 and m is the coefficient given by the above graph. (After Knudsen.) delivered by the antenna, it is customary to attenuate the response above 4500 cycles. The low frequency response in reproduction is usually masked at the higher speeds by wind noise and road rumble. Also see Sec. \\3A1. L. Absorption of Sound in Passing Through Air. — The absorption ^^ of a plane progressive sound wave in passing through air may be several times that predicted by the classical theory. The anomalous absorption is primarily dependent upon the humidity, although it is also affected by im- purities such as H2O, H2, H2S and NH3. This, of course, means that there may be considerable frequency discrimination of the reproduced sound in large theatres where the sound travels a long distance. In addition, the reverberation time will be reduced at the higher frequencies. The co- " Knudsen, V. D., Jour. Acous. Soc. Amer
Size: 1841px × 1357px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
