An Introduction to Pro Audio PA Systems

Public speakers, acting troupes and musicians commonly use public address (PA) systems to provide sound reinforcement. Essentially, a pro audio PA, called a Tannoy system in the United Kingdom, is a portable loudspeaker system that accurately disburses sound throughout a large area, such as an arena. The PA increases the loudness of acoustic and electric musical instruments, the human voice, and pre-recorded music or sound.

When should you use a pro audio public address system?

Use one of the simple, portable systems in small venues like churches, community or school auditoriums, or bars/pubs. These systems use between 50 to 200 watts of power. Use the larger systems in arenas or stadiums as these use a 1,000 or more watts of power. Permanently installed versions appear in commercial, institutional, and public buildings like shopping malls, schools, and fairgrounds. These loudspeaker systems let an individual make announcements to every room of the building or area of an outdoor gathering place simultaneously. These systems amplify the sound to a 50-volt, 70-volt, or 100-volt speaker line level.

Pro Audio PA system components

The equipment used for sound reinforcement includes a number of pieces designed to create accurately amplified sound. These include the following equipment:

  • Amplifiers (amps)
  • Microphones
  • Mixers
  • Monitors
  • Speaker cabinets
  • Subwoofers

While some may refer to the speaker cabinet itself as a u001aPA,u001a a PA system includes that device, plus multiple microphones, a mixer, multiple amplifiers, and speakers designed for high volume and wide distribution. The mixer is also called a mixing console that lets the audio engineer control sound level, combine, and modify every sound source u001a usually instruments u001a feeding into the mixer. The monitor system, referred to as the foldback system in the UK, reproduces the instrument's performance sounds and directs them back to the performer onstage. Each performer typically has his or her own monitor.

How do active and passive cabinets differ?

The speaker cabinets come in two essential designs: active and passive. An active cabinet includes built-in power amplifiers and electronic crossovers. This lets the sound engineer directly connect the speaker cabinet to the mixing board (mixer) output. You can daisy-chain these devices to grow the system to your needs.

A passive cabinet houses only speakers. It requires an external power amp. To use it as a bi-amplified system also requires an external electronic crossover in addition to separate amps for low- and high-frequency audio. The separate pieces of this cabinet type require a lengthier setup time. It does enhance system flexibility since if one amp breaks, you can replace it with another.

Public address system options

Choose from systems with two-way or three-way, amplified, battery-powered, or full-range configuration with input gain control. You can find portable, wireless systems. Modern PA systems offer a plethora of RMS power options. These include wattages beginning in the 100-249 watt range and ranging up to 2,000 watts or greater.

Who manufactures pro audio PA systems?

Youu001all find systems from Behringer, Electro-Voice, JBL, Mackie, Peavey, Pyle, RCF, and Yamaha. These manufacturers offer both active and passive cabinets.