Small Room Acoustics
360 likes | 463 Vues
Explore the fundamental principles of sound waves, room acoustics, and absorption techniques tailored for small rooms. Learn about low frequency management, resonators, diffusion, and microphone/loudspeaker placement strategies to maximize sound clarity and minimize spatial constraints. Adapt your design to cater to small room dimensions and leverage this comprehensive tutorial to improve your audio experience.
Small Room Acoustics
E N D
Presentation Transcript
Small Room Acoustics Ben Kok Nelissen ingenieursbureau b.kok@nelissenbv.nl AES tutorial, 2008
Introduction • What is a sound wave? AES tutorial, 2008
Sound wave AES tutorial, 2008
Sound wave F = 100 Hz → λ = 3,4 m F = 1 kHz → λ = 0,34 m F = 10 kHz → λ = 0,034 m AES tutorial, 2008
When do we consider a room ‘Small’? AES tutorial, 2008
Small Rooms • Living Room • Recording Studio • Control Room • Car • Telephone Booth • Headphone AES tutorial, 2008
Low frequencies in an enclosure AES tutorial, 2008
Low frequencies in an enclosure AES tutorial, 2008
Low frequencies in an enclosure “Golden” ratios: ASHREA 1:1.17:1.47 ASHREA 1:1.45:2.10 Bolt 1:1.28:1.54 IAC 1:1.26:1.60 Seppmeyer 1:1.14:1.39 Kok 1:1.12:1.41 AES tutorial, 2008
Room mode analysis AES tutorial, 2008
absorption • porous material • resonators • sandwichconstructions AES tutorial, 2008
porous material AES tutorial, 2008
porous material AES tutorial, 2008
porous material AES tutorial, 2008
porous material Rule of thumb: AES tutorial, 2008
resonator AES tutorial, 2008
diafragmatic resonator AES tutorial, 2008
diafragmatic resonator • flexible panels • thin • large • high internal loss • excited over the fullarea AES tutorial, 2008
Helmholtz resonator AES tutorial, 2008
diffusion spatial and temporal distribution of energy AES tutorial, 2008
Specular reflection AES tutorial, 2008
Diffuse reflection 1 AES tutorial, 2008
Diffuse reflection 2 AES tutorial, 2008
diffuser example AES tutorial, 2008
diffusion repetition of the same sequence should be avoided!! > grating lobes! AES tutorial, 2008
phase modulated array of diffusers AES tutorial, 2008
installation example AES tutorial, 2008
microphone/ loudspeaker placement • early reflections (1st 10 ms) cause coloration • specular reflections (narrow peak) cause comb filtering • diffuse reflections add ‘warmth’ AES tutorial, 2008
microphone/ loudspeaker placement • distant micing/ listening allows sound to develop • close micing/ listening minimizes room influence • a small room has no statistic sound field, strong variation between positions can exist AES tutorial, 2008
microphone/ loudspeaker placement • room modes have a significant influence on low frequency coupling; loudspeaker position can have a strong influence on low frequency response • distributed sub-woofers can create a smoother low frequency response • a small room has no statistic sound field, strong variation between positions can exist AES tutorial, 2008
conclusion • a small room behaves different because it’s dimensions are similar to the wavelength of the (re)produced sound • source and listening positions often are fixed -> the design can accommodate for this • changing positions can have a dramatic influence AES tutorial, 2008
QUESTIONS AES tutorial, 2008