This exactly. It goes back to the board tape argument I got into early in the thread. I regularly mix a 1k seat hall and if the stage wedges are loud it completely changes the entire FOH mix. Likewise there is a 4 second rt60 in that room, if I throw on phones everything sounds dry as a bone and the elements sound disconnected but it's irrelevant b/c everyone is hearing it with room resonance and a ton of natural reverb. That's just a single example but every live guy has a similar story about 90% of the places they mix.
Headphones are for checking lines, cueing, looking for issues and generally troubleshooting. You can't mix on them live.
Huge+1 to the last line.
I don't check for issues on them as the issues are usually due to the room, But checking lines in setup and double checking if something has gone down is probably all I use headphones for. (This is your only hope when checking if a line has gone down during a 'big band' or orchestra, no randomly just walking on stage)
The only place I ever got into a bit of headphone mixing was when I worked for an amazing perfect treated room built for orchestra's and choirs requiring next to no sound reinforcement. Except for certain large performances and having to mic harps, pianos, solo mics for the occasional trumpet, clarinet, etc solo. My mix spot was at the back of the Theater/higher than the Small P.A so I learned to mix decently from it but the constant fear of deafening some one in the front row(seated about 3 meters from the P.a) by putting too much piano or too solo mic into the boxes taught me to depend on headphones just a little. Usually by the time the mics traveled to me at the back it sounded balanced and wonderful but obviously 30 people up the front were dying and the elderly would complain so I understand the use of headphones especially when I wasn't allowed to leave my booth to sit up front or walk around for 5. After a while I barely needed them because I started to know when something was too loud for the front crowd though.
Monitor guys should be the ONLY people allowed to wear headphones/in ears especially if they don't have a listen wedge next to them.If they are mixing in ears for someone, listen to the mix with in ears! I dislike guys who just check monitors in headphones if they have to mix FOH and Monitors. I am not afraid to walk on stage and listen to a monitor wedge if someone is having trouble. Dudes that just think "well I have put everything up so It can't be my fault" annoy me. Go and listen to exactly what the artist is hearing! Your headphones don't involve bleed or if the box is shitty itself/some other error.
(P.s I hate monitors, if only I got to mix on Big P.A's without having to deal with monitors more often)
Kick and bass should be your main low end. Too many guys let the guitar have to much low end which I feel clouds things up and gives them no separation. pull some of that shit IMO. I don't like perfectly dead toms either and enjoy some of teh b00m but this is where gates come into play,especially when running monitors from FOH.
TBH, Most FOH guys suck around here. They make sure level is coming in the channel. Turn things up...a little and there ya go. mix done. I played a decent size metal fest with Psycroptic, Blood Duster, Extortion etc(possibly thought someone decent might be mixing the show instead of just being a P.a babysitter, I was wrong) and apparently no one heard any kick drum, I had no guitar in monitors, vocals were barely there and average mixes continued for most of the day unless a band brought their own engineer. possibly heard the guy get off his ass and mix ...one good band.
end rant/ tmi?