Trane TRG-TRC007-EN Manuale Utente
8
TRG-TRC007-EN
notes
period one
Fundamentals of Sound
Middle ground between octave-band analysis and full-spectrum analysis is
provided by one-third octave-band analysis. One-third octave bands divide
the full octaves into thirds. The upper cutoff frequency of each third octave is
greater than the lower cutoff frequency by a factor of the cube root of two
(approximately 1.2599). If tones are contained in the broadband sound, they will
be more readily apparent in the third octaves.
provided by one-third octave-band analysis. One-third octave bands divide
the full octaves into thirds. The upper cutoff frequency of each third octave is
greater than the lower cutoff frequency by a factor of the cube root of two
(approximately 1.2599). If tones are contained in the broadband sound, they will
be more readily apparent in the third octaves.
The use of octave bands is usually sufficient for rating the acoustical
environment in a given space. One-third octave bands are, however, more
useful for product development and troubleshooting acoustical problems.
environment in a given space. One-third octave bands are, however, more
useful for product development and troubleshooting acoustical problems.
One-Third Octave Bands
am
pl
itud
e
am
plit
ud
e
frequency, Hz
frequency, Hz
1,000
1,000
125
125
500
500
250
250
2,000
2,000
4,000
4,000
8,000
8,000
63
63
Figure 10