Choosing The Right Sound System

By Andy McIntyre.

Sound reinforcement can quite often be the last thing to be budgeted in any building project. As a result, more often than not, cost restraints lead to compromises and in some cases sub-standard installations. This can be dangerous in a situation where the sound system also serves as the evacuation and warning system, and can be annoying when it doesn’t work the way you wanted it to, or you cannot understand a word that is being said. We have all been in a building and/or at an event where this is the case –  it can sound like someone trying to talk underwater. Usually this is due to low quality components (speakers, amplifiers, and/or microphones), poor design (wrong type of speaker, incorrectly placed speakers and so forth) and/or poor commissioning or operation. Here you will find an outline of some of the key features to look for when purchasing a sound system and the options you have.

The first and probably most important thing to look at is budget. The car analogy is often applicable here (do you want a BMW or a Hyundai?) There are many, many speaker boxes on the market place at every different price point you can think of, ranging from a $40 in-ceiling speaker up to a $40,000 concert line array cabinet. When trying to work out how much money you will need to spend you must consider what the system is primarily going to be used for. Some of the more commonly known uses include theatre, film, public address speaking, evacuation/emergency and concerts. During the federal governments Building The Education Revolution (BER) scheme many schools around the country received funding to build multipurpose halls. Most of these required installation of some sort of versatile theatre style sound system. Schools used a variety of approaches to get what they thought would be adequate. Some schools just purchased what the architect or builder specified, while others hired theatre consultants and some ran out of money before the sound systems were even thought about.

Using a BER multipurpose hall as an example, the following is one of the most successful methods of acquiring a sound system that meets your requirements.

Write down what the system is going to be used for, figure out what area you want covered within your venue (audience area, stage monitoring, dance floor and so on). Check if there are any issues with where you can mount the speakers and make sure you have adequate electricity to power your system (minium would be a 32 amp 3 phase). Once you have covered all this, it is then advisable to contact some local AV installers. Quite often you will find the local production hire company, which you may have used for the school plays or Christmas Carols, is also an installer, but make sure whoever you use has experience with installing the type of sound system you want. Call a meeting with each of them to discuss what you are looking for and they should be able to advise you of a few different options. The installers are usually well versed in the latest technologies and have experience working in theatres, concerts and on various installations. As a result, it can be quite cost saving to seek their advice rather than hiring a theatre consultant. As the installers are specialists, they will have a better understanding of your requirements than most builders or architects, plus the ability to service your system over future years. It is always good to get three options as they may come up with different ideas on how to reach your goals. You can also be sure that you will be happy with your own decision.

A sound system can be quite expensive, especially if you want something that will last, is easy to use and gives you great sound reproduction. Always try and be realistic in regards to costing, as there are a lot of hidden costs such as cables, racks, amplifiers, microphones, networking tools and of course the labour for the installation. Most of the installers are highly qualified tradespeople and will charge accordingly. In most multipurpose halls the cost of the cable and labour will start at around $30,000 and increase from there. Therefore a budget of around $100,000 should get you a good quality work-horse (a Holden Commodore if you will). Costs will differ depending on the size of the venue and what the system is going to be used for, but setting your budget is always a useful step for any sound system purchase. Communicating all aspects of your budget with the installers is also vital as they should be able to minimise your expenses and work within the figure you have set. It is a very competitive industry so generally you are assured of getting a good price, especially if they are aware that more than one party is bidding for the same job. Expect to pay around 20% off the recommended retail price for all the goods in your system (you will be able to find the pricing on the web) and around $90 an hour for labour.

When requesting a quotation, it is advisable to ask for other specific documentation as some installers may only present a costing schedule that is just model numbers and pricing on a spreadsheet. You have to be an industry professional to understand these, and as a result it can be unclear what you are getting or if all the bases are covered. A good installer will construct a simulation using 3D modelling of your venue showing the coverage and performance that the sound system is going to produce.

Some key acronyms used to describe the measurements shown in these drawings are SPL (Sound Pressure Level) and STI (Speech Transmission Index). SPL is how loud the system goes and shows where the speakers are delivering the sound. The objective is to have no more variance than plus or minus 3db which will ensure an even coverage throughout the room; usually a total of around 90 to100 decibels is ample. STI shows you how well speech will be reproduced and how clear your sound will be. Also, request all the documentation on all the equipment that is going to be provided. This will give you a good understanding of what you are purchasing and for what reason. There are also advantages in requesting the wiring diagrams and schematics to look at. These can give you a solid understanding of how everything goes together; plus it makes sure the installer has taken all the cabling and components into account.

Technology in sound reinforcement has moved very quickly over the years with the introduction of things such as lightweight/more powerful speakers, digital amplifiers, mixing consoles and more recently, networking and monitoring. An easy-to-use solution for most installations is networking your sound system. You can send information and commands through data cabling and connect some basic functions with your lights and projector to a wall controller. In a lot of situations this is ideal, as very little training is required to get the sound system up and running. With the push of a button you could set up your room in film configuration, as a lecture theatre or in concert mode. With a digital mixing console you can save the settings for every show, every rehearsal and every lecture; recalling it at a moment’s notice, saving time and reducing the likelihood of any human errors.

Purchasing a sound system can be a lot of fun and very rewarding especially if you take the time to research it and maximise your investment. Further down the track with an upgrade here and there, you could turn that Commodore into a Ferrari! As the common industry saying goes: “You’re only as good as your last gig”.

Andy McIntyre is CMI Music and Audios Pro Audio Product Manager. A highly skilled Acoustic designer and Audio Systems Engineer he has spent the last 5 years designing and commissioning large scale Sound Systems into Theatres, Churches, Schools and Concert Venues around Australia. Andy also lectures at RMIT and numerous other collages around the country on Concert sound design and acoustic theory.


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Education Technology Solutions
Education Technology Solutions has been created to inspire and encourage the use of technology in education. Through its content, Education Technology Solutions seeks to showcase cutting edge products and practices with a view to expanding the boundaries and raising the standards of education curricula. It introduces teachers and IT staff to the latest products, services and developments in education technology with a view to providing practical how-to guidance designed to facilitate the integration of those products and services into the school environment in the most productive and beneficial manner possible.

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