PA 101 Part-1: A Solid Foundation

TomCat

Here is the first part of a series on Basic PA-101.

This first part I decided to call “A solid Foundation”, and serves as an introduction only.

It is vital that any decisions regarding the purchase of a sound system be made on solid principles and foundations. A sound system is a major investment and the purchase of unsuitable equipment is an expensive and costly mistake.

Getting Going....

So you have been grinding that Axe now for four hours a day and feel you are now ready to hit the big bad world out there with your talent.

Problem: - You have no PA kit and there is no guarantee that the venue you are going to play in has one either.
So you Google....you ask questions etc, only to discover that the world of professional audio appears to be more scary than a Britney Spears Karaoke evening.

So...to start off, let’s get the basic terminology right. Strictly speaking the PA system we refer to here is actually called a Sound Reinforcement System. PA systems as such are usually associated with announcements in public spaces.

So what makes up a basic Sound Reinforcement System?
A typical sound reinforcement system will include the following:
1. Input sources
2. A multi channel mixer
3. Outboard processing equipment
4. Amplification
5. Loudspeakers
6. The cables that connects everything together.
I will endeavour to cover each of the above sections in more detail later, but for now lets look at each of these in brief.

Input sources:
Input sources can be divided into three basic categories as follows:
1. Microphones:
Microphones are by far the most common input devices in any sound system. Microphones are used to pick up the sound of just about any kind of acoustic source there is out there.
Microphones range from vocal microphones optimises for singers, to instrument microphones for all types of instruments.
Microphones also have the lowest electrical output level of all source types so special attention is given to microphone signals to ensure that the best possible audio quality is maintained.
Microphones can also be either connected via a microphone cable or be wireless (more on this in another article)
2. Instruments:
Different instrument has vastly differing signal levels with electric guitars having the lowest levels and keyboards and acoustic guitars with preamps the highest.
3. Line Level Devices:
These include devices such as I-Pods and CD Players.

Multi Channel Mixer
The mixer is probably going to be the most important piece of equipment in your system setup as the quality and features of the mixer will have the biggest influence on the quality, versatility and adaptability of you sound system.
There are many different types of mixers available on the market these days. Many are good, but as with anything, there are also a few bad eggs out there.
The role of the mixer is threefold.
1. Preamplifier to amplify the low level signals of microphones and instruments to a higher level suitable for driving power amplifiers and outboard equipment.
2. Combine or mix different input sources to provide a coherent output to the loudspeakers
3. Route combinations of input sources to different outputs such as the main loudspeakers, stage monitor loudspeakers and outboard equipment.

Outboard Processing Equipment
Outboard Processing Equipment includes items such as effects processors for reverb and delay effects, dynamic processors such as compressors and gates and equalization devices such as parametric and graphic equalizers.
These processors allow us to change the character, tone or dynamics of our input sources to better blend these to provide a more musical result.

Amplification
The mixer itself cannot provide enough power to directly drive the loudspeakers (except when the power amplifier is included as part of the mixer package).
Power amplifiers therefore increase the power of our mixed signals sufficiently to drive the loudspeakers.
The power amplifiers can also be included in the loudspeaker package as well.

Loudspeakers
The role of the loudspeakers is to project the amplified sound from the power amplifiers into the audience.
Loudspeaker for sound reinforcement fall into two main categories, namely Front-of-House (FOH) loudspeakers and stage monitor, or what is also called foldback loudspeakers.

Cabling
Cabling is a vital and often overlooked part of the sound reinforcement system. They are the arteries and veins of your sound system and poor cables will always let you down at the most inappropriate time.

Selecting a Sound Reinforcement System
Now that we have covered some basic introductions regarding the parts of the system, lets look at how one goes about purchasing a system for your needs.

Before you consider anything, there are a few questions that need some answers.
These are:
1. Are you only a solo artist or is there a band involved? This determines how many inputs and outputs your mixer will need.
2. What are the typical venues you will be playing in? This determines roughly how large and how many loudspeakers you will need to be to fill the venue.
3. What music style do you play? Folk / Acoustic styles will require much less horsepower of your system than Pop / Rock / Metal.
4. How will you transport your system? Is it limited to the boot of your car or is a trailer required?
5. How much money are you prepared to spend?

This introduction does not answer these questions, but the next few articles will, as well as other issues regarding sound systems……..read on…..

Dirk

Thanx for the brilliant and informative post Tom. Being mostly involved in the music part of the business, I know very little of the sound part. You answered a whole lot of questions for me..

Looking forward to the rest (You should start charging for info like this? )

Lethe

sweet

Bob-Dubery

Fab! Karma for Tom.

[deleted]

Thanks Tom.

Great read, many thanks... :applause:

TomCat

Thanks guys.....Part-2 coming up soon...... ?

TomCat

And to those who sent me Karma (Bob...and others)....deeply appreciated ? ?

Riaan-Combrink

Just got to this thread now.

Very well done Tom. Comprehensive and easy to follow. Great. Have another karma, Sir!

PS: I'm hoping we'll get to some discussion of brand names in some of the more detailled posts - to guide the guys who want to buy or upgrade a PA (oops - SRS). Unless the moderators are of the view that this may promote covert advertising or lead into a slagging of potential sponsors?

Great post!

TomCat

Riaan C wrote: PS: I'm hoping we'll get to some discussion of brand names in some of the more detailled posts - to guide the guys who want to buy or upgrade a PA (oops - SRS). Unless the moderators are of the view that this may promote covert advertising or lead into a slagging of potential sponsors?

Great post!

HHMMMMMMMM......!!!. Yup. This is a difficult one. Lets see what Alan thinks.

I know that I am opening myself up to abuse here but guys can PM me about upgrades, kit opinion etc if they want to.

Riaan-Combrink

TomCat wrote: [I know that I am opening myself up to abuse here but guys can PM me about upgrades, kit opinion etc if they want to.

Yes you are, and you can bet I will! ?

Maybe its the safest route to go, though.

TomCat

LOL......Bring it on......

Squonk

Good stuff Tom

If I wore a hat, it would be lifted off my head ?

AlanRatcliffe

TomCat wrote:
Riaan C wrote: PS: I'm hoping we'll get to some discussion of brand names in some of the more detailled posts - to guide the guys who want to buy or upgrade a PA (oops - SRS). Unless the moderators are of the view that this may promote covert advertising or lead into a slagging of potential sponsors?
HHMMMMMMMM......!!!. Yup. This is a difficult one. Lets see what Alan thinks.

Gear discussion is one of the things we're here for guys. As long as there are no direct solictations for sales of new products or services. You want direct promotion, approach us for our (very reasonable) ad rates. Also no out-and-out shilling for products by members with affiliations - I have given up or turned down endorsements and agencies from a number of prestigious brands so that I can be neutral, so I don't appreciate it when others with vested interests aren't.

Unlike some, I'm of the opinion that slagging is OK where slagging is due (view my stance on modern Gibsons for proof). Even the best manufacturers have had some lemons through the years, and we are all entitled to our opinions and to air them. Just be prepared to accept that others may have opinions to the contrary and are also entitled to air them in response. Also, don't get nasty when criticizing/defending a product.

Having said all that, Crown/Amcron amps and EV speakers are the best in my personal experience... ?

TomCat

Thanks Alan

OK Lets do it.....!!!. I am not affiliated to any product or brands so we are safe here.

LouisNeilson

Thanks a lot for this ou!
Been looking for something like this.

Keep up the good work!

Tonedef

I am, ahem, monitoring this thread! Learning lots! +1