The type of stage monitor speakers needed is dictated by the choice of the performer who will be using it. Some vocalists, and even some musicians, prefer what is known as a personal monitor, or "hot spot" monitor. This is a small speaker box that is either attached to the microphone stand or placed near the musician (keyboardists and drummers often use these stage monitor speakers). This type of monitor does not require a great deal of power, and consequently the speaker is smaller in size.
The personal monitor is fairly easy to construct. A basic speaker box (square-shaped is sufficient) housing one speaker with wiring is all that is needed. The top, bottom, and sides can be all one dimension, with the speaker mount (baffle) cut to fit into the front of the enclosure. In other words, you can build a square box (medium-density fiberboard or ½ inch plywood work well). An 8-inch or 10- inch speaker is mounted onto the baffle, which is then glued and/or screwed into place within the enclosure. 16-gauge speaker wire is attached and run to the installed plug jack and then attached. A standard threaded fitting that matches the microphone stand threading can be found at nearly any hardware supplier, and then mounted on the enclosure. The important thing, of course, is to match the impedance of the speaker to the power amplifier in the sound system. This is true for any stage monitor speaker.
The popular wedge-shaped stage monitor speakers are slightly more involved, yet the idea is of a basic box. The only difference is that the top and side sections of the monitor are cut so that the speaker baffle is pointed up toward the performer (the angle is generally around 45 degrees). Some wedge monitors are made with two back pieces joined together in order to create the option of different angles of sound projection. In the case of all larger stage monitor speakers, the baffle is best mounted up to 1 inch inside the front of the enclosure. This is accomplished using a drill with a 1/2-inch router bit cutting a groove into the side sections, into which the baffle is secured.
These speakers are especially useful for larger venues. They are similar to the front speakers in design and function, with the only difference being that they are pointed inward toward the performers from the side of the stage. Side fills will usually carry the signal of all the vocalists and instruments, so they are more suitable when combining a driver and a midrange horn. This will provide a full range of sound reproduction. The design is most often a rectangular enclosure, with holes cut in the baffle for the horn and the driver. A crossover will be needed for this type of side fill enclosure, and the wiring must match polarity between the power source, the driver, and the horn.