How to Choose the Right PA System
Choosing the right PA system is vital. Here are some tips to choose the right one.
According to musiciansfriend.com:
“As a performing musician, capturing, mixing, and amplifying your sound involves choosing a live sound system that’s well matched to your music, budget, and the venues in which you play. Whether you’re a singer-songwriter performing in a café, a band playing in a local bar or club or a DJ playing weddings, you’re going to need a PA system to be heard. In this guide we’ll walk you through all the live sound gear you need, tell you how it works, and help you find the right PA equipment to make your music sound its best.
“As a performing musician you want a PA system that can deliver your sound with clarity and definition. But with so many different pieces of equipment designed for different live performance needs, it can be difficult to know just what it is you should be looking for.
“Certainly, there are a lot of variables to consider when choosing a PA. For instance, you’ll need to think about the size of your audience, where your performances will be, how portable you need your system to be and how much money you can invest.
“This guide will help walk you through these and other important considerations to help you find the gear that’s right for you, whether you’re buying your first PA system or looking to add equipment to your existing system.
What is a PA System?
“In short, a PA system is a public address syste. Also known as a sound reinforcement system, a PA system is an electronic amplification system used to get sound from the performer(s) to the audience. It’s made up of several components, and while one system can vary greatly from the next, each one handles these same basic functions:
“Converting acoustic sound into electronic signals, most often with microphones or line inputs.
“Processing and mixing these electronic signals, using mixing boards and effects modules
“Amplifying signals with a power amp
“Delivering the sound through speakers
“Monitoring the performance with speakers or in-ear monitors
“Different PA equipment will have different capabilities, features, and designs associated with each of these functions. Your specific needs will determine what you want out of each.
Prepackaged PA Systems
“If you don’t want to get too deeply into the nuts and bolts of PA equipment, you might want to consider one of our complete, live sound PA system packages that include everything you need to get up and running. If you’re new to PA gear, these systems can help you avoid the problems that can arise from mismatched PA components. And by purchasing bundled gear, you can save a lot of money.
“Musician’s Friend carries prepackaged systems from great brands like Yamaha, Fender, Behringer, JBL, Peavey, Mackie, Kustom, and many more—all at the best prices you’ll find anywhere—guaranteed.
All-in-one Modular PA Systems
“For solo acts, duos and other smaller groups that play in venues lacking a built-in PA, a modular tower system can be a clean, simple way to get heard with a minimum of fuss. These systems typically house a speaker array, mixer and power amp in a single, column-like structure that breaks down for easy transport. Because the components have been optimized to work with each other and the speaker arrays are designed to generate high-quality, room-filling sound, these systems offer an affordable, portable option to standard PAs.
“The JBL EON ONE PRO Linear-Array PA System is an excellent example, delivering robust sound that’s highly intelligible and runs off of lithium-ion battery power. JBL engineers have created an array that serves up pro-quality sound to every corner of the room. An 8” subwoofer adds the kind of bottom end that can sometimes be a weak spot in similar systems. With its Bluetooth streaming capability, you have the option of going wireless—a great feature for active musicians, instructors, and other presenters who roam the stage or room. There’s also a USB port to keep your mobile device plugged in and charged, with no fear of running out of juice. The 6-band mixer is simple to use and lets you easily connect all your gear. Per-channel Treble and Bass control helps you dial in your sound with independent channel volume controls, a master volume and an onboard reverb.
“Other modular PAs to consider include the Bose L1 Compact System with its two inputs, it’s a solid choice for singer-songwriters. The 1,000-watt Electro-Voice Evolve 50 houses a 2-channel mixer, Aux In, plus eight 3.5″ neodymium drivers and a 12” woofer. The Harbinger MLS900 Line Array PA System features a diverse range of input options, including Bluetooth, and it delivers 900 watts of powerful sound.
Portability vs. Control
“One important question to start with in your PA system search is ‘How portable do I need the system to be?’
“Traditional PA systems are made up of separate pieces of equipment for each individual function: a standalone mixing board, outboard signal processors, dedicated power amp(s), and a number of individual PA and monitor speaker cabinets. Such systems require considerable space to transport, store, and set up onstage.
