We have started simple and cheap and upgraded a few times over the past 6 yrs. to get the ultimate system. It cost us more $ to do it wrong and figure out what we needed than to just buy the correct gear right away. if you want good quality mixes, it costs money, but improves your performance potential exponentially.
We started with just in-ear units from the (mono) aux of the house. = sloppy and dangerous, someone else has control and most club house engineers will turn a knob too far and possibly blow your ears!
Next was Crest XRM = able to do 12 STEREO mixes and has a splitter built in to it....Stereo panning (between 2 aux's) clears up your mix considerably and allows you to place the players where you want, which makes each individual MUCH easier to hear. This was a breakthrough for us. It's mostly knobs which are more consistent than faders, it is rackmountable, so if you put it in one the combo mixer racks, you can house your whole rig in one rack and roll it in pre-connected. This is an easy setup and works as a front of house mixer in a pinch as well. However, there are no built in effects.
Next we went to the Mackie TT24 with a splitter. This step took us into digital console land, which allows you to recall ear mixes (and Main mixes) of certain venues, and most importantly add effects. It is very user friendly and can call up just about anything with 1-2 buttons. It has built-in recallable compression, delay, verbs, eq, etc. PER CHANNEL. which means if I want more verb on my voice than the lead singers in MY MIX, I can w/o affecting the singers mix. Effects are important in an ear mix because the ear buds block out most of the stage and mains sound giving you a really dry isolated sound. There's no air or space in there...so you have to create it with either a verb unit, or an onstage open mic (which changes sound with every room and I don't recommend it except for hearing the crowd noise). Compression keeps your vocals (and others vocals) steady in your mix. Individual compression caters to each singers style. Initially this set up takes time and patience, but once set up, it cuts your soundcheck in half because it is very consistent. There are still a few tweaks for every different room, but nothing major. This board has 8 mono aux or 4 stereo aux and capable of 4 individual effects. This is the entry level digital console...and the effects are not top notch, but got us through a few years of gigs b4 it gave us some glitches (solved by firmware updates and resets).
We now have a system that's probably out of your budget, but its a digidesgn Venue 48 with Sennheiser 300 IEM systems and a multipin snake box with antenna fins, etc....total cost was something stupid like $40,000? even with endorsements. The quality really is stunning, and there's never drop out or audible channel changes, etc. its just flawless and uses all pro-tools plug-ins.
Yamaha makes a relatively affordable digital board called the LS9. Same concept as the TT24....but better quality.
Whatever ears units you use, I would recommend using a system where the body packs use AA batteries. They have a longer life than the 9V systems. If you buy used, make sure your units do not use the BANNED FREQUENCY RANGE! They're starting to crack down and the fines are outrageous. If you go Shure, don't go less than the 400 model. Most Sennheiser's are good quality. There's a cheap foreign company called Mipro and their stuff is OK for the price.
To go the extra mile, I would recommend tossing the buds that come with the IEM in your gym bag, and getting molded ear buds. There are companies out there that will do cost effective quality jobs. Here's one out of Nashville,
http://www.fidelitycustomearphones.net/ Almost all companies make single driver, dual driver and some make triple driver buds. my understanding is that the triple drivers are NOT 3-way crossed over. They are 2 low drivers and one high freq driver. The dual drivers are good for Drums and Bass players, the single drivers are just fine for singers and guitar players. The tighter the seal on your buds, the more low end you will hear. If you as a bassist sing, you might have trouble with your buds loosing their seal as your ear shape changes as you move your jaw.
Careful not to get too greedy with your volume, as it is very easy to damage your hearing, making the whole point of getting IEM's null and void. Start at the lowest volume possible, and use any stage noise to your advantage. I could get into a psychology discussion on how they change the vibe of the gig, but that's a whole different thread! Good Luck!
