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…
pressure, here: air pressure.
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.
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.
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.
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.
voltage in relation to a reference voltage. The reference voltage is 1 V. 6 dBV would then be ~2 V.
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.
Min and max sound pressure level emitted by this sound source, measured at a distance of m.
Distance to sound:
Reference Level @0dBFS:
Input gain control:
Input level for 100 dB SPL output in 1 m distance: