Crestron
Surround Sound
Primer
Crestron Surround Sound
Sound, Hearing and the Limits of Perception
Objects produce sound when vibrating in an elastic medium. Solids,
liquids and gas all conduct sound. When something vibrates in the
atmosphere, it pushes the air around it creating an acoustic compression
wave. The trail of this wave creates a drop in pressure, called
rarefaction.
Sound waves, which travel at about 1,086 feet per second (331.1 meters
per second) in the air, have three basic properties, frequency,
wavelength, and volume (amplitude).
Frequency
Frequency is the number of distinct positive or negative sound wave
elements that repeat in one second. Frequency is measured in Hertz
(Hz). A 20 Hz frequency contains 20 positive and negative cycles of
individual components each second (20 distinct waves passing by in
one second). A 20 kHz (kilohertz) frequency contains 20,000 of these
cycles every second.
Frequency (Hz)
Wavelength
Wavelength is the distance between two points on consecutive waves.
It is measured from the same position on a wave in two consecutive
cycles. Wavelength can be measured by taking the horizontal distance
from a point (at the peak in our example) of one wave cycle to the same
point at the peak in the second wave cycle.
Primer – DOC. 6122
Surround Sound
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