What is included in a PA system?
High-quality public address and voice evacuation systems are essential for dealing with security and safety challenges. To be truly effective, a public address and emergency sound system must deliver exceptional performance and reliability. The company has provided systems and components for major transportation terminals, houses of worship, public buildings, office buildings, schools and shopping malls around the world. The simplest, smallest PA systems consist of a microphone, an amplifier, and one or more Loudspeakers. PA systems of this type, often providing 50 to 200 watts of power, are often used in small venues such as school auditoriums, churches, and coffeehouse stages. For Large space like stadium, concert place coverage 1000W+ sound wave power is required …
Microphones
The microphone is the first component of most any public address, or PA, system. Technically speaking it is a "transducer", which is just a fancy name for something that takes one type of energy and converts it to another. In the case of a microphone, acoustic energy (sound pressure) is converted to electrical energy (a voltage). Microphones are designed to accomplish this transduction in a number of ways, but most use either electromagnetism or a large capacitor. Although there are tons of different kinds of microphones on the market, the most common design is called a dynamic microphone which uses electromagnetism. The two most popular dynamic microphones used for live sound include the handheld microphone and the lapel microphone.
- Handheld microphones are just that--held in the speaker's hand or placed in a specially designed clip.
- Lapel, or lavalier, microphones are also pretty self-explanatory, as they clip right onto the lapel of the speaker's clothing.
Cables & Wires
Most microphones use XLR, or 3-pin, connector cables but some use 1/4" TRS jacks. A few even connect with smaller 1/8" headphone-style jacks. In any case, the cable connects to the microphone on one end and the input of the mixer on the other. The same or similar cables are also used when connecting the mixer, power amp, and loudspeakers together. While most microphones feature a wired design (meaning they are connected directly to the sound system with a cable), some are wireless. Wireless receivers are ideal for interactive presentations where the presenter moves around a lot or takes questions from audience members. There are two things to keep in mind when using a wireless system: battery power and frequency. Because the microphones are wireless, they require some type of disposable or rechargeable battery. In a wireless system, the sound signal is transmitted over a specific frequency much like a cordless telephone. If you are using more than one wireless system, be sure that they are set to different frequencies. Otherwise the signals may cross over causing one or both signals to drop out entirely. 
Mixers
Mixers allow multiple sound sources to be blended together so they can be played out of the same loudspeakers. Mixers range from single input designs to very large elaborate mixing consoles and desks with hundreds of inputs. Sound sources such as MP3 players and laptops can be plugged directly into the inputs without a microphone when background music or supplemental audio is needed. Just be sure to adjust the output level of your music playing device accordingly to avoid overloading the system.
Amplifiers
The amplifier is the next part of the chain. Amplifiers, or amps, electronically increase the level of the initial sound source. Sometimes mixers come with built-in amps, which simplifies the setup process for the user. If the amp is not built-in, separate cables are needed to transmit the signal from the mixer to the amplifier. All-in-one designs are called "powered mixers". Most of the models we sell are designed as all-in-one, or boxed, units so that setup is easier for the user. In some cases, the loudspeakers include built-in amplifiers rather than the mixer, but most loudspeakers are "unpowered", or "passive" and must be connected to a separate amplifier to generate sound. 
Equalizers
An equalizer is basically the tone control. Most mixers that accompany a portable PA system use relatively simple filters. They allow you to dial in bass, mid-range, and treble adjustments. Stand-alone graphic and parametric equalizers provide much more flexibility in tailoring the frequency content of audio signals. Equalizers adjust the amplitude of audio signals at particular frequencies, so they are, essentially, frequency-specific volume knobs that control the tone. 
Faders
A fader is the sliding control usually found on the mixer. Its function is to organize each channel’s level and bus assignments. It also includes mute and solo buttons that allow you to isolate what is going on in each channel. A fader can be either analog, directly controlling the resistance or impedance to the source (such as a potentiometer), or digital, numerically controlling a digital signal processor (DSP). Digital faders are also referred to as virtual faders, since they can be viewed on the screen of a digital audio workstation. 
Loudspeakers
Loudspeakers are the final piece of the public address system and reproduce the amplified sound. Think of the loudspeaker as the opposite of a microphone. Although they are both transducers, the loudspeaker converts an electrical signal, or voltage, back to acoustic energy. Most importantly, the reproduced sound is much louder than the original source. Loudspeakers utilize a variety of different cables depending on the manufacturer, but most work with the aforementioned TRS and XLR connections. Check your specific model for details on how to connect it. In rare cases, special adapters are needed to run the signal from the amplifier to the loudspeakers. Most of our PA systems come with all the necessary components and cables for simple setup but you may encounter other situations when dealing with other manufacturers’ equipment. Loudspeakers are available in a variety of different sizes and wattages. It is very important that users select the right wattage and impedance when connecting them but again most all-in-one PA systems (including the models we carry) feature loudspeakers that are perfectly matched. If you are unsure about the compatibility of your components, read the included manual or contact the manufacturer directly for details. 
Total System network
