Yes, awesome article.
Most problems I've read about/experienced with folks moving to IEM's are caused by mono wireless units coupled with single-driver buds.
For bass, drums or geetar, that's [generally] a recipe for failure.
I've run mono (due to resource limitations) for most of my secular IEM use - tho have recently moved to stereo - and mostly stereo for church (Aviom, Behringer) over the last 5+ yrs.
What I want in my mix depends on whether I'm playing bass or guitar and singing or not.
- When singing, I want lead vox prevalent-center, with my vox blended center also (for the effect), with other vocals center but "behind" mine. I want to hear them, but not be loud enough to throw me off when multi-part harmonies are happening.
- For bass, I want LOTS of bass (centered), I also want kick + snare center (sometimes slightly R/L of center) and guitar/acoustic's panned L or R depending on their stage position. Same with keys or other instruments.
I DO NOT put toms, cymbals in the mix, but may want "more cowbell" if being used!
- For guitar much the same but guitar centered (vs bass blended with drums) with the other instruments panned/leveled as with bass.
It took me some level of experimentation (and time) to arrive at these settings while figuring out that I did NOT need a CD mix in my ears.
Obviously, YMMV.. but I've found it easier to pan instrument physically located on my left to the left and pan instruments (not already centered) that are on the right, to the right. It fits the physical stage and helps locate them when there are multiples playing.
Sometimes I play with multiple electric and acoustic guitars as well as keys and vocalists at church. I find the lead for each and ignore the others (not in the mix if I can do that). I'm not listening to a CD, I'm looking to hear enough in my mix to allow me to do my job the best I can - while keeping the volumes low and protecting my hearing.
PS: Good quality, custom-fit, multi-driver IEM's are the way to go!!!
Not cheap, but well worth the price of your hearing.