27/01/2009- Subwoofer Enclosure Types and Loading Methods
For many years, 12 volt guys have been misunderstood, mistaught or tend to make up their own beliefs on what type of subwoofer enclosures are better for what type results.  The truth is that there are several types of enclosures, each with their own signature trait.  To say that one type of enclosure is better for Rap, Rock, Jazz or Country music is just plain dumb.  I’ve heard “sealed” boxes that are way too “boomy” (underdamped) that sound terrible, even though these boxes are thought to be the Audiophile’s choice.

27/01/2009- Measuring Transfer Function, Boundary Loading & Soundwaves
Ever wonder why a box can sound great in a car but crappy in your garage or even in a car audio shop?  The reason why subwoofers sound louder and better in vehicle is due to Transfer Function.  TF is a phenomenon caused by vehicle resonances, boundary loading, reflections and absorptions.  Virtually every vehicle, room or chamber has signature TF.  Obviously if you play a 15” sub in an open field, it will not be nearly as loud as in a much smaller vehicle, but TF also “amplifies” the output at a certain rate beginning at a certain frequency per vehicle.

27/01/2009- A-Periodic Membranes
A-periodic membranes are not a new concept. Though rarely seen in the mobile audio industry, they have actually been around for decades. Dynaco was the first known company to introduce an enclosure alignment of this sort. Dynaco used a damping material in the vent which differs from the applications used today in the automobile environment.

27/01/2009- Solving the
There are a few primary problems that are encountered when we install subwoofer enclosures into a sedan type vehicle with a trunk. The most obvious problem is the reduced amount of bass in the main listening cabin. The next possible problem is that there is more bass with the trunk open than when closed. A third problem is the excessive rattling of the trunk body panels.  Proper damping will greatly reduce the vibrating body panels and yield slightly higher SPL in the vehicle, but will not resolve the other issues inherent with sedans.