“If you need to transport your PA system frequently to different venues that have modest amplification needs and crowded performance spaces, there are portable, compact PA systems likely to meet those needs. In fact, there are even complete PA systems that include all of the necessary equipment within a single enclosure, roughly the same size as a standard PA speaker.
“For small groups or solo performers who play in small venues with basic amplification needs, there are some excellent all-in-one models that deliver plenty of power. The Yamaha STAGEPAS 400i, for example, will handle just about anything you’ll need … but in a package that will fit in the trunk of a compact car.
“That said, super-compact systems also have their limitations. They do not offer as much control, customizability, or sheer sound output as a traditional PA setup. Generally, they can’t deliver the kind of high-power performance needed for larger venues, nor do they provide enough inputs for larger groups, especially those with miked drum kits.
“If you have more advanced live sound needs but are looking for more portable options, you can find powered mixing boards and powered speakers that have integrated power amps, making a standalone power amp unnecessary.
“Keep in mind, though, that powered mixers can still have limitations, particularly for bands that plan on expanding their PA equipment in the future. With individual components handling each function in a PA system, it is easier and usually more cost-effective to switch out, upgrade, and add individual PA components to enhance the system.
PA Power Amplifiers
“One of the most important questions when it comes to PA systems is “How much power do I need?” This is a consideration when purchasing a power amp for the system.The power amp’s job is to boost the low-level signals coming from the mixer and broadcast them through the speakers. How much power it produces is measured in watts. And you want to make sure you’ve got enough wattage to fill the venue without compromising the sound quality.
“Exactly how many watts you need hinges on a number of variables. The most obvious of these is the performance location (room size, indoor/outdoor, acoustics). However, there are additional factors that complicate the issue. For instance, there is the efficiency of the speakers (i.e., how much sound the speakers produce per watt of power). There also is the concept of headroom (how much power it takes to handle peaks without distorting) and the desired volume level of the music.
“Using speakers with average sensitivity, a rock band playing in a medium-sized club will need around 1,500 watts total power at a minimum, whereas a pop or jazz group might need between 250-750 watts. For simple folk music in the same venue, that requirement can come down to as little as 60 watts. Keep in mind though that these power estimates are generalizations; difficult performance spaces and music with a lot of dynamics can require considerably more power. As we note below, factoring in plenty of headroom will help ensure great sound when you’re performing in a challenging environment.
“It’s important to buy an amp with plenty of power to drive your speakers plus enough headroom to prevent distortion. When shopping for speakers, you’ll see that they have a power rating, measured in watts. As a general rule, you will probably want an amp with twice the wattage of your speaker’s rated power handling to ensure a clean, undistorted signal gets to them. We will discuss this further when we cover PA speakers and their power requirements.
“Keep in mind that a stereo power amp provides two channels, each able to drive its own speaker load. So if your amp provides 500 watts per channel, a pair of speakers rated for 250 watts would be a good fit. Note that the rated output for stereo power amps is usually given on a per-channel basis. A rating of “2x450W” indicates that the amp generates up to 450 watts into each of its stereo channels.
What is bridged operation?
“Some power amps have a bridged operation mode. Also called mono or bridged mono, in this mode the load is connected to draw from both channels. That means the amp effectively becomes a higher-powered single-channel monophonic unit, even though both channels are being used.
What’s the deal with ohms?
“One detail on the spec sheet that you want to be sure to check is the ohms rating. Ohms are a unit of measure for the impedance or resistance in a piece of gear.
“To understand impedance, imagine a hose plugged up with gunk slowing the water flow. If you want more water to come out, you have to increase the amount of water at the faucet to increase the water pressure.
“Well, in regard to electricity, this gunk is the impedance (measured in ohms) and the faucet pressure is the voltage. So gear with low impedance lets the electricity flow easily while gear with higher impedance requires more voltage to make the electricity flow.
“It’s important that the impedance rating of your amp matches up to that of your speakers. If it doesn’t, there are ways you can work with your gear to make them match. That is, you can change the impedance of your speakers by wiring them in series or parallel. (We will discuss speaker wiring options a little later.) However, your safest bet is to buy power amps and speakers that match, particularly if you are not planning to expand your system.
