Improving Your School Programs and Events by Better Miking Solutions
By: Gene Houck
It is a scenario that is being played out all across our schools. After all of the practice for a school performance-be it a play, choral event, concert band, or speech-when it finally arrives, you sit in great anticipation, only to find that the students look great, but you can barely hear them. What is going on? Well, it really is more what isn't going on or being properly used-microphones.
Even if an auditorium has a public address system, it is more common than not that the PA system does not have the right microphones, nor are they being utilized properly. We are going to touch on some of the most common problems for miking these special school events.
First of all, let's discuss what microphones are doing. A microphone is a "transducer." A transducer converts energy from one form into another. In the case of microphones, they are converting acoustic (sound) energy into electrical energy (electrical current). They are, indeed, the first link in your signal chain and, as such, are extremely important. Bad sound in means bad sound out.
Your loudspeakers are also transducers, converting electrical current or energy back into acoustic or sound energy. In the sound world, there is a very accurate saying, "Don't compromise your transducers." That means do not take most of your sound reinforcement budget and spend it on that fancy mixing console with all the pretty lights and knobs and forget about the microphones and loud speakers.
Unfortunately, when it comes to a sound system for auditoriums, gymnasiums, or other performance venues, schools very often forget about microphones, even if they own or obtain adequate loud speakers. Consequently, schools often purchase inferior microphones or microphones not designed for the purpose for which they are being utilized.
Dynamic vs. Condenser
There are two types of microphones that you will be utilizing. The choice between dynamic or condenser mic is dictated by the distance to the sound source. A dynamic microphone is what is commonly used as a wired handheld vocal mic. They can also be effective for individual singing, close miking instruments, close range speech, and public address. They are rugged and generally less expensive than condenser microphones.
A condenser microphone, however, is better suited for distance miking or capturing an area because of their higher sensitivity and output. Condenser microphones (and there are many types) require phantom power (provided from the mixing board).
If you have an older mixing board that does not provide phantom power, you will need an external phantom power supply. They can be obtained for around $100 and provide two channels of phantom power.
Unfortunately, many schools are utilizing dynamic microphones on stands to capture areas such as choir, theatrical productions, and orchestra. Condenser microphones with their greater sensitivity and output provide the optimum performance for these types of applications.
Taking the Drama Out of Miking Plays
It may be true that in smaller acoustical pleasing rooms just projecting your voice may be all the audience needs. Unfortunately, most environments are not ideal, particularly when trying to hear a timid fourth grader just trying to remember their lines. For most theatrical performances, area miking techniques will vastly improve the experience. Boundary mics are a popular low profile solution. Boundary mics are flat surface mics that work well when placed downstage. When using a boundary mic for theatrical purposes, always use a unilateral direction pattern. This will be either Cardiod (heart shaped) or Hyper-Cardiod (tighter pattern on the sides). A uni-directional pattern will help to reduce feedback and restrict audience noise from entering the sound system.
If the stage area is small enough, try just one boundary mic center stage and no more than three feet away from the most downstage performer. If you are missing dialog on the sides, you will need to add more mics. Avoid having the front of the mics facing each other; it is better to either have them line up parallel or have the back of the mic (where the cable connects) face each other slightly. In all "area miking" cases, whether it be a theatrical production or a choir, the fewest mics that can be used is best. Remember that whenever you double the mics on a given sound source, you have a drop of 3 dB of gain. So, the fewest mics possible will provide the most gain before feedback. When using boundary mics, you can help to eliminate excessive floor or foot noise by placing a piece of felt underneath the mic.
Hanging small condenser mics can also be effective. They are most effective when they are kept no further than three feet in front and three feet above the nearest actor downstage. If this creates a line of sight issue, then boundary mics are necessary. Oftentimes, boundary mics are used in front of the actors on the floor downstage, and one or two hanging mics are used to pick up the actors in the back or "up stage." Remember that, a boundary mic will be good for about 30 feet. Beyond that, you will need extra mic coverage. If you find that you need more coverage "up stage," and hanging a mic is not an option, use a boundary mic on a prop or wall. The flatter more reflective the surface, the better. You can use gaffer tape (leaves no residue and can be purchased online) to adhere to a wall. Make sure not to cover the front mesh part of the microphone.
If individual mics are needed, mics either on the actor's clothes or pinned in the hair provide the best pick up and flexibility. The use of a wireless mic system is typically needed for mobility. Multiple systems can be utilized simultaneously. Although the price tag goes up considerably from "wired mics," be careful not to invest in the most inexpensive wireless systems you can find.
Miking a Choir or Choral Group
Once again, the use of a condenser mic is really a necessity. Condenser mics for choirs come in all sizes. For the most part, this type of performance is set up different ways at different times. Most schools do not have a permanent structure in place for a choral group, but instead will set up risers as needed. This means that condenser microphones on stands become necessary.
Once you have your condenser mics, the biggest challenge is mic placement. It is rare to see mics placed properly to adequately cover back rows when three or more rows are utilized. Place the mics 18 inches to 2 feet in front of the first row. Adjust the height of the mic to 18 inches to 2 feet (match the distance of the first row) above the tallest singer in the back row. Point the mics to just above the mouth of the tallest singer in the back row. This enables the mics to be equidistant to all the singers and helps eliminate the front row from overwhelming the mix.
If trying to mic three or more rows of a choir or choral group, you can see from the above suggestion that mics need to be fairly high. It is difficult for a standard mic stand, or even a standard mic stand with a standard boom arm, to adequately reach this required height.
Public Speaking Made Easier
There is often a need to mic a public address, commencement speech, or awards ceremony. Whether you are using a lectern mic or just having a mic on a stand, it is good to know ways to maximize the audibility of the speaker. Dynamic mics and condensers can be used for this purpose. Remember, however, that condenser microphones are more sensitive than dynamics microphones. Since many of the speakers will be at a greater distance than an inch or two, condenser microphones are recommended for this application in order to create a larger pick up area Avoid having the speaker to close (within one to three inches). There can be some nasty pops if the speaker is too close to a podium mic. Also, understand that doubling the distance of the speaker to the microphone will drop the sound level by 6 dB. That is a ton and extremely noticeable.
The answer is setting the gain structure with a large enough pick up area so that the speaker can communicate naturally with their own personal style of gestures and every word is picked up nicely. Condenser mics will offer the best sensitivity for this application.
Applying these guidelines will go a long way to ensuring a memorable and audible school event or function. Remember, though, they still need to practice their lines or memorize their lyrics!
Gene Houck is the national sales manager and director of Christian artist relations for Audix Microphones, www.audixusa.com .
