Today's subwoofers most commonly range in size from 8 to 21 inches, but there are specialty applications where units as large as 60 inches in size and as small as 4" in size are used. The considerations when selecting specialty units are the enclosure, permitted distortion, desired frequency and pressure level of the provided sound. Most commonly used bass subwoofers are 10, 12, 15 and 18 inch units. As an example of the use of small subwoofers, one has only to look at the desktop speakers tied into computers, and on the other end of the spectrum we have the show style units that keep us hopping to the beat.As a result of the nature of the lower frequencies that produce the bass sound, the conversion of electrical energy into sound energy is terribly inefficient and hence the need for higher power output for subwoofers.
The internal pressures exerted on the enclosures by the operation of subwoofers, require most subwoofer cabinets to be constructed of durable, rigid materials with additional structural bracing added in to assist in the distribution of internal pressures. Materials such as MDF (medium density fiberboard), OSB (oriented strand board), plywood, aluminum and fiberglass are most frequently used.as the cabinet material In most vehicular applications, we use hardwoods due to their durability, adaptability and ease of installation.There are several considerations in the design of woofers, such as frequency response, range of pitch and sound pressure. Frequency response is the range of musical tones or frequencies that a speaker can reproduce. The common use subwoofers that we purchase as either part of a home surround systems or considered an add-on, operate in the range of 20-200 Hz, a Hz or hertz being a unit of frequency measure, much in the same way that a volt or watt is a unit of electrical measure.
The subwoofer systems that are used at concerts generally operate below the 100 Hz frequency range, while THX systems operate below 80Hz.Range of pitch is determined by the size and construction of the enclosure and the installed drivers. The pitch is also measured in Hz (hertz) and in general, falls in the range of 23-350 Hz. As mentioned earlier, internal pressure has an effect on distortion and on design consideration to try and minimize distortion to its lowest level.As we have seen, designing and choosing the right subwoofer for your specific application can present some challenges. By having a good overview of why design is essential we should be equipped to select the appropriate device for our listening pleasure.
Cyber Acoustics Subwoofer Satellite System (CA-3602a)