Calculating weighting filter frequency to dBA and dBC DIN IEC 651 calculator

Sound measuring (Noise measuring)

Weighting filter after DIN EN 61672-1 2003-10 (DIN-IEC 651)
Calculation: Frequency f → dBA und dBC

Notice: Sound level meters measure the sound pressure level in dBSPL.
Sound pressure is a sound field quantity.

The used browser does not support JavaScript.
You will see the program but the function will not work.

At sound level analyzers the display (attack time t_in) is time weighted. There are different settings:

Slow (S):	t_in	=	1000 ms
Fast (F):	t_in	=	125 ms
Pulse (I):	t_in	=	35 ms,	t_out	=	1500 ms

Note - Comparing dBSPL and dBA: There is no conversion formula for
measured dBA values to sound pressure level dBSPL or vice versa.

dBA curve

The A-weighting filter curve is defined from 20 Hz to 20 kHz.

dBA: The decibel A filter is widely used. dBA roughly corresponds to the inverse
of the 30 dBSPL or 40 dBSPL at 1 kHz equal-loudness curve for the human ear.

An A-curve always provides for "nice" values when low frequency noise signals are included.
An A-filter of a measured motorcycle noise must show untrue values. You should know that.

dBC: The decibel C filter is practically linear over several octaves and is
suitable for subjective measurements at higher sound pressure levels.

Notice: The sound pressure p as a sound field quantity
moves the diaphragms of the microphones
and the ear drums of our ears.

And what operates the sound level meters?

Comparing dBA and dBC

Relative Response (dB)	Frequency f in Hz
Relative Response (dB)	31.5	63	125	250	500	1000	2000	4000	8000
dB(A)	−39.5	−26.2	−16.2	−8.7	−3.2	0	1.2	1	−1.1
dB(C)	−3	−0.8	−0.2	0	0	0	−0.2	−0.8	−3

back

Search Engine

home