User Manual

Speaker System Design Guide for
Yamaha Sound System Simulator
directly, and the sound pressure levels rise as a result of the speaker directivity. The
measured results for 2 kHz stop attenuating after 13 m, just like the results for 1 kHz.
Also, the effects of speaker directivity on the levels are hidden by the effects of the
reflected sound.
When configuring a speaker system based on computations of direct sound, it is
important to remember that at the actual venue, steady-state SPL will rise at more
distant points as a result of sound diffusion. If you fail to take this point into account
when trying to achieve specific SPLs at more distant points, you may be misled by the
computed results into selecting a system whose overall SPLs are much larger than
necessary. The point at which level attenuation caused by distance is mitigated varies
depending on the size and sound absorption conditions of the venue. Formulas for
determining theoretical values such as those shown in figure 10 have been proposed
by researchers.
-15
-10
-5
0
0 5 10 15 20 25
Distance (m)
Level (dB)
Meas 1kHz
YS3 1kHz
-15
-10
-5
0
0 5 10 15 20 25
Distance （m）
Level (dB)
Meas 2kHz
YS32kHz
Figure 9: Comparisons of level attenuations caused by distance
Top: relationship between the sound source and the points of measurement.
Bottom: measured and computed results.
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