Subwoofers_Dubois

Senior Project 2014
MTI News.org

Transcript

1. Subwoofers and their History Tyler Dubois AUTO 2013-2014
3. History • Dr. Harry Olsen was also a major contributor to the design of audio systems that we have today. In the 1930's/40's, he was the first to assert that speakers are in need of a back as well as a front, as otherwise sound waves from the back will interfere with the front ones. He also designed the passive radiator, which was design meant to be a substitute for the vent - a system that had a great number of faults at the time. The vent design needed a large duct in order to avoid wind noises, which often meant the duct was larger than the vent itself. Olsen, instead used a diaphragm with suspension whose mass was equal to that of the air column in the vent, thus it was much smaller and much more efficient than the other design. • Jensen's James Novak, a highly gifted research engineer and mathematician, was to come up with the bass reflex design. Through his knowledge as a mathematician and experience as an engineer, he was able to create and synthesize ideas for what today is known as the closed, vented and passive speaker systems.
5. How it works • How a subwoofer works-Simply put, subwoofers move air. The subwoofer’s cone is large and has more excursion (back and forth movement) compared to other speakers so it moves more air. The subwoofer experience is not about being "loud." Rather it is about moving enough air to produce low frequencies so that listeners can hear and ‘feel’ the complete sound experience.
7. Powered • • Powered Subwoofers - Also called amplified subwoofers, these models include a subwoofer driver, the enclosure, and a built-in amplifier. The built-in amplifier is matched to the subwoofer, and the enclosure and internal volume are optimized for the subwoofer driver’s performance characteristics. Powered subwoofers typically accept speaker level or preamp level RCA inputs, making them a great addition to an OEM or aftermarket audio system. Powered subwoofers typically include all the necessary mounting hardware, but may require power wiring and audio signal inputs to complete the installation. • Past Subwoofers may also include Home audio and Marine audio. • Anyone who is a car audio fan or who has come by it in passing will know what a subwoofer is. Subwoofers are used to generate that intense and deep feeling of bass, which is normally out of the range of most average speakers. Subwoofers are used not only in car audio, but in home stereos too to give ultimate bass within a small area, such as a room or car. • Although subwoofers may seem simple enough, there are in fact not quite as simple as they seem. Over the years, they have been researched, tested and developed in order to get the best sound out of them as possible. However, like any product there are varying degrees of quality of subwoofers as well as types, which are suited to different requirements and situations.