Anyone who is a fan of car audio or who has known it in passing will know what a subwoofer is. Subwoofers are used to generate that deep, rich feeling of bass, which is normally out of reach for most average loudspeakers. Subwoofers are used not only in car audio but also in home stereos to deliver the best bass within a small area such as a room or car.

Although subwoofers may seem quite simple, they are actually not as simple as they seem. Over the years they have been researched, tested and developed to get the best sound possible. However, like any product, there are various quality grades of subwoofers, as well as types, to suit different requirements and situations.

The first company to introduce decent subwoofers was Acoustic Research (AR), which in 1954 introduced the AR-1W, a system that could extend its bass down to 20 Hz without any equalization aids and was literally a woofer efficiently encased in an enclosure. The AR-1W was second to none in design for years and, in fact, remains highly influential in modern subwoofer design for its use of the acoustic suspension principle. The AR-1W was a compact subwoofer that could easily be installed on a bookshelf two at a time, unlike the monstrous-sized enclosed speakers previously marketed.

Dr. Harry Olsen was also one of the major contributors to the design of the audio systems we have today. In the 1