by Wonks » Tue Sep 11, 2018 9:20 am
Assuming that you just have vocal and guitar, then you can use the control room outputs to send a copy of the main mix to your IEM transmitter. This should be better than using the headphone output. Of course you get the FOH mix complete with any reverb from the FX unit you've added.
Anything more complex and you'll need a better mixer. You may fine with IEMs that you can't hear the audience, so you'll need a room mic. You won't want the room mic going to the FOH speakers, so you'll definitely need a mixer with at least one proper aux output for that.
If you are also using backing tracks, then you'll almost certainly want a better mixer as you'll probably want far less backing in your IEM mix than for the FOH mix.