Listening Distance & Sound Pressure Level

Direct sound dominates
Within this distance the direct sound from the monitor has a higher level
than the reverberant sound in the room. Placing the monitor within this
distance range is advantageous in minimizing the tendency of the room
reverberation to change the character of the monitored sound colour
and affect the precision of stereo imaging. The level of the direct sound
relative to the reverberant sound progressively reduces as the distance
to the monitor increases.
Critical distance
The critical distance is the distance where the direct sound from the
monitor and the reverberant sound in the room have equal level in
midrange frequencies (approximately between 200 Hz and 4 kHz).
The critical distance is affected by the room volume, the room
reverberation time (referred to ITU-R BS.1116-1 Recommendation),
and the directivity of the monitor.
3
55 m
3
1'950 ft
0.21 s
3
65 m
3
2'300 ft
0.22 s
3
75 m
3
2'650 ft
0.23 s
3
65 m
3
2'300 ft
0.22 s
3
75 m
3
2'650 ft
0.23 s
3
75 m
3
2'650 ft
0.23 s
3
85 m
3
3'000 ft
0.24 s
3
85 m
3
3'000 ft
0.24 s
3
95 m
3
3'400 ft
0.25 s
3
95 m
3
3'400 ft
0.25 s
3
110 m
3
3'900 ft
0.26 s
3
110 m
3
3'900 ft
0.26 s
3
125 m
3
4'420 ft
0.27 s
3
120 m
3
4'250 ft
0.26 s
3
170 m
3
6'000 ft
0.29 s
3
200 m
3
7'100 ft
0.31 s
3
400 m
3
14'200 ft
0.43 s
Reverberant sound dominates
At these distances the reverberant sound in the room has a higher level
than the direct sound from the monitor. This balance progressively
increases as the distance from the monitor increases.
The monitor can be used in these distances, but the sound character is
strongly affected by the reverberation characteristics of the room, and
this has a progressively increasing effect on the sound colour and
stereo imaging accuracy.
Not recommended distances
When the distance to the monitor is too short, summing of sound from
multiple drivers is not happening as designed, and this affects the
flatness of the frequency response. A flatter and more stable frequency
response is obtained at a larger distance.
Distance from the monitor (meters, feet)
3
85 m
3
3'000 ft
0.24 s
3
95 m
3
3'400 ft
0.25 s
Genelec Monitors
Direct Sound Dominance
Guide 2
Room volume
Room reverberation time (RT60)
3
55 m
3
1'950 ft
0.21 s
(m)1 1.5 2 5 10 153
3.2 5
6.5
16.5 32 50 (ft)
9.8
1238CF/DF
1238
1234
1236
1.6
8320
8030
8040
8050
1032
8260
8351
8020
8010
8330
M030
M040
Genelec product models
0.5
8340
8350
1237
0.3
1.0