It’s important to note, infinite baffle does have some limitations. Since they don’t have an enclosure they will not take up as much room in the vehicle and can be mounted (in some applications) where they may not even be seen as at all. They do not have an enclosure that will change the way the woofer naturally sounds. Infinite baffle mounting is often considered the best overall sounding of all the examples we are going to talk about. With this type of mounting, the trunk is typically used as the “enclosure”.
Many vehicles have subwoofers mounted in the rear package tray infinite baffle right next to the full range speakers. The speakers have no enclosure and the speakers are mounted facing up in the package tray.
Another example of infinite baffle is how speakers are mounted in the rear package trays of most sedans. This can be a flat board with the woofers mounted to it and then attached to back of the seat of a sedan. It can be as simple as a board or mounting surface (called a “baffle”). The next sections will outline the most popular types of enclosures to help you make a selection that is right for your listening tastes.Īn infinite baffle is not necessarily an enclosure. Once you have determined the above conditions, you will then be able to make a choice that will get the best bass response.
Vas (L): This is the inverse of stiffness of the driver’s suspension, also known as compliance, while it is mounted in free air. The value of Qes is obtained via the formula:
A higher Qes indicates the driver is less electrically dampened, meaning it will oscillate at a greater amplitude over a narrower range of frequencies. Qes: A measure of the electrical “Q” or quality of the driver. As an example, below are phase and impedance plots of a Dayton Audio RS100-8 4″ midrange driver which has a resonant frequency of 92Hz: It is the point where the cone velocity peaks, impedance peaks, the cone phase reverses relative to the input signal and is generally the lower cut-off frequency of the driver.
Drivers oscillate due to the relationships between their mechanical and electrical properties.
Several important things happen around oscillation which define the enclosure design process.įs (Hz): This is the resonant frequency of a driver which is the frequency at which it most freely oscillates at. What the number actually describes is the range of frequencies for which the driver oscillates at, or the oscillation bandwidth. This number determines whether or not the driver(s) should be installed in a sealed or vented box. The first thing WinISD calculates is the Efficiency Bandwidth Product or EBP of the driver. It also gives frequency response, phase, SPL and other plots so you can see how changing various characteristics of the enclosure affects the performance.
It is a speaker design software which allows you to input custom drivers and it will tell you things like whether or not the enclosure should be vented, the shape of the vent, and the overall volume along with ideal dimensions. A tool I like to assist me for designing enclosures is called WinISD. The required volume is determined by the mechanical and electrical characteristics of the driver and whether or not the enclosure is ported or sealed. When it comes to speaker design, the lowest frequency driver determines the volume and therefore overall size of the enclosure.