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Appendix
Appendix
Types of sound
fig.RevExp01.eps
The sound you normally hear is divided into three types: “direct sound,” “early reflections,” and
“reverberation.” The “direct sound” is the sound that reaches the listener directly from the source. “Early
reflections” are sounds that have reflected one to several times from the walls or other surfaces of the room.
“Reverberation” is sound that has reflected many times before reaching the listener.
How sound and time are related
fig.RevExp02.eps
The reflected sounds reach the listener in the following order. The pre-delay is the time from when the direct
sound is heard until the reverb arrives. The reverb time is the duration until the reverb disappears.
Tonal character of reverb
The tonal character of reverb is affected by the material of the walls and other reflective surfaces. This is
because the reflectivity of the surfaces will affect the proportion of high and low frequencies that are reflected.
You can use the DFP (Damp Filter) to vary this property of the sound. The high-frequency range or low-
frequency range of the reverb will be attenuated as you decrease the value of the HI FREQ DAMP GAIN or
LO FREQ DAMP GAIN parameters, respectively.
If you want to produce soft-sounding reverb, lower the HI FREQ DAMP FREQ. If you want to produce crisp-
sounding reverb, raise the LO FREQ DAMP FREQ.
source
listener
direct sound
early reflections
reverberation
level
direct sound
time
pre-delay
reverb time
reverberation
early reflections
M-400_v15_e.book 226 ページ 2008年6月20日 金曜日 午後4時5分