Reply To: Live Sound Engineering Tutor?

[dpdan]

excellent response Dick R,
so many people have screwed up EQ settings on stage monitors,
I suggest setting the EQ on all the stage monitors to completely flat,
then try setting levels,

Most stage monitor speakers sound halfway decent without a major amount of EQ. but not all of them. 🙂

Always start with your monitors and microphones’ EQ set flat. It is the best place to start,
if you have the time during a “sound check” and you have some feedback, it is most likely a single pitch that is just too efficient in the system. The objective in this case is to find that exact frequency, then cut that frequency with a very narrow bandwidth. I always use the saying.. pardon me but.. “poop or get off the pot” cutting a little tiny bit isn’t going to fix it, slam that frequency all the way down as low as it will go, if the frequency that you are cutting is correct, then that feedback pitch will go away, and you may need to leave it completely cut.
How do we find the offending frequency???

With a QU mixer, you can use the very convenient RTA (real time analyzer) but if you don’t have that option, like using a different mixer, use the following method…
Warn the people in the room to watch their ears because it’s gonna get loud and ugly.

Make sure ALL the other monitor mixes are completely muted. Raise the level of the monitor master to make it just start to feedback “just barely hovering” then raise each one of the 31 bands “on the graphic EQ one at a time” slowly until suddenly the feedback goes nuts. Even if the feedback goes nuts, it doesn’t mean we found the bad frequency,,,it might actually be the next band that is the culprit. So be methodical about it, start with lower frequncies (usually above 100 hertz,) and go higher…. NOW, we know what the exact offending frequency is. So, slam that band all the way down. I suggest after lowering the first most obnoxious frequency that you raise the volume of that monitor again even more now, until it feeds back again, but this time it will be a different frequency, again, find the frequency and notch it out. I suggest doing this no more than three times, any more than this the monitor is going to sound horrible.

Do this same process for all the other monitor mixes, of course you will need to have mics turned up in those monitor mixes so that the monitor gets to feedback with the mics it is going to have to reproduce.

Even after this has been done, feedback can still occur and I suggest assigning all the monitor mix masters to a singe DCA. That way you can have a single master fader (only on the custom layer) for ALL MONITORS.

Some other very basic, but very good things to remember,,, if something sounds shrill and hurts your ears it is between 2.5 khz. and 4Khz. Usually 3K. Sounds that can really get on your nerves in this area are some female vocals, violin, trumpets, guitars and guitar amps especially.

That’s a good start 🙂