Live Sound for Singers – Gain is Not Volume

Craig Fraser introduces the relationship between the mic’s signal and the mixing desk in this series on the basics of live sound.

150x150-craigfraserCraig Fraser is a Product Specialist at TC-Helicon Vocal Technologies. He is involved in product development, technical writing, customer service and videography. Prior to this, he was Director of Operations at Marble Wave Sound Design.

  • Thank you for clearly explaining this important piece of information. I get it!

  • Wakakanada

    Thanks for this valuable information on something I have never understood before. I look forward to the next installment!

  • rob

    I appreciate that info Craig.I sometimes forget and go backwards out of habit.Did you mention that most mixers have a led indicator on each channel fader to check that gain level before fader volume goes up. What about channel faders in relation to master volume, should master volume be set next ?And setting levels in relation to one another? For instance, sound checking everyones mike one by one and vocalists singing their loudest note to get the right level and leaving some room for everything that’s being amplified?.Acoustic Guitars miked electric guitars,drums,etc.? Also eq first for tone then volume right?Sorry had to much coffee. Anyway food for thought.I’m finding that less volume especially in boomy rooms is better.

  • Stewart

    Excellent video. One thing to note (and possibly one for an advanced video) is that relationship to Gain and Output volume. Craig mentions the instrument (mic) input gain and how the board / desk “gain stages” (there’s those words). Then there’s the output to Amplifer and speakers. When an engineer talks about increase in gain – there’s a relationship to the output which people don’t understand (There’s also a relationship to Voltage Sound Pressure). (A 3dB gain increase only increases the output “loudness” by a factor of 1.23 (some may call it loudness – but it’s the relationship from the amps input to it’s output). A 6dB gain has that output “volumentric loudless” by a factor of 1.52 . A 10dB increase has its output at 2 times (i.e. double). Gain staging is important (as Craig shows) that if any artifacts (noise .. etc) exist in one of the gain stages – increasing further chained opamps will increase that artifacts perceived volume. So Gain staging is important.