The Art & Science of Audio & Video

Design Principles: Part I (of many)

An insight into speaker selection.

People approach me all the time wanting advice before purchasing a new system. Whether it is a home theater, car audio system, two-channel stereo or a pro system for a church, club or other large public facility the same basic principles apply. As you can imagine this is not an easy question to answer. Before making any decisions we need to do a little fact gathering. Such as what will the system be used for and what kind of budget are we working with. A little careful planning and consciously working towards a properly matched system will yield much better results than just selecting equipment at random. Most people are surprised to learn that purchasing the most expensive components you can find rarely yields the best results.

The first design element to be determined should always be your speakers. Choosing the proper speaker can require a lot of research in some cases and in others it can be decided upon using basic criteria such as aesthetics or installation method. Many variables must be considered to find the speaker that will best serve the needs of the end user. Below is a list of things you should ask yourself when selecting a speaker.

1. What purpose does the system serve?
· Is it strictly for public address, therefore only needs to adequately cover the vocal range?
· Is it for theatrical performances?
· Is it for sound reinforcement? If so for what kind of program material, simply multimedia playback, small jazz ensembles, House DJs or hard rock and metal bands?
· Is this for a movie theater?
· Car audio; casual listening or competition system?
· Car audio; is it a luxury sedan with little interior noise in the cabin or a high performance sports car with loud exhaust and lots of road noise?
· Home theater; is this a dedicated theater room or a family room for everyday use?
· Home theater; what is a higher priority aesthetics or fidelity?

The list could go on and on with virtually and infinite number of specific questions that all weigh in on your decision making process. The selection process for a well-designed professional sound system intended for a theater, auditorium or sports facility is generally the most difficult. The reason is because you are dealing with an acoustic environment that may or may not be flattering to your new sound system. Don’t get me wrong the same goes for residential environments as well as mobile audio systems too. However the variation in acoustics from one residential setting to another, or from one automobile to another, seldom vary to the extremes that you experience in large venues. Providing solutions for the acoustic anomalies in these environments typically proves to be much easier as well. There is a software program available to professionals, which allows an engineer to construct a virtual model of the acoustical environment in which the new system will be installed. Then using a massive database of acoustical data accumulated on hundreds of speakers they can place a given speaker within that acoustical space and see how it will respond to its’ environment. This obviously eliminates a lot of guesswork and has revolutionized the engineer’s ability to better match speakers to the particular space in which they will be used.

So why must we choose our speakers first? Until you determine the speaker to be used you cannot possibly know what kind of power requirements you will have. So once you know what kind and how many speakers you will have you can accurately determine the number and size of amplifiers needed to drive them. Then you are able to begin making decisions concerning your processing needs. What kind of processing requirements you will have, do you need extensive programming capabilities, and how many inputs and outputs do you need to feed your amps? Are you going to need a graphical user interface for the end user and so on and so forth?

Things to consider are the area to be covered and the SPL desired throughout the room and/or facility. This is going to determine not only the type and quantity of speakers but the placement as well. There is not enough room in a single blog or really an entire web site for that matter to adequately cover all of the decisions to be made when choosing the right speakers. So let’s look at a truncated list just to highlight a few.

· 2-way verses 3-way cabinets (or even 2/3 way systems consisting of all individual enclosures).
· 10”, 12” or 15” low frequency driver if not multiple drivers in each.
· Passive vs. Active
· Are subwoofers needed, if so size and quantity?
· Cabinet design, concentric, horn loaded, bass reflex, sealed, transmission line, etc.
· Multiple cabinet cluster, distributed speakers or line array?

I think you see my point.

Veteran designers and consultants can assess a room and have things narrowed down to just a couple of options within minutes. This of course just comes from experience, this guy has probably been in hundreds of rooms just like this and knows what worked before. However there are always new products, new technology and new breakthroughs in research and development to keep everybody on their toes.

by Jason Levert


March 16, 2008 - Posted by | Class: E=MC2(+/-3db) | , , , , , , , , , , ,

1 Comment »

  1. […] Kimberly Quang wrote an interesting post today onHere’s a quick excerptWhether it is a home theater, car audio system, two-channel stereo or a pro system for a church, club or other large public facility the same basic principles apply. As you can imagine this is […] […]

    Pingback by Design Principles: Part I (of many) | March 16, 2008 | Reply

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