Where do I set the gain slider on the DL as a starting point?
most people will suggest Zero dB, otherwise referred to as (unity gain)
It is the best place to start,
Here are a few tips from blabber Dan
if you are mixing sound and you feel like you need to raise the master fader because your speaker system is not loud enough, one of two things is the culprit.
A. it is a heavy metal band, and you have two small speakers on sticks outside, trying to project sound to three thousand people, or
B. most, if not all of your inputs' Gain slider (red) are set way too low.... even with all the input faders set pretty high, the audio from all those channels going into the L/R fader is not enough and would cause you to have to raise it even higher than zero dB. in order to provide enough output voltage from your DL mixer to your main amplifiers/speakers to their safe capacity.
While I have to admit, I have never actually performed a test for the calibration of the level meters in Master Fader to it's color indication, voltage output, and distortion, I do know this... way more times than I can remember, my lead vocalist's input is set pretty safely, but all too often he hits red and hits it pretty hard and there is no "audible" distortion. My multitrack recording proves during these extreme dynamics that the Mackie's mic preamps have not only great signal to noise ratio, but also silly good headroom. How do I know this? Once the audio files are transferred and playing in Digital Performer, the wave form in the lead vocal track reaches zero dB, (MAX) the maximum volume a digital audio track can contain, and it is super clean. This all sounds like Mackie might have done a good job setting and calibrating these things.... but if I know how some "electrical" engineers are, they choose to calibrate the meters so they lie to us making the pre-amp seem indestructible. Personally, I would prefer that I hear ever-so-slight distortion once the levels go a "smidge" past red. In the old days, analog sound board manufacturers would give us the spec that red indicates a certain percentage of distortion relative to the decibel level produced. This same euphemism terminology is all too common when manufacturers advertise their new powered speaker amplifier "wattage". Even though I like QSC products,,, 2000 watts on the K.2 series ......NOT SO FAST QSC. Mackie, QSC, JBL, EV, and even RCF, fib.
An indication that most of your input levels are set pretty good, is to see the L/R level meters tickling the orange color.... when the fader is set to zero dB.
Always use your ears, trust them before you trust any fader levels or colors on meters. I have seen people who claim to be an "audio engineer" and they set the master fader to unity, then they set all the input faders to unity, then they set the gain for the inputs... OH MY WORD!
leave the mains and subs off, (muted) ask the drummer to play the drums like he will when the band is playing... set the gain for those drums, then the bass, then keys, then guitar, then all the other stuff. Once the levels are set, unmute the mains and subs if they are fed separately, and begin to mix. I always suggest bringing up the vocals first, then once they are at a good level to you, then bring up the other inputs to your desire. I usually tell the band that during this real quick sound check, the monitors will not be on. After a few minutes at most, I wave my hand to tell them to stop,,,, then I set levels for their monitors. I go to each person with a monitor and ask them what would they like to hear in their monitor, if they say "everything" I tell them that they need to keep only the things that would be impossible to hear without a monitor, like their voice, and maybe the other vocalists and maybe a little bit of their guitar or instrument that they are playing. There are many variables, but this is what has worked great for me for many years
