Enclosure Considerations 102

Filed under: Car Audio > Processors & Crossovers



Pete Kulicki is a guest writer that will be providing articles on his specialty, enclosures. Stop by and check out Pete's own site, Hexibase, for tons of great info on audio in general and enclosure designing.



As redundant as this may sound, the key to successful project resolution is proper planning. In this article, I’d like to outline and further expand on some basic enclosure design principles, several of which I’ve touched upon in prior editorials. Whether you prepare to assemble your first enclosure or measure out your five hundredth trunk, there’s always some groundwork between the initial conception and the first cut of wood.

Step One: Establish the objective.

What’s there to establish? You’ve set out to build a subwoofer so obviously, your objective must be to achieve low frequency response, right? Well, hang on. Obviously, tonality can be categorized into many forms; therefore, low frequency response isn’t so much an objective as it is a further divisible category. Our prime concern here is to characterize the end result, whether it’s a flat response extension down to a certain frequency or narrow-band efficiency.

Step Two: Explore suitable design options.

The success of your project is determined by how closely the end result follows your established objective. The key emphasis of this step is to explore the feasibility and the effectiveness of any proposed enclosure style. Some deciding factors to keep in mind here include the environmental and dimensional cabin properties that help characterize your interior acoustics. Don’t forget; you’re designing for an awkwardly-shaped chamber that is your cabin, not for an infinite environment with an omni-directional damping pattern (as most design software would have you believe). It’s also important not to get stuck on groundless ideas. Quite often, someone will randomly decide on a given alignment, regardless of how inconsistent it may be with its intended loading environment; they just want it because it’s “cool” or “different” – not very smart. A speed boat may be cool and different but, if you’re traveling down an interstate, you’re better off taking a car.

Step Three: Select your gear.

This step is, by far, the most common to be taken out of order. Clearly, you can’t know what electro-mechanical parameters will best suit your objective until you have a good insight into the loading characteristics of your cabin and have outlined some viable alignment solutions in the prior step. Yet we’ve all seen folks who begin the whole process with a set of arbitrarily preconceived parameters like woofer size, just trying to work everything around that one constant like an architect trying to build a house around a door knob. Don’t let the tail wag the dog. Selecting your gear (namely your woofers and amplifiers) should actually be one of the last things on the “to do” list.

Step Four: Design and assembly.

Now that we’ve filled in all the blanks, it’s time to take the theoretical design from step number two and apply it to the electro-mechanical parameters of the equipment that we’ve selected in step number three. Note that what works in theory doesn’t always work in practice so you may very well find yourself looping back a step or two in search of a more practical or effective solution. In that regard, you can think of the physical assembly as the finalizing operation, signifying a successful design process.