db dbm conversion dBu to volts dBV and volts - sengpielaudio Checker
dB dBu dBV dBm level volts volt calculator conversion conversions convert calculate compute calculations calculation modulation online calculator unloaded attenuation calculation voltage converter power ratio ratios sound studio level maximum ratio ratios reference 1 volt power milliwatt decibels decibel decibels domestic loaded quantity quantities unloaded dBA reference voltage level loss gain volts impedance pressure microphone microphones receiver ratio reference Sengpiel Berlin sengpielaudio
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Voltage V and voltage level LV
dB  conversion (decibel) •
dBuvolts (rms), dBV → volts (rms)
volts (rms) → dBu and dBV

 Lu    dBu  |    LV     dBV  |  V  volts (RMS) 
   |     |   
LV  dBV  |  Lu dBu  |    Lu     dBu
V volts (RMS)   |  V volts (RMS)   |  LV  dBV
       |         |       
  volts (p-p)  |    volts (p-p)  |     

Fill out a gray box above and click on the respective 'calculate' bar under it.
The reference voltage for dBu is 0.775 volt (0.77459667 V) and for dBV it is exactly 1.0 volt.

The origin of the index of dBu comes from "u = unloaded" and of dBV is from "V = 1 volt". Some say:
The "u" in dBu implies that the load impedance is un specified, un terminated, and is likely to be high.


What is dBu? A logarithmic voltage ratio with a reference voltage of V0 = 0.7746 volt ≡ 0 dBu
What is dBV? A logarithmic voltage ratio with a reference voltage of V0 = 1.0000 volt ≡ 0 dBV
The home recording level of −10 dBV means 0.3162 volts, that is −7.78 dBu
Level: +4 is for pro audio, and −10 is for consumer audio.

If you need dBm with "m = 1 milliwatt", go to: Conversion: Voltage V to dB, dBu, dBV, and dBm

Level   Formula volt to level        Voltage   Formula level to volt

There is really no fixed standard like e.g. 20 dBFS = 0 dBVU = +4 dBu.
We got no such reference. dBFS is a digital level and dBVU is an analog level.
Digital and analog are two totally different worlds.


Advice: Watch only your digital meters and go up to 0 dBFS, but never go
over this mark. We need no "headroom" in the digital domain, like we use
it in the analog domain.


Never take the following funny guessing game for granted:
European & UK calibration for Post & Film is −18 dBFS = 0 VU
BBC spec: −18 dBFS = PPM 4 = 0 dBu
American Post: −20 dBFS = 0 VU = +4 dBu
Orchestral −18 dBFS = 0 VU = +4 dBu
Rock and / or Radio −16, or −14, or −12 dBFS = 0 VU = +4 dBu
Digi 002 is only capable of −14 dBFS.
German ARD & studio PPM +6 dBu = −10 (−9) dBFS. +16 (+15)dBu = 0 dBFS. No VU.

Room Modes - sengpielaudio

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 (audio):
volts
 ↔  Voltage level LV:
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)
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)
Electric power P:
watts
 ↔  Electric power level LP:
dB
Formi   Formula
Reference electric power P0 = 1 W (0 dB)

Conversion of voltage or power ratios to decibels dB - table and chart
Table of Sound Pressure Levels and Corresponding Sound Pressure and Sound Intensity

RMS voltage, peak voltage and peak-to-peak voltage

The parameters of the mains or "power" sine wave form are summarized in the table below:

Average voltage RMS voltage (VRMS) Peak voltage (Vp) Peak-to-peak voltage (Vp-p)
0 volts 117 volts = VRMS 165 volts = √2×VRMS 330 volts = 2×√2×VRMS
0 volts 230 volts = VRMS 325 volts = √2×VRMS 650 volts = 2×√2×VRMS
Enter one known voltage:
VRMS = volts
Vpeak = volts
Vp-p   = volts
Do not reenter an answer!
 
Voltage RMS Peak - sengpielaudio
  VRMS Vp Vp-p
RMS value     VRMS = 0.7071 × Vp 0.3535 × Vp-p

Peak value     Vp      =

1.414 × VRMS 0.5000 × Vp-p
Peak to peak Vp-p  = 2.828 × VRMS 2.000 × Vp

The crest factor means the ratio of the peak voltage to the RMS voltage.

If you need to calculate an attenuator (attenuation calculation) you calculate a voltage divider.

International levels

Level

Level L in dB Voltage (RMS)

International studio level - USA

  +4 dBu 1.228 V
European studio level - ARD broadcast level   +6 dBu 1.55 V
Domestic recording (Consumer units) −10 dBV 0.3162 V = −7.78 dBu
Sound pressure level (auditory threshold)      0 dB 2×10−5 Pa ≡ 0 dBSPL

International reference values

Physical unit Reference value Level unit Note
Voltage V0 = 0.775 V ≡ 0 dBu Audio technique, no impedance reference!
Voltage V0 = 1 V ≡ 0 dBV Audio technique, USA
Voltage V0 = 1×10−6 V   HF receiver and amplifier technique
Voltage V0 = 0.224 V   HF technique - Reference 1 mW at R = 50 Ω
Voltage V = 1.228 V   Studio level +4 dBu, USA - Reference 0.7746 V
Voltage V = 1.55 V   Studio level +6 dBu, ARD - Reference 0.7746 V
Voltage V = 0.3162 V   Home recording level -10 dBV = 7.78 dBu - Reference 0.7746 V
Sound pressure p0 = 2×10−5 Pa ≡ 0 dB Sound Pressure Level SPL, auditory threshold (Sound field quantity)
Sound particle velocity v0 = 5×10−8 m/s ≡ 0 dB  
Sound intensity I0 = 1×10−12 W/m2 ≡ 0 dB Threshold of pain at 1 W/m2 (Sound energy quantity)
Power P0 = 1 W ≡ 0 dBW  
Power P0 = 1 mW ≡ 0 dBm at R = 600 Ω (telephones) or 50 Ω (antennas)
Electric field strength E0 = 1×10−6 V/m    

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

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