Allow me to offer a different perspective on this. You could set the gains for the pre-amps as hot as possible to keep the analog pre-amp warm so you are getting the most out of it. Then you would set the desk to use the trim in order to set your faders at unity gain. In the analog world, the gain and trim knobs are pretty much the same thing depending on the console you have, but digital has allowed the ability to run the pre-amps hot, and dial back with digital trim.

Just a thought on the subject.

Thanks,
Scott Morgan

Many amateurs tend to run pre-amp gains too hot and under estimate the headroom they need for the energy of a live gig once the band gets rolling…. We consult at many churches and see way to many red lights during the “service” that may not have been seen in practice.

With modern mixers and the low noise that quality systems have, make sure “hot” does not distort (mic pre-amp) or clip (digital) when the snare is slammed by the drummer or the vocalists “screams” or the bass player starts slapping the strings…..[]

Bob

Here is an easy to use gain structure for most consoles digital or analog. Works best with a split mix for the monitors. Most of the touring guys I work with use a simple setup to ensure enough headroom for the pres and the channel strip as a whole, leaving room for EQ boost and dynamics make up gain. Start with the input trim fully attenuated, channel fader to unity, main fader to unity, then turn up the input gain until the desired SPL foer the source is reached. When you have a group of like instruments say drums do this one channel at a time setting each channels volume in the mix with the input gain, once done with the group, eq them all, set your dynamics and “re-mix” them with the input gains. This leaves all you channel faders at unity where they are the most responsive within the audio taper of the fader allowing you to mix using very small fader movements. This method also matches the output of the source to the system better allowing for less bleed and leaving the mic focused on it’s source instead of entire ensemble or band… Give it a try! In analog world this method will give you an excellent signal to noise ratio as an added benefit!

BKool

Chris93, while I agree with the electrical engineering theory of what you posted. Try this experiment, take a mic in a fairly live room, open the gain all the way, record it, then halve the gain, record it, then halve it again, record it. You should find wide open you will hear the whole room, at each halving of gain your “world” will shrink making sources father away fainter less prominent in the recorded “mix” making the mic “sound” intimate and selective to the source to the source.

To all running a pre-amp hot is wonderful if you are looking for a harmonically rich content, many pres can even be clipped slightly red lights and all and you will not hear the distortion, only a warming, this is very true when the slew rate of the pre exceeds the psycho-acoustics of the human ear and allows it to recover before your ear can detect the hard part of the clip. This was an 70/80’s trick to massive sounding rack/floor toms. I saw an interesting demo of this way back maybe 30 years ago when chipsets got faster and have used it to good advantage many times! That said harmonically rich is not always the proper mode for all music and instruments

Digital clip is another matter, and really not to be induced, if you like your job at FOH…

BKool