“Most PA power amps are designed to handle speakers rated at 4 or 8 ohms with some that handle 2- and 16-ohm loads also. You’ll note when reading power amplifier specs that the rated power output decreases as the impedance (ohms rating) of the speaker increases. For example, the Crown XLS1002 Power Amplifier illustrated above generates 350 watts per channel when connected to a 4-ohm speaker. Output drops to 215 watts per channel when an 8-ohm speaker is connected.
Live Sound Mixers
“Electronic signals from microphones and instruments need to be balanced, processed, and mixed together before they can be amplified and routed to PA speakers and monitors. In your live music PA, this is where the mixer comes in.
“Mixers range in size from simple 4-channel units to much larger consoles that have hundreds of channels. A channel is essentially a signal path. A mixer with a large channel count allows more things to be connected and routed through it.
“Channels are usually designed to accept microphones and/or line-level devices such as amplifiers, preamps, or signal processors. (Microphones and instruments such as guitars and basses output electronic signals that have a much lower level than line-level devices.)
“On a mixer, audio signals are assigned to separate channels, so a fundamental question to start narrowing down your mixer selection is ‘How many channels do I need?’ Generally, you will want to make sure you have more channels than you think you will require. So it’s important to take an inventory of what you will be amplifying and make sure you have sufficient inputs and outputs while allowing for future expansion of your PA system.
“For instance, if you are plugging a standard five-piece rock or pop band in to your PA, your first instinct might be to shoot for an 8-channel mixer. After all, that would allow for five instruments with room to spare. However, once you add up the inputs for everything you need for the group, you will find that your 8 channels actually won’t give you enough inputs.
“With a five-piece band, the live sound arrangement might look something like this: one mic for lead vocals and one for backup (two channels), one mic for the guitar amp, one for the bass amp, and at least one direct input for synthesizers (three channels). Then there’s the drum kit, which will have its own miking considerations. With two overhead mics for cymbals, a mic on each tom, the snare, and the bass drum, you are looking at a minimum of seven mics for a fully miked kit.
“This brings your total required inputs to 12 channels, so you’d want a model with a minimum of 16 channels giving you room to expand.
Getting to know the mixer
“Learning to use an audio mixer might initially seem like a daunting task, with all the buttons, knobs, and faders. But keep in mind that every channel has the same controls. Once you learn how to control one channel, you’ll know how to control every channel.
“Every channel on a mixer is either mono or stereo with an XLR, 1/4” or RCA connection. (Some inputs are designed to handle both XLR plugs from microphones as well as 1/4” inputs.)
“A channel strip is a group of circuits and controls that function together on a given mixer channel to affect the audio signals that pass through it. These usually include:
“an input jack where an external instrument, microphone etc. connects to the mixer. XLR inputs are balanced to minimize noise and interference. Other inputs accept RCA or quarter-inch TRS connectors. Some accept both XLR and 1/4” plugs
a microphone preamp that amplifies the relatively weak mic signal, raising it to line-level strength
equalization, abbreviated as EQ, adjusts the signal’s frequency response in three or more bands
dynamics processing that may include compression or gating (discussed below)
routing that directs the signal to other mixer buses and external devices
a pan control for balancing left and right output
a fader, which slides along a track to control the input or output level of a channel
a meter or light display that visually shows the output of each channel
Getting more control from a mixer
“If you want to be able to make quick adjustments to your mix during a live performance without throwing things out of balance, look for mixers that offer multiple buses.
“Basically, once the levels of each channel are set, the signals are combined into either the main mix or into submixes that can be assigned to buses. Buses can be visualized as circuit intersections where the output from several channels meet. Each mixer channel routes its signals to a specific bus or group of buses. These buses allow you to adjust signals as a group before they go into the final mix and out to the speakers. So, for instance, you can easily make adjustments to all the vocals or all the drums using a single group fader control. Also known as auxiliary sends, auxiliary buses can also be used to route mixes to headphones, external effects processors, monitor speakers, or in-ear monitors.
“You can also make additional enhancements using buses. For example, two-bus mixers normally have a pan control to send a signal to the left or right bus, creating a stereo output. There also may be insert points where you can apply effects to buses before the final mix.
Digital vs. analog PA mixers
“For instant changes to signal routing, flexible and extensive signal dynamics, and an amazing array of effects possibilities, a digital mixer is hard to beat. With the touch of a button, pre-programmed routing and effects can be triggered that would be impossible for even a talented octopus to accomplish on an analog audio mixer!
“Some digital mixers are compatible with software plug-ins that extend their tone-shaping capabilities even further. Recently, many digital mixers have added mobile-device compatibility, allowing operation via a laptop, smart phone, or tablet.
“Our expert Audio Interface Buying Guide will help you choose the right gear to control mixes with your computer or mobile device.
“Digital mixers can also can ride herd on dreaded feedback, preventing the howls and squeals before they even start. Another nice feature is automatic gating that silences channels with little or no signal passing through them.
“One of the huge advantages of digital mixers is their ability to save and recall mixes. Many use USB flash drives or internal memory to store settings from past performances. This makes the set up in a venue that’s been saved fast and simple. Even in a new venue, recalling mixes from similar venues can be a big time saver during sound checks. Some digital mixers let you pre-program mixes using a laptop computer, so when you get to the gig only fine-tuning tweaks to the sound are needed. Some advanced digital mixers have motorized faders that respond to saved configurations.
“Despite the greater versatility of their digital brethren, analog mixers remain popular due to their generally lower cost and ease of use. Since their functions are controlled by physical knobs, faders, and switches, their operation can be somewhat more intuitive than digital mixing consoles. The downside of their reliance on physical controls is the analog mixer’s generally larger footprint—a disadvantage on cramped stages. Many people find the analog mixer’s signal and hardware routing easier to grasp at a glance since everything is physically present rather than being hidden in the menus of a digital soundboard’s many status screens.
“Both analog and digital mixers are capable of transmitting very high quality sound. The quality and design of their electronic circuits—especially the mic preamps—and in the case of the digital mixer, its analog to digital converter (ADC), have the biggest influence on sound quality. Most sound engineers agree that mics and speakers with their inherently greater degree of coloration and distortion are the biggest barriers to absolute sound fidelity. That said, well-designed mic preamps that boost the microphone’s output without adding coloration or distortion are critical to good sound. High-quality circuitry and components in the mixer’s gain stages and signal routing will minimize the hiss that inevitably occurs with analog mixers.
“Browse the huge selection of analog and digital audio mixers at Musician’s Friend.
Powered or unpowered?
“When you browse the Musician’s Friend assortment of audio mixers, you’ll notice that we group powered mixers and unpowered mixers separately to simplify shopping There is only one major difference between these types: Unpowered mixers require one or more separate power amps, while powered mixers have on-board amplification.
“Powered mixers are often easier to transport, less difficult to set up, and are often less expensive. But on the downside, they may offer less power than standalone amps, so they are unlikely to work well in larger venues. And as noted before, powered mixers tend to offer less sophisticated control and fine tuning of sound than non-powered mixers.
“Additionally, buying powered mixers might be less cost-effective in the long run if you plan to make gradual upgrades to your PA system. That’s because you will be replacing both the mixer and the amp when you want to upgrade either component.
Do I need another mixer for monitoring?
“In addition to the main, front-of-house (FOH) mix, you will want your PA system to handle monitoring so the performers can hear themselves. For this, you have a couple of options.
“Often, a single mixing board is used to create not only the main mix, but also the individual mixes each performer needs to hear through the monitors. These mixes will need to meet the different requirements of each performer, according to what each player needs to hear.
“Monitor mixes are typically delivered using the aux send connections on the mixing board. To ensure you and other performers are getting a good mix for performing, you’ll want to confirm that the mixer has sufficient aux sends to route individualized monitor speaker mixes to each performer.
“Another option for those serious about monitoring is to have a secondary mixing console dedicated to the task. Sure, it’s an additional investment, but it can be worth the expense for the quality of sound delivered to the performers.
“Learn more about live sound and recording mixing consoles with our expert Mixer Buying Guide.
Signal Processing (Effects)
“Mixers may have some built-in effects, but if you really want to make your sound stand out, additional outboard processing gear can help add drama and sparkle to your sound. Although they’re not essential in all situations, signal processing and effects such as compression, limiting, reverb, and delay can add sonic interest to your sound that make them well worth the cost.
