If you're used to performing with a headphone mix in the studio, stepping onstage and realizing that there is no controlled mix to play along with can be very disorienting. It goes without saying that you must be able to hear your bandmates in order to perform with them; being able to hear yourself is of equal importance. Even the most seasoned live players will sound out of time and, possibly, out of key if they can't hear themselves and the rest of the band.
There are myriad sonic gremlins that assault your eardrums at every venue, and the problems get worse the larger the venue, from pitch-shifting delays off of a rear wall to bass-frequency-eating hallways behind the stage. Stage monitoring systems are designed to tame these gremlins, letting you hear your band; yourself; and, in some cases, a clear take of what the audience is hearing.
Two types of stage-monitor systems are in use today, each with its own set of pros and cons: Floor monitors, or wedges, are loudspeakers that sit at a 45-degree angle and point toward the stage; personal monitors are generally a combination of earbuds and a headphone amp. A complete mix of the show is piped to the band's monitors, and in a complex system, each performer receives a custom feed.
Before sending a mix to the band's monitors, the instrument feeds will need to be mixed through a mixing board. For small venues, where the performers can get by hearing the same mix as the audience, almost any mixer with an adequate number of inputs (such as a Mackie 1402-VLZ) will get the job done. Any output from the mixer that duplicates the main stereo outputs (such as the tape out) can be used to feed the monitors. However, you'll need separate level control for this output because the mixer's master fader will be set for the audience mix. If you can't control the level adequately from your monitor amps, you'll need to run the signal through a preamp, such as a small line mixer.
To send individual mixes to select wedges or personal monitors, you'll need a mixer equipped with several aux sends per channel (such as the Mackie Onyx 1640). The main drawback with this system is that the performers won't be hearing the audience mix, though with a good live-sound engineer, this shouldn't be a problem. If the performers are using earbuds and complaining that they can't hear the audience, set up audience mics and incorporate these into the custom mixes. Whichever system you use, make sure to have dependable limiters on your mixer's outputs to protect everybody's eardrums from accidental volume spikes.
ROLL OUT THE WEDGES
Traditional wedges are large, heavy and usually black so that they are not an eyesore onstage, and external power amps are typically employed. A wonderful alternative to traditional wedges are self-powered P.A. speakers, such as Mackie's SRM350 and Behringer's B300. These models feature a unique box design that allows them to tilt back and sit in a wedge orientation. The versatility of being able to use the same set of powered speakers for a coffeehouse gig or as floor monitors in a club setting is ideal for the band on a budget. The speakers also sound great and have discrete level and tone controls.
Feedback is of particular concern when working with floor monitors, because of their proximity to the microphones. This is particularly troublesome when monitoring the audience mix; with discrete mixes via the aux sends, a microphone that's too close to a floor monitor can be pulled out of that monitor's mix. Automatic feedback eliminators, such as Sabine's FBX Feedback Eliminator series, can help eliminate feedback. When feedback happens, these units will automatically find the frequency that's feeding back and dial it out of the mix. Sticking with unidirectional (versus omnidirectional) mics also helps to reduce the chances of feedback by limiting a mic's pickup range. The venerable Shure SM58 is unidirectional (cardioid) and offers good off-axis noise rejection — keep it pointed away from the floor monitors, and all should be good.
IN YOUR EAR
Although a headphone amp is at the core of a personal monitor system, beyond this component, there's little similarity to a studio's headphone distribution amp. Personal monitor systems can be wired or wireless (I recommend wireless for the most flexibility onstage); the headphone amp may feature a mixer for controlling the levels of multiple sources (such as mix stems and audience mics); the wireless receiver should have a level control; and the wireless transmitter must have a built-in limiter to protect your precious hearing. Earphones of your choosing are connected to the wireless receiver. Many differences exist in personal monitor systems, but the Shure P4MTRE3 has all of the features just described.
Earbuds have several advantages to wedges and headphones. Because they aren't open-air monitors, they're not nearly as susceptible to feedback. Some companies even offer custom-molded earpieces (such as Ultimate Ears and Sensaphonics) created from an impression of your ear canal for a perfect fit. Depending on the manufacturer, custom earpieces may be proprietary or work with select third-party earphones. Despite the barrage of headphone-wearing DJ images in the media, wearing nothing at all, or at least looking like it, is still ultrachic.
If you just play local bars and pool parties, you're not going to need an enormous stage-monitor system. A pair of powered P.A. speakers will work just fine. But as you play larger venues, personal ear monitors become a crucial investment not only to better your monitoring setup but also to improve your playing and protect your hearing.