Thursday

A Beginner’s Guide to Stage Sound – Part 1: The Equipment


The first article by our resident sound man-
Tim Burris: Lead singer of the local supergroup 'FailTrain'

Introduction


So your band has been working hard to build enough material to get out gigging. You’ve finally polished off a nice set list and booked a gig at the local bar. But the bar doesn’t have a PA or sound man, so you’ve got to acquire, set up, and configure your own PA. This is an opportunity to make or break your band’s reputation since all the practice in the world won’t improve the sound of feedback or a bad mix. Great bands have stumbled due to the lack of a quality sound system or trained sound man.
PA equipment can be a relatively simple set-up or a logistical nightmare. So to keep it simple, I am going to highlight 2 basic set-ups: An all-in-one PA and a traditional mixing board and Amplifier modular PA system. We will touch on 'powered' (also known as 'active') speakers in another article.
when you see speakers referenced in this article, we are referring to 'passive' speakers.
An all-in-one system will have your mixer, equalizer, effects, and amplifier in one convenient, easy to use, piece of hardware. You simply plug your microphones into the inputs, plug your speakers into the outputs, and voila, you’ve got sound. Well, it’s not exactly that easy, but that’s the general idea. A modular PA will require a lot more individual equipment, but it allows for versatility, flexibility, and growth.

Microphones


Before you get started you have to get all of your hardware. Let’s start with inputs. You will need vocal microphones, instrument microphones, and in some cases drum microphones (which we won’t discuss here). Not just any microphone makes a good vocal microphone.
For vocal microphones, you should start by finding a microphone that is “Dynamic”, and “Cardioid.” Dynamic refers to the fact that the microphone doesn’t require any external power and that the microphone responds well to varying volumes. Cardioid is another word for unidirectional which means that it will pick up sound that is directed primarily at the front of the microphone. This is an important thing to note when we get to talking about feedback. (A couple quality vocal microphones include the Shure SM-58 and EV N/D267A.)
Instrument microphones should be dynamic and either Super-cardioid or Ultra-cardioid. This will help prevent the microphone from boosting any other sounds from the stage. How often are your guitar cabinets within just a few feet of the drums? A good instrument mic will prevent sound from bleeding over, and give the sound man good control of what is being amplified. (A quality instrument microphone is the Shure SM-57 or the Sennheiser e609)

Microphone Cables

Microphones will need cables to plug into the mixer. Here, you should get low impedance XLR microphone cables with quality connectors. I cannot stress the importance of quality connectors enough. Many great musicians have had headaches during their sound checks due to bad cable connectors. A good rule of thumb is “You get what you pay for.” Another good rule of thumb - If the XLR connector doesn’t say ‘Neutrik’ on it, don’t’ buy it. (Yes, I’m biased)

Mixer Inputs

Next, the microphones will plug into a mixer. Each microphone will be designated a channel. It is important to note, at the mixer, which microphone belongs to which channel. I like to group my vocals next to each other (1-4), and then instruments (5-6), and then drums (7-12), labeling each on a piece of masking tape. These labels will greatly assist the sound tech while they are making adjustments during your performance.

Mixer Outputs (All-In-One Mixer/Amplifier)

All-in-one mixers include everything you need in one box. They are portable, easy to set-up, and generally less expensive than traditional modular set-ups. If your mixer is an all-in-one unit, then you simply need to connect your mixer/amplifier outputs to your speakers. In this case, you will have two groups of outputs: Mains and Monitors. For simplicity sake, we will have a “Mono” output and daisy-chain our mains and daisy-chain our monitors. When considering what kind of cable to use, consider both the output type of the Mixer/amplifier and the input type of the speaker. Some use 1/4 inch connectors, while newer models are using locking “Speakon” connectors. Make sure your cables are long enough to allow you to position your mixer in a safe, comfortable position while allowing for flexibility in positioning your main speaker and monitors.
Speakers should always be inspected to make sure that they are compatible with the impedance (4 Ohm or 8 Ohm) and output power (x Watts) of the amplifier. Incompatible hardware could result in damage to your speakers or amplifier.
*Please note that connectors should never be connected or disconnected while there is power running to the PA.

Traditional Modular Mixer Amplifier Set-ups

Modular set-ups require a lot more equipment than all-in-one units, but allow for greater flexibility and growth. To get a good sound quality, reduce feedback, and protect your equipment, the following hardware will be needed: Mixer, Effects Processor, 2 channel equalizer for mains and monitors, Crossover, Amplifier for mains, subs and Monitors.



Effects Processor

The mixer will send an auxillary signal to the effects processor. This is usually sent over a ¼ inch cable. The effects processor can modify the sound by adding chorus or reverb effects, then send them back to the mixer. Most mixers let you manipulate which channels get sent to the aux and which bypass it. So you may want effects on your vocal channels, but not your instruments.

Equalizer

The equalizer lets you help dial in your sound, and also eliminate any frequencies that are feeding back. Configuring the equalizer is a time consuming process that will require a lot of experimentation, but the benefits are well worth it. The mixer’s outbound signal will go to the equalizer. The equalizer will then send the modified signal to the crossover to be split.

Crossover

The crossover will separate your signal into High frequencies and Low frequencies. This is primarily used to send the low frequencies to their own subwoofers, while sending the high frequencies to speakers and horns. By separating the signals, you take a lot of strain off of your speakers and gain greater control over how each element of your sound is presented. If you don’t plan on using a subwoofer, a crossover is not necessary, but bear in mind that your mains will have to process a lot of sound. The crossover generally receives the signal from the equalizer and passes it to the amplifiers.

Amplifiers

The amplifiers will boost the “cold” signal into a powerful, amplified signal ready to go to the speakers. This is one of the most dangerous elements of the set-up, as misconfigured or mis-wired amplifiers can result in permanent damage to your equipment. Make sure your output impedance and wattage match what your speakers are capable of handling.

Speakers - Mains (FOH)

The most important speakers in your set-up will be your mains. This is what delivers your final mix to the audience. They are also referred to as FOH (Front of House) Speakers. A rule of thumb – Never place your FOH speakers behind your performers and their mics. This is a recipe for feedback.

Speakers - Monitors

These speakers are placed on the stage and aimed at the performers so that you can hear yourself. Many All-In-One PA systems will only allow for one monitor signal. This means that you get to create a single mix of instruments and vocals and play them back to the performers. More advanced set-ups will allow for separate monitor mixes. So the guitarists can have more guitar and singer can have more vocals.

Speakers – Subs

Most All-in-one units don’t’ allow for the additional of subwoofers without some creative engineering. So these will generally be used more with modular PA systems. They will produce your deep low sounds, and when used in coordination with a good crossover, will remove the low sounds from your main FOH speakers, giving them more clear and crisp highs.

More on Cables

You will need microphone cables, speaker cables, power cables, connectors to bridge equipment, and extension cords. It is important to inspect your cables regularly and take good care of them as a single cable can be the difference between a great sounding show and a night of headaches. In general, you get what you pay for, so if there’s one place to avoid the bargain shopping, it’s on your cables.

…In our next article we’ll talk about how to use this equipment together and configure it before a performance to help control and enhance your sound.

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