Abbingdon Music Research Reference Class Proffessional Monitor LS-77 - Manual (Page 47)

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Appendix G - Acoustics Background Information
G.1 Acoustics
When we talk about making a room "sound right", we are probably dealing with room acoustics. As a science
acoustics has been around for about a hundred years. Until then good acoustics happened by experiment, by
experience, or simply by accident.
Today we know a lot about the parameters that influence the "sound" of a room. Talking about the listening room
we know that basically this room should act as neutral as possible. But this is not always the case. Lets just take
a short look on some of the issues that one must be aware of.
G.2 Good acoustics
Here is a list of important parameters concerning good acoustics.
y Proper reverberation time
y Good sound distribution
y Adequate sound pressure level
y Low background noise level
y No echo (flutter echo)
Now lets have a look on these headlines that will be adequate for the most purposes concerning sound production.
G.3 Reverberation time
The reverberation time is defined by the time it takes a sound to attenuate 60 dB after the source is stopped. In
real life we can experience reverb times from approximately 0sec. (outdoors or in anechoic chambers) to
something like 10-12 sec. In special reverb chambers the time may exceed 20 sec. Listening rooms normally
should have a reverb time around 0.2 - 0.3 sec.