Decibel dB calculation amplification gain and damping loss - sengpielaudio Checker
 
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Calculation: amplification (gain) and damping (loss)
as
level in decibels or dB

Enter two values and press the right calculate bar in the line of the missing answer

Input: voltage power        
           
input   value 1    
output   value 2    
level change   dB        

In analog audio engineering we deal only with 'voltage' amplification (gain) and damping (loss).
gain and loss - sengpielaudio
V2 > V1 means amplification. The dB value is positive.
V2 < V1 means damping. The dB value is negative.
V2 / V1 means the ratio. The amplification or the damping in dB is:
L = 20 × log (voltage ratio V2 / V1)         V1 is the reference.

 3 dB ≡  1.414 fold the voltage    (−3) dB ≡  damping to the value 0.707
 6 dB ≡          2 fold the voltage    (−6) dB ≡  damping to the value 0.5
10 dB ≡  3.162 fold the voltage    (−10) dB ≡  damping to the value 0.316
20 dB ≡       10 fold the voltage     (−20) dB ≡  damping to the value 0.1

Using voltage we get: Level in dB: L = 20 × log (voltage ratio)

  +6 dB = twofold the voltage
+12 dB = fourfold the voltage
+20 dB = tenfold the voltage
+40 dB = hundredfold the voltage

Not often one is interested in power, if we consider audio engineering.
Do not ask what the power amplification is.
Leave that to the telephone company.

Using power we get: Level in dB: L = 10 × log (power ratio)

   +3 dB = twofold the power
   +6 dB = fourfold the power
 +10 dB = tenfold the power
 +20 dB = hundredfold the power

If you search for the amplification factor, given the dB value,
then go to the program dB calculation

Aha!
 
At the cut-off frequency fc the dropped voltage is always fallen to the value of
1/√2 and the voltage level L is damped to 20 × log (1/√2) = (−)3,0103 dB.
 

Enter a value in the left or right box, then press the TAB bar or make
a mouse click at an empty space at the side, to get the solution.
The calculator works in both directions of the sign.

Voltage V
volts
 ↔  Voltage level LU:
dBV
V = V_0 \cdot 10^\frac{L_V}{20} \ \mbox{volts}   L_V = 20\, \log_{10}\left(\frac{V}{V_0}\right) \ \mbox{dBV}
Reference voltage V0 = 1 Volt ≡ 0 dBV
Voltage V (Audio): 
volts
 ↔  Voltage level LU (Audio) :
dBu
V = V_0 \cdot 10^\frac{L_V}{20} \ \mbox{volts}   L_V = 20\, \log_{10}\left(\frac{V}{V_0}\right) \ \mbox{dBu}
Reference voltage V0 = 0.7746 Volt ≡ 0 dBu

The voltage is always given as RMS value - but not the electric power.

Electric Power P
watts
 ↔  Electric Power level LP
dB
Formula1   Formula2
Reference electric power P0 = 1 W ≡ 0 dB

There is also the reference power P0 = 1 milliwatt or 0,001 watt ≡ 0 dBm

Electric power (telephone) P:
watts
 ↔  Electric Power level (phone) LP
dBm
Start   Start
Reference power P0 = 1 milliwatt (mW) = 0.001 W ≡ 0 dBm

Amplification and Damping

gain factor v = V2/V1:
for field quantities, e.g. voltage

 ↔  amplification level L:
voltage level
dB
Formula Factor   Formula Amplification
Voltage gain v = 1 ≡ 0 dB

In audio technique the following "power or energy amplification " is rather unusual.

gain factor v = P2/P1:
for energy quantities, e.g. power

 ↔  amplification level  L:
power level
dB
Formula1   Formula2
Power gain v = 1 ≡ 0 dB
  Voltage/Pressure 
  amplification factor 
  1  
 
 1.414 
= √2
  2  
 
 3.16
= √10
  4  
 
 10 
 
 20 
 
 40 
 
 100 
 
 1000 
 
  Increasing of x dB  0   3   6   10   12   20   26   32   40   60 

  Power/Intensity  
  amplification factor 
  1  
 
 1.414 
= √2
  2  
 
 3.16
= √10
  4  
 
 10 
 
 20 
 
 40 
 
 100 
 
 1000 
 
  Increasing of y dB  0   1.5   3   5   6   10   13   16   20   30 

Level in psycho acoustics as subjectivly perceived loudness (volume)

 
The word "power amplifier" is a misnomer. Power is not really something
that can be "amplified". Voltage and current can be amplified. The term
"power amplifier" although technically incorrect has become understood
to mean an amplifier that is intended to drive a load such as a loudspeaker.

 

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