hi,
live vocals:
1. if the monitormix is done from foh i split the mic signal into to channels. i do this for nearly every incomming vocal mic, if the channels/cables allow it.
2. the first of these channels i use for the front, the second for monitor. i useually set it up like this:
voc right, voc center, voc left, voc drummer(or what ever), voc right monitor, voc center monitor, voc left monitor, voc drummer monitor. so that i have all the monitor channels seperate. the monitorchannelfaders are all at 0 and not routed to master oder groups. the eq are hopefully pre-aux-ways.
3. the front channel: i eq less than in studio, but if theres a hpf i pull it up until the singers voice starts to lose to much bottom. i use compression, but in the studio i use like -10 to -20db gain reduction, if its a good singer and a good pa system you dont need anycompression live! but amounts of -5db gr are common for livemixing. with heavy compression you can easyly run into problems with feedback. this is where the monitor spilt thing comes into play.
4. the monitor mix: because there is no compression apllied to the monitor split channels, you dont run into feedback that fast, as with compression on the channel. if you have troubles with feedback you may have 31'bandeq's ore you can use like -3db amounts on the channels eq (if it is a eq pre aux desk).
5. good live compressors are dbx166xl, drawmer, bss, klark. theres a model by bss with deesser, i really dig this one. the distressor is also a very good one, but its rare in live situations in germany... if there are shitty comps, i dont use them.
6. you can also use a bus to compress all vocals with one/two compressors, but i think thats not sounding good. but this is also a way to have a less feedback possibillity, because theres no compression on the monitorways this way.
7. i like the tc m.one for tapdelay, and the spx 990 for plate or reverb on volcas.
8. compression, normally i use amounts of -5 to -10db gr with 1:2 to 1:4 ratio. if its a singer that is very low and very high in volume from time to time, and the system allows it (...feedback) i use ratio 1:6 to 1:8 and grainreductions up to -30db... witch is fuckin heavy...
9. i try to eq the voice not to much, so that the singer isnt losing his charatceristics, its more a cutting of boomy and harshy frequencies
the feedback thing is often a problem in tinny venues, but with a little time and some 31band eqs it is to handle.