How can you mix and master audio content for live performances?

In my experience, ensuring that your audio sources have the best possible quality is the most important step to achieve a good mix and master. If you are in charge of the recording, you have to make sure that you are getting clean and stable audio signals in every single track. If you receive previously recorded material, you have to go through its entirety to make sure that the audio recordings are clean, have enough gain, and to identify if there are any phase problems.

I heard this great tidbit from someone online (although I forget who so can't credit them). - Always mix so that if you got hit by a bus, someone with any decent amount of training could take over for you. If the feed getting recorded or getting broadcast is a priority, never do that in addition to either FOH or Monitor engineering. There is a reason mixing for the band and mixing for the audience are different jobs, and that is why you'll almost certainly want to pipe the feed to a broadcast truck or a separate console backstage for broadcast. Oftentimes, the FOH feed will be the closest to what is desired by the talent, and many riders will specify what they want. It's a thing to think about for artist riders, if nothing else.

I believe that every Audio Engineer has a unique organization and mixing process and system. For me, the first step is to organize my tracks, label them, create groups, bus tracks , auxiliar tracks for effects, a Mix Bus, etc. Then, I do a “Volume” fast mix trying to balance all the instruments, vocals and audience tracks using volume faders and panning only, no automation and no effects. Once I’m happy with this first mix, I start by adding compression, eq and effects where needed. When it comes to a live recording I always try to get the most natural sound possible. Having a stereo reference mix from the FOH mixer board is very useful. Also having a stereo field recording of the live source adds great texture to the mix.

If you have never heard of Frequency Masking, I recommend you find a good article about it before you start to add EQ to your tracks.

I agree, however, In my experience I’d suggest to add effects and processing only when needed. Some of the best live recordings I’ve listened to are from the 70s and 80s, just a little bit of eq and compression. Going crazy with processing may change the nature and sound of the live recording.

Don't get fooled by plugins companies always telling you you can't miss this or that plugin. You need to learn as much as you can from the plugins you already own. You can always get more than you believe from what you already have.

Mastering is always a tricky step, it can improve your mix or it can destroy it. I’d suggest several tiny adjustments with specific purposes. Having a reference track is useful for sure. It’s about improving the sound of your mix while delivering the loudness requirements for your master.

If you have to do the mastering of your own recordings -which is a very hard job-, keep checking your reference tracks as much as possible. And don't forget that reference tracks need to be of the highest quality! Either WAV or AIFF.

In the “old” days, there was no offline bouncing/export. You’d have to listen to the entire master during the export process. I believe it’s necessary to listen to your master before delivery in different speakers and sound systems, if it sounds good on a crappy speaker you’ll know you did a good job. Asking for feedback is not always a good idea. Ask feedback from someone you trust.

Never stop learning. Don't you ever believe you've learned everything you needed to know. You'll never will! Always check the sources. There are too many "wise guys" preaching their limited knowledge.