Octave band

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https://en.wikipedia.org/wiki/Octave_band

Analyzing a source on a frequency by frequency basis is possible but time consuming[citation needed]. The whole frequency range is divided into sets of frequencies called bands. Each band covers a specific range of frequencies. For this reason, a scale of octave bands and one-third octave bands has been developed. A band is said to be an octave in width when the upper band frequency is twice the lower band frequency. A one-third octave band is defined as a frequency band whose upper band-edge frequency (f2) is the lower band frequency (f1) times the cube root of two.

Contents

• 1Octave Bands
  • 1.1Calculation
  • 1.2Naming
    
• 2One-third octave bands
  • 2.1Base 2 calculation
  • 2.2Base 10 calculation
  • 2.3Naming
    
• 3See also
• 4References
  

Octave Bands[edit]Calculation[edit]%% Calculate Octave Bands in Matlabfcentre = 10^3 * (2 .^ [-6:4])fd = 2^(1/2);fupper = fcentre * fdflower = fcentre / fd
Naming[edit]

Band Number	Nominal Frequency[1]	Calculated Frequency	A-Weighting Adjustment
-1	16 Hz	15.625 Hz
0	31.5 Hz	31.250 Hz	-39.4 dB
1	63 Hz	62.500 Hz	-26.2 dB
2	125 Hz	125.000 Hz	-16.1 dB
3	250 Hz	250.000 Hz	-8.6 dB
4	500 Hz	500.000 Hz	-3.2 dB
5	1k Hz	1000.000 Hz	0 dB
6	2k Hz	2000.000 Hz	1.2 dB
7	4k Hz	4000.000 Hz	1 dB
8	8k Hz	8000.000 Hz	-1.1 dB
9	16k Hz	16000.000 Hz	-6.6 dB

One-third octave bands[edit]Base 2 calculation[edit]%% Calculate Third Octave Bands (base 2) in Matlabfcentre  = 10^3 * (2 .^ ([-18:13]/3))fd = 2^(1/6);fupper = fcentre * fdflower = fcentre / fd
Base 10 calculation[edit]%% Calculate Third Octave Bands (base 10) in Matlabfcentre = 10.^(0.1.*[12:43])fd = 10^0.05;fupper = fcentre * fdflower = fcentre / fd
Naming[edit]

Band Number	Nominal Frequency	Base-2 Calculated Frequency	Base-10 Calculated Frequency
1	16 Hz	15.625 Hz	15.849 Hz
2	20 Hz	19.686 Hz	19.953 Hz
3	25 Hz	24.803 Hz	25.119 Hz
4	31.5 Hz	31.250 Hz	31.623 Hz
5	40 Hz	39.373 Hz	39.811 Hz
6	50 Hz	49.606 Hz	50.119 Hz
7	63 Hz	62.500 Hz	63.096 Hz
8	80 Hz	78.745 Hz	79.433 Hz
9	100 Hz	99.213 Hz	100 Hz
10	125 Hz	125.000 Hz	125.89 Hz
11	160 Hz	157.490 Hz	158.49 Hz
12	200 Hz	198.425 Hz	199.53 Hz
13	250 Hz	250.000 Hz	251.19 Hz
14	315 Hz	314.980 Hz	316.23 Hz
15	400 Hz	396.850 Hz	398.11 Hz
16	500 Hz	500.000 Hz	501.19 Hz
17	630 Hz	629.961 Hz	630.96 Hz
18	800 Hz	793.701 Hz	794.43 Hz
19	1 kHz	1000.000 Hz	1000 Hz
20	1.25 kHz	1259.921 Hz	1258.9 Hz
21	1.6 kHz	1587.401 Hz	1584.9 Hz
22	2 kHz	2000.000 Hz	1995.3 Hz
23	2.5 kHz	2519.842 Hz	2511.9 Hz
24	3.150 kHz	3174.802 Hz	3162.3 Hz
25	4 kHz	4000.000 Hz	3981.1 Hz
26	5 kHz	5039.684 Hz	5011.9 Hz
27	6.3 kHz	6349.604 Hz	6309.6 Hz
28	8 kHz	8000.000 Hz	7944.3 Hz
29	10 kHz	10079.368 Hz	10 kHz
30	12.5 kHz	12699.208 Hz	12.589 kHz
31	16 kHz	16000.000 Hz	15.849 kHz
32	20 kHz	20158.737 Hz	19.953 kHz

See also[edit]

• Octave
• Octave (electronics)
• One-third octave
  

References[edit]

• Jump up^ "ANSI S1.11: Specification for Octave, Half-Octave, and Third Octave Band Filter Sets" (PDF). Retrieved 7 March 2018.