A217Name:

Assignment – dB CalculationsDate:

  1. Calculate the decibel difference between 60W and 120W.
  1. Calculate the decibel difference between 100 V and 10V.
  1. How many dBm is a signal with 120 W of power?
  1. What is the dB SPL of a signal that is 450 Pa?
  1. What is the dB SPL of a signal that is 80 Pa? What is the dB difference between 450 Pa

and 80 Pa?

  1. How many dBu is a signal that measures 4.5 volts?
  1. What is the voltage gain in dB of an amp that has 100 watts at its output when its input is 100 mW?
  1. Amplifier A has a voltage gain of 10 (i.e. 0.1V input comes out as 1V), and amplifier B has a voltage gain of 100. If we connect A and B in series, what is the total gain in Decibels (hint: add them like resistances in series)?
  1. A signal with 1-mW of power produces .775 V RMS when connected across a 600-ohm load. A) What is the voltage when connected across a 50-ohm load? B) A 75-ohm load?
  1. Your crown amp has a voltage gain of 1000 and your Yamaha amp has a voltage gain of 10,000. A) What is the dB difference between them? B) If we connect both in series, what is the total gain in Decibels?
  1. A signal measures 1 volt RMS when connected across a 600-ohm load. A) What is the power in watts of this signal? B) What is the current? C) What would the dBm reading of this signal be?

  1. A) What is the standard operating level (in terms of dB) for pro audio gear in the U.S.? B) For consumer gear? C) What is the voltage level of the pro audio standard? D) What should the VU meter reading be for the voltage found in part C? E) What is the voltage level of the consumer standard? F) What is the difference in dB between the two standards? (Show all your work)
  1. What is the voltage equivalent of the signal level -40dBm?
  1. What is the voltage equivalent of the signal level +4dBm?
  1. What is the voltage equivalent of a +6 dBu signal?