Abbingdon Music Research Reference Class Proffessional Monitor LS-77 - Manual (Page 52)

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How does the standing waves influence the sound
field? - The curve expresses the area of the room
where the actual frequency is audible. At the minima
the frequency is represented at a much lower level
(sometimes -40 dB compared to the maximum). If
the room has the same dimensions as length, width,
and even height it is very problematic to obtain an
even sound distribution. How to prohibit standing waves - Parallel walls in
the room should be prevented if possible. Then the
strongest modes are suppressed. This obviously
requires purpose built rooms. When placing the
speakers it is important that as few modes as possible
are excited. This is why the speakers should not be
placed in a maximum of a standing wave, nor should
the listener be located in a maximum or minimum of
a standing wave.
2 8m .
6 7m .
Undesirable Listening Positions
1 0 0 25Hz , , ( )
4 0 0 100Hz , , ( )
3 0 0 75Hz , , ( )
2 50 , , ( ) 0 0 Hz
0 0 Hz , , ( ) 1 62
2 8m .
6 7m .
Desirable Listening Positions
1 0 0 25Hz , , ( )
4 0 0 100Hz , , ( )
3 0 0 75Hz , , ( )
2 50 , , ( ) 0 0 Hz
0 0 Hz , , ( ) 1 62