[quote name='Paul S' timestamp='1457089802' post='2995165']
I don't know much abut desks but isn't there usually always a line out for monitors? That is the feed we use, balanced lead connecting this to the transmitter. It has a different mix to FOH.
[/quote]
Not always. For analogue - Generally on small analogue desks, there will be one or two. On medium desks, there are typically three or four. On large format desks there are typically 6 to 10 (but we are talking large touring desks here). In touring situations, it's not uncommon to split the XLRs at the stage and have a front of house and a dedicated monitor desk to do the IEM/wedge mixing.
In digital world, even the smallest desks tend to have a large aux count than their analogue equivalents.
Remember, you'll need two auxes for a stereo IEM mix... so thinking that your desk with 6 auxes is plenty... well, it depends upon what you need. Thats a maximum of 3 stereo mixes, or 6 mono mixes, with a mixture of stereo and monitor mixes in-between those two boundaries.
In the digital world though, there are more options... like the Behringer P16 or A&H ME1 - which remove the reliance on dedicate aux busses.