Page 63 - The Master Handbook Of Acoustics

38 CHAPTER TWO

Example
If 446 Hz is the lower edge of a ⁄3 octave band, what is the frequency of
1
the upper edge?
f 2 1/3
=2
446
1/3
f 2 = (446) (2 )
f 2 = (446) (1.2599)
f 2 = 561.9 Hz

Example
What is the lower edge of a ⁄3 octave band centered on 1,000 Hz? The
1
1 1
f 1 is 1,000 Hz but the lower edge would be ⁄6 octave lower than the ⁄3
octave, so n = ⁄6:
1
f 2 1,000 1/6
= = 2
f 1 f 1
1,000
f 1 =
2 1/6
1,000
f 1 =
1.12246
f 1 = 890.9 Hz

Example
At what frequency is the lower edge of an octave band centered on
2,500 Hz?

2,500 1/2
=2
f 1
2,500
f 1 =
2 1/2
2,500
f 1 =
1.4142
f 1 = 1,767.8 Hz
What is the upper edge?
f 2 1/2
= 2
2,500