Questions & Answers

Main output channel Bus question

0 votes
asked Aug 7 in Studio One 3 by tinman3k (160 points)
General question-

The plugins I place on my main out to monitor levels do not seem to match the levels on individual channels.  I realize this is a sum of all channels, but for my example, I wanted to see how accurate the VU meters are.  Using a tone generator and the VU meter, I solo a track, set the level to -18db and the VU meter correctly reads zero and using a level meter I can see the level is -18db.  When I keep the tone generator going to my master bus, using the same VU meter, the reading is much less than the -18db.  If the master bus is the sum of all of my mixer channels and i have this one on solo, why are the meters not the same?  My mixes were sounding off and I could not figure it out until now; the readings on the master bus are totally inaccurate.  What gives?

1 Answer

+1 vote
answered Aug 8 by PreSonuSupt4 (100,590 points)
selected Aug 8 by tinman3k
Best answer


If you put a tone generator on a channel and look at that level in the Master bus it will reflect two things:

  1.  The post-fader level of the signal.   In order to pass the full level the channel needs to be at unity gain, 0.
  2.  If the channel is mono and panned center it will also be trimmed -3 based on the default pan law of -3.

If you have a tone generator putting out -18 on a mono mixer channel and that channel fader is at unity and it's pan is dead center and the master bus fader is at unity, you should see a level of -21 or so in the master bus meter.  If you pan that channel hard left or right it should read -18.