PA setup basics
This particular article is aimed at educating students and teachers at schools and colleges and even corporate executives, about some very simple basics of an audio setup. And how to decide upon and use such sound equipment better on their campus / auditoriums.
In many cases, the sound vendor throws in his own ideas and could end up guiding students on where to stand on stage, what to do or not while using the sound equipment. And this may not be entirely true! Many feel intimidated by so much “gear” and thus donot approach the operator also! So what does one do?!
The basics explained here will help you negotiate better with vendors and hopefully help you improve the performances on stage: audio-wise. The end-result? Give your audience a better experience of seeing you all put up a great event.
Note: the images in these articles have been borrowed from the Internet and are the property of their respective owners.
PUBLIC ADDRESS (P.A.) SYSTEM
Each PA system consists of a mixing board (mixer), sound processing equipment (microphones, stands, cables), power amplifiers, speakers, sub-woofers… And a sound operator. In situations where power fluctuations are possible, a generator is also added to the list.
The events at your school / college could be of any kind: a speech / musical show / drama / dance or a mix of all. Based on factors like the venue (outdoor / indoor), audience strength, etc. and your event’s content helps the sound vendor decide on the list of equipment to bring and setup.
MICROPHONE BASICS
Microphones (mics) are a type of transducer – a device which converts acoustical energy (sound waves) into electrical energy (the audio signal). Different types of microphone have different ways of converting energy, but they all share one thing in common: The diaphragm.
DYNAMIC MICS
- Have relatively simple construction, and are therefore economical and rugged.
- Are most commonly used for stage shows in schools and even music concerts.
- They may or may not have an On/Off switch.
- Are usually wired.
- Ideal for vocals and drums.
CONDENSER MICS
- Are based on an electrically-charged diaphragm/backplate assembly which forms a sound-sensitive capacitor (historically called a ‘condenser’).
- Most commonly used in recording studios and controlled environments like concert halls. They provide higher sound quality than dynamic mics. Can also be kept suspended from the ceiling in plays / dramas to cover more area.
- Can be wired or wireless too. Are a better choice for acoustic guitars.
- Very sensitive to sound signals from quite a distance also. So these have to be turned off with the switch (if any), when not in use.
TYPICAL MIC TERMS TO KNOW
1. Leakage:
Each microphone captures sound signals from a distance source. So a guitar mic can capture the loud sounds of a drum being played near it.
Hence it is important to keep musical instruments (especially drums) in a particular style on stage to avoid “leakages” into another mic, and avoid muffled audio.
Too many mics on stage should also be avoided being very close to each other.
2. Feedback:
This is the condition that occurs when an amplified sound enters a microphone and is re-amplified until a steady howl or whistle is heard.
So never go ahead of a speaker box with mic in hand, or keep speakers too loud either.
Omni-directional microphones pick up sound with equal gain from all sides or directions of the microphone.
This means that whether a user speaks into the microphone from the front, back, left or right side, the mic will record the signals all with equal gain.
WEDGE (or Foldback) stage monitor
- This “monitor” reproduces the sounds of the performance and directs them towards the on-stage performers to help hear the instruments and vocals.
The audience listens to this same audio, but from the PA speakers facing them. - Keep atleast 3 wedges on stage – Left, Centre and Right corners. Usually lead instrument players need one.
- These monitors usually are balanced differently. But in school or college or low budget scenario, the balancing remains the same as the PA output.
- The PA should ideally have a proper speaker distribution system for better sound. This is highly dependent on factors like closed venue or open to sky amphitheatre, the size of the venue, audience strength. The decision is usually taken by the sound vendor. And again is budget dependent.
- Instead of having a costly distributed system, a better and economical solution would be to get the PA in the correct position & preferably height.
an example of a distributed speaker system
DO’s and DON’Ts on-stage
1. A microphone is neither an ice-cream cone nor a lollipop 😊 So do not hold it like one. Doing so makes your voice sound thin!
Ideal distance between mic and mouth: 3 to 6 inches.
2. Hold the mic (cordless or wired) from its middle portion.
Grasp it with all your fingers. But don’t squeeze it hard either.
Ideal angle while speaking: 45 degrees (rear-end towards the floor).
3. When there is a gap between use of a cordless mic, keep its switch OFF.
Else everything you speak backstage will be heard by the audience!
4. Before an announcer speaks (or even comes) on stage, make sure the mic switch is kept ON.
Else it becomes embarrassing to fumble with the switch while on stage.
5. Do not tap the mic with your fingers, or blow into it, to check if it is on or not.
Check the on/off status by speaking words into the mic like “Check 1-2-3”, or “Hello parents”.
6. Do not cover a mic with your hand when talking to someone else on / off stage.
If you want to clear your throat or cough, do it by keeping your mouth away from the mic.
7. Adjusting height of a microphone stand.
Based on the next act, keep the height of mic stands pre-adjusted if possible, as per the performer’s height.
Instead of the child adjusting the height of the stands, the volunteer(s) can quickly, but quietly (no shoes on), come on stage and do this. Some practice on how to do this during rehearsals helps.
8. For group (chorus) singing, position the children and mics as seen in this example and distances mentioned. The Mic angle and the stand height should also be properly set.
An ideal solution for group singing on stage is suspended mics – if it is possible to do so. Condenser ones are preferred to cover more area on stage.
If there are say 6 children, keep three kids in front and three taller ones behind them. Keep 2 mics suspended 1 feet above their heads, 2 feet apart and hanging a little ahead of the first row. The children should stand a little behind these mics and sing at full voice. They should not look up towards the mic while singing. Extrapolate the number of mics for more children in the singing group.
9. For acoustic guitar miking, the safest place to point the mic is the area where the guitar’s neck and body meet at a distance of 3-4 inches. Condenser mic is recommended.
10. For miking a Djembe or any single drum instrument, keep it at a distance of 6-8 inches to avoid hands hitting the mic, and allowing free playing of the instrument.
…a professional drum miking setup
11. Befriend the sound operator. And call him by his or her name, and not as “soundwala bhaiyya”.
Those students / teachers assisting the operator should try and make him feel that he is a part of the show. And he is. This will ensure you get better co-operation.
12. For the Video camera setup: Get the audio output from the mixing board into the camera directly for best results. The videographer should not record the events with the camera mic as far as possible. A balanced audio cable with a DI (Direct Injection) box in between the mixer and camera input is highly recommended for equipment safety. This technical detail he should co-ordinate with the sound vendor in advance, and not on the day of rehearsals or the show.
13. All wires and cables running across / near the stage, in the audience area (especially around the video setup), near the lights, etc. should be safely sealed with safety gear, or taped to the floor properly. This is to avoid any accidental tripping by performers as well as the audience.
Inspite of these tips and suggestions, mistakes will happen on stage. And that’s perfectly fine. Nothing can beat the enthusiasm and efforts put in by the participants on and off stage. Enjoy your events.
To know some simple steps to check the sound of a PA system, read part 2 here >>