Some live sound engineers think of it as the halfway house between being a runner and an actual live Front of House (FOH) mixing engineer. For me, monitor mixing is great in its own right. There are certain drawbacks to being way out there by yourself mixing at the FOH position while the monitor mixer is in the middle of the party that's going on onstage. What's the party all about, and why is it so much better to be monitoring than mixing?
Back-stage pass with benefits
You are there smack-dab in the middle of it all by the side of the stage. You're working closely with the band, making sure everything goes smoothly. You're the most important person to that band since they all want to be able to hear themselves well. Like a back-stage pass with benefits since you're just as important to the band as any of their members.
Almost a part of the performance
The most rewarding thing about doing monitor mixing is how you are so involved with the performance. Since you are responsible for making the band sound great onstage you are helping them feeling comfortable and therefore giving a better performance. Helping the band hear themselves better so they play better is hugely rewarding.
When you're dealing with 5 members wanting 5 individual mixes from 10 tracks you have a challenge in front of you. Compare that to the FOH engineer that just needs to worry about making that main mix sound great and you could say that the monitor mixing engineer's job is much harder. It's certainly a challenge to mix 5 mixes at a time, and if you are dealing with multiple bands every night it becomes even more complex. So it's definitely more challenging to keep track of things on the monitor side of mixing.
You make the band happy
Working with a group of artists is very entertaining. Being in the middle of the action, making sure everyone sounds great on stage makes the band happy. It's very gratifying to get mutual respect from gifted artists. Make the band happy by being a good monitor mixing engineer and you will gain the respect of the band and a reputation for being good at what you do.
Monitor mixing should not be looked at as a compromise on your way to bagging that FOH gig. It's a great job on its own and has some advantages to it that FOH mixing does not. Being in the middle of things, dealing with the artists and making them happy is all a part of the program when you're backstage fixing their mixes.