This calculator focuses on the noise that appears in the audio signal chain. The various noises sum up to a resulting noise in the final audio. Depending on the situation some noises have almost no influence on the result. For instance in most cases the preamp noise does not increase the noise sum, as the room noise and microphone noise is much higher.
All dB values should refer to the A-weighted value.
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Show explanation of Pa, V, dB, dBu, dBV, dB FS…
Pa (Pascal)
pressure, here: air pressure.
V (Volt)
electric current.
plain number
digitally encoded audio signals have no unit. Most commonly the oscillation of the wave between its downs and ups is described by integral numbers from -128 to 127 (requires 8 bit), -32768 to 32767 (16 bit), -8388608 to 8388607 (24 bit) or -1.0 to 1.0 (floating point, requires usually 32 bit or 64 bit). Usually audio software calculates with floating point values internally. This tool shows the floating point values when ”Show SI units“ is ticked.
dB (decibel)
a relationship between two values or signals: a difference of 6 dB between two signals means, that one signal is roughly twice as strong as the other; 12 dB means that one signal is round about four times stronger. Adding 18 dB to a signal means actually multiplying it by 8. Using decibels is very practical when working with large ranges of numbers. 0-100 dB for example can describe values from 0.01 to 1000.
dB SPL
sound pressure level in relation to a reference level. The reference level is 0.02 mPa, which is considered as the lowest sound pressure that human ears can hear. 6 dB SPL would then be ~0.04 mPa.
dBu
voltage in relation to a reference voltage. The reference voltage is 0.7746 V. 6 dBu would then be 1.5455 V. -6 dBu are 0.388 V.
dBV
voltage in relation to a reference voltage. The reference voltage is 1 V. 6 dBV would then be ~2 V.
dB FS
amplitude of a digital signal in relation to a reference value. The reference value is 127, 32767, 8388607 (these are the maximum values of 8, 16, 24 bit audio) or 1.0, depending on the used bit width of the digital audio. For audio hardware that processes 8, 16 or 24 bit digital audio only, the dB FS value can only be negative. An amplitude of zero is expressed with -∞ dB FS.
Shows
Enjoy some shows that explain the components of this app and discuss common topics. Some are especially dedicated to my Patreon-followers.
Sound Source
Min and max sound pressure level emitted by this sound source, measured at a distance of m.Sound pressure level emitted by this sound source
min:
dB SPL
max:
dB SPL
Distance to sound:
m
Room noise:
dB SPL
Sound too loud for the microphone. Increase the distance.
Microphone
Pattern / Angle / Distance fact.:
Sensitivity:
mV/Pa
Impedance:
Ω
Eqv. Noise:
dB SPL
max. SPL:
dB SPL
Preset :
Attenuator (PAD)
Attenuation
Input signal too high. Please lower the preamp gain or increase the mic distance or engage a pad to the mic.
Preamp
max. Input:
Noise (EIN):
Gain:
Preset :
Signal is clipping. Please lower the preamp gain.
Analog-Digital-Converter
Reference Level:
max dB FS:
Gain:
Dynamic Range:
Resolution:
Preset :
Noise reduction
Fader
dB SPL
Signal is clipping. Please lower the fader.
Digital-Analog-Converter
Dynamic Range:
dB
Reference Level @0dBFS:
dBu
Preset :
Active Monitor
Input gain control:
dBu
Input level for 100 dB SPL output in 1 m distance:
dBu
Noise in 1 m distance:
dB SPL
Analogue volume control
Preset :
Distance to ear:
m
Noise in the listening room:
dB SPL
Ear
Measures after Noise reduction, as a function of the preamp gain.