“Here are some basic effects and signal processing tools that can enhance your PA system:
Compression and limiting
“A compressor as the name suggests compresses the overall dynamics of the audio signal limiting the amount of variation between the loudest and softest sounds.It smooths your sound and protects gear by helping to avoid damage caused by clipping—a speaker-destroying phenomenon resulting from overdriving the amplifier into distortion. Well designed compressors not only prevent signal distortion, but add pleasing sustain to your sound.
“A similar tool, the limiter keeps your speakers and ears from getting blown out by limiting the peaks in the music. A limiter allows compression to occur only above a set threshold, and the compression ratio can be very high. This prevents clipping, distortion, and other related problems.
Reverb and delay
“Reverb (from reverberation) is an effect that makes sounds richer, as if they are reflecting off surfaces. Reverb adds depth and dimension—that’s why your voice sounds better when you sing in the shower. The hard, reflecting surfaces add “space” and drama to your vocal performance. The adjustable parameters on a reverb unit allow you to control these reflections to simulate various acoustic environments.
“Delay is one or more echoes that have a more distinctly audible space between the initiation of the original sound and its reflection. There is a more distinct repetition of the original sound (partial words, musical phrases, etc.) and an eventual diminishing of volume over time. Delay is the effect you experience when you shout into a large canyon: your voice bounces back to you in diminishing waves.
“Once your mixer, signal processing gear, and power amp have shaped your audio signals, it’s your speakers’ job to turn those signals back into physical sound waves. Speakers reinterpret the signal by using the voltage from the amplifier to move their cones back and forth, producing the sound waves that reach the audience’s ears.
“Maybe it goes without saying, but speakers play a critical role in delivering quality sound to an audience, and it’s an area where quality gear can make a real difference.
“As is true for the power amp, the size of the venue you play will help you decide on the power handling (wattage) and size of the speakers needed. For example, smaller gigs, conferences, and lectures may require about 350-500 watts, while club bands, garage bands, and mobile DJs may need 500-1,000 watts, or even more, depending on the venues they perform in.
“In choosing PA speakers, the key trade offs to consider are portability versus performance. While full-range speaker cabinets that contain a woofer, mid-range driver, and tweeter are more portable and easier to set up, they typically won’t deliver the same performance as high-end speaker arrays.
Should I add a subwoofer?
“Subwoofers are the large speakers that handle the lowest bass frequencies. They are not integrated with full range enclosures both due to their size and the potential damage that can be caused to other components by their strong vibrations.
“Adding a subwoofer will of course make your PA less portable overall. Unless you opt for a powered subwoofer, you will also need a power amp capable of supplying the wattage required by power-hungry subs. Bands that play heavy rock, metal, reggae, hip-hop, and other styles that depend on powerful bass and drum sounds are most likely to want to include a subwoofer.
PA Monitor Speakers
“Musicians need to be able to hear themselves and other performers clearly to sound their best, which is why stage monitors are essential. While floor monitors can cause feedback and increase the risk of hearing damage, they are preferred over in-ear monitors by many performers because they are easier to use. These usually wedge-shaped speakers allow performers to hear themselves and play better because of it.
Other PA essentials
“We highly recommend getting a cable tester. If your system isn’t working correctly, a cable tester can save you hours of troubleshooting. We also recommend that once you find the defective cable, you immediately throw it away rather than putting it in a box to be accidentally used again someday, only to find that it (still) doesn’t work.
“You may also want a dB meter; many venues require that you don’t exceed a certain volume level, and a dB meter will let you accurately monitor your volume.
“Browse the complete selection of cable testers and dB meters at Musician’s Friend.
“If your PA system is not being installed, you’ll need some heavy-duty cases or bags to transport your gear. Well built, durable cases are essential to protect your valuable equipment.
“Speaker stands and brackets are another must-have accessory. Make sure to get sturdy, reliable nonskid stands that are strong enough to hold your gear securely. Check out the individual adjustability of each stand and make sure it will get your gear into an optimal position. Read specs to ensure the stands are rated to handle the weight of your speaker cabinets.
“Microphone stands are also an essential accessory for most PA rigs. You’ll find a broad range of mic stands designed to position mics for vocalists, instruments, and speaker cabinets. Choose designs with stable bases/tripods that will resist being easily knocked over during performance. Mic stands with adjustable booms allow more flexible placement.”