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How to Set Up a PA System

PA System Setup Guide

In this guide, we will show you how to set up a PA system. Whether you’re using a portable speaker with a single microphone, or a large mixer with multiple amplifiers and speakers, we’ll walk you through the setup basics and show you a few examples. Follow the sections below to get started.

What is a PA system?Set up to prevent feedbackHow to Set Up a PA SystemPresenter or karaokeSinger-songwriter or musicianBand or music groupLarge performance venue

If you are new to using a PA system, then you’re in the right place. The primary goal is to amplify a sound source to your audience, and we’ll show you how to go about doing that. To get started, first learn what a PA system is and how it’s able to amplify sound without producing feedback. Once you’ve got a hang of the basics, learn a few different examples of PA’s you’re likely seen before.

A public address (PA) system is for amplifying the human voice. In its simplest form, it has a microphone, mixer, and loudspeakers. It all starts with the microphone (mic), which converts sound pressure to voltage. That means when you speak or sing into the mic, its magnetic force outputs a small amount of voltage. That voltage is then sent to either a mixer or loudspeaker for amplification. Once boosted by a power amplifier, the voltage is so high that it forces the speakers to move and recreate the sound pressure changes which first entered the mic. The result is a much louder sounding voice.

Another way to think about amplification is how the signal level, or its voltage level, is increased at separate gain stages of the system. Gain staging refers to each level of preamplification or volume adjustment found in a signal path. For a PA system, the gain stages are the microphone preamplifier, channel level, mix level, and loudspeaker level.

The voltage starts at mic level and, after being increased by a preamplifier gain knob, is increased closer to line level. Once raised to line level, the signal level is adjusted by a mixer’s level controls. When the mix leaves the mixer and enters the loudspeaker’s amplifier, it is dramatically increased to speaker level and controlled by the amplifier’s level control. The high voltage level causes the speaker to rapidly move back and forth, thus reproducing an amplified version of your original signal.

Mixers let you connect and control levels that are received from microphones and sent to speakers. Their main function is to bring microphone and instruments levels up to line level and then balance the mix before sending it to the loudspeakers. Learn more about how to set up a mixer.

The real difference is where the power amplifier is located. In a powered speaker, the amp is inside the cabinet with the speaker. In a passive speaker, the amp is a completely separate device mounted in a rack separate from the speakers. While you’ll use similar cables to connect a mixer to either loudspeaker’s amplifier, connecting passive speakers to their amplifier requires an additional Speakon or ?” speaker cables.

How to prevent feedback is one of the most fundamental PA system rules. Feedback is what happens when a microphone pickups up too much of its own signal. When this happens, the amplifier outputs a louder version of the signal, and a loop is created. The result is a ringing tone which gets louder and louder until the feedback loop is interrupted. The big idea with feedback is that you want to keep the sound from the speakers from getting into any of the microphones.

The number one way to prevent feedback loops is by never pointing microphones and speakers directly at each other. If a feedback loop occurs, you can stop it by muting the offending speaker or microphone, but the most reliable option is to take feedback loops into consideration when positioning each mic and speaker. Main speakers should be placed in front of the microphones and pointed away from the stage. This helps each mic reject the amplified sound sent to the audience. Stage monitors are often prone to feedback because of their proximity to each performer’s microphone. Increasing their distance apart from each other will help, but facing the speaker so it’s rejected by the microphone will produce the best results.

Always keep the maximum practical distance between mics and speakers.Never place the main speakers behind microphones.

Always speak or sing within 1”-3” from a microphone windscreen.Never point the microphone directly at a speaker.

PA systems can be used for a variety of purposes and thus can be set up in a variety of configurations. Below, we’ll show you a few common ways for setting up PA systems. Since every setup will be a little different, we recommend you view each and then determine which type of configuration works best for your setup. Check out each PA systems setup example below: presenter, singer-songwriter, full band, and large venue.

The simplest job of any public address system is amplifying a single microphone through a powered speaker. The amplifier receives signal from the microphone, amplifies it according to the speaker’s level control, and then outputs sound from the speaker. Some portable PA systems even have EQ and wireless connectivity options for ease of use. If you need to play music from a smartphone, computer, or disk player, they can usually be connected via a wired (Phono/TRS) or wireless (Bluetooth) option.

Mixer: Built-in to speaker/system or not required.Loudspeakers: At least one, often capable of linking a second speaker.Microphones: One or two standard dynamic microphones for voices. Some systems have built-in wireless features for connecting specific microphones.Other: Both active loudspeakers and all-in-one systems might have EQ and level control.

Excellent for presenters and portable amplification (some have rechargeable batteries).Perform a quick sound check to set the microphone level.Speak or sing within 1 – 2” of the microphone.For small spaces, rely on the acoustic sound and mix the speakers in.

Most mixers have the same features and controls but vary in the number of channels for connecting microphones and instruments. That means when you need more mics, you need more channels. A mixer with a couple of channels allows you to mic a voice or instrument (like guitar or piano), mix them together, and then output them through one or two main speakers.

Once connected, you’ll use the mixer to adjust the microphone and mix levels sent to the speakers. Some small mixers even have aux outputs for sending a unique mix to a performer’s stage monitor speaker. The same setup rules apply: point the speakers for optimum coverage, avoid positioning gear in feedback loops, and set sufficient gain levels.

Mixer: Mixer is separate from speakers and varies in the number of inputs and outputs.Loudspeakers: One or two connected to the mixer’s main mix. You could also connect one or two for the mains, and (if your mixer has an aux send) another as an optional stage monitor.Microphones: One or two standard dynamic microphones for voice and acoustic instruments.Other: If you don’t have a ?” guitar input (aka Instrument or Hi-Z) a DI box will be necessary to connect electric keyboards or guitars to a microphone input.

Perform a quick sound check to set the microphone and speaker levels.Place mics 1-2” away for voices and 4 – 5” away from acoustic instruments.Rely on the acoustic sound of the performer and reinforce their sound with the PA system.Two main speakers provide wider coverage for larger spaces or audiences.An external mixer (soundboard) allows for more mics, instruments, and speakers.If you don’t have an instrument input, use a DI box to connect an acoustic guitar or keyboard to an XLR microphone input.Boom mic stands (short/tall) for better positioning microphones.Some mixers can connect an additional stage monitor via an aux output.

A typical band might require mics for drums (kick, snare), bass guitar (mic or line input), electric guitar (amplifier mic), keys (stereo line inputs), and a few vocalist microphones. Channels add up fast, so an ideal mixer is one that has enough. In this case, you’ll likely need a larger mixer with additional channels for mics, aux sends for stage monitors, and a stage snake to make setup easier.

The setup process is the same, but you’ll need to give more attention to gain staging and feedback prevention. Typically, the more microphones and speakers you add to a system, the more likely you are to experience feedback. Do your best to point the bottom of the microphone at the speakers or monitors. That’s the least sensitive part of the mic, so it really helps to keep it from picking up the sound of the speakers and stage monitors.Common gear

Mixer: An external mixer with enough channels for a full band and aux outputs for stage monitors. Built-in effects and signal processing allow for greater control.Loudspeakers: Two main speakers are standard, but stage monitoring depends on the mixer: usually up to four stage monitor loudspeakers, each with a unique mix.Microphones: Dynamic mics for vocals, guitar amp, snare, and toms. Kick/bass drums require a unique microphone for low frequencies.Other: Use DI boxes to connecting instruments (like bass guitar) to microphones inputs. Use a stage snake to replace long cable runs.

Larger mixer to accommodate more mics and stage monitors.Use speaker stands to elevate the speakers to the audience’s ears.Soundcheck to set the microphone level, create a main mix, and then adjust monitor levels.Position drum mics up close and point them at the center of their drum head.Always point mics away from stage monitors to prevent feedback.Instead of turning guitar amps all the way up, turn them down and use a microphone to put the guitar amp in the PA.Use a DI box on bass guitar so you can connect it to the amplifier and a mixer channel at the same time.

When you go to a concert venue, you’ll probably first notice a large number of speakers. This is because the biggest challenge of a large space is adequately amplifying the performer throughout the entire venue. To do this, the system requires more powerful (or just more) amplifiers, and thus speakers, too. These amplifiers will accommodate the additional mains arrays, subs, stage monitors, and any other speakers the venue may need.

Since low-frequencies require a lot of energy to reproduce, larger venues will need a lot of large speakers with enough power to create the low-end thump you can feel. Subwoofers (subs) are speakers dedicated to reproducing low frequencies. They can be configured along with the main mix or output a unique tailored aux mix (e.g., kick and bass). Positioning subs will vary from venue to venue, so just consider how its placement will affect how the entire system sounds, and make adjustments for balance. Placing subs or speakers near walls will make them sound louder, and possibly unbalanced.

As the stage grows, wireless systems become a convenient solution for performers who move around during the performance. That means you could find additional wireless microphones and/or in-ear monitor systems on the side of the stage. You might also see a second mixer on stage, which is is operated by a monitor engineer who specifically manages the monitor mixes.

Mixer: Large channel count mixer, typically digital. A second mixer can be used on stage strictly for monitor mixes. Digital stage snakes are often used in conjunction with their compatible mixers.Loudspeakers: Mains speakers are made from several speakers connected in an array. Several subwoofers are required to reproduce low frequencies.Microphones: Lots of dynamic mics to accommodate any setup. Unique microphones for vocals, guitar, and kick drum are often used.Other: Back up microphones, cables, and DI boxes to make sure the show goes off without a hitch.

Perform scheduled sound checks well in advance of the performance timeMix stage monitors or in-ear monitoring systems from an additional Monitor mixer.Digital mixers can save and recall scenes for complex or frequent band turnovers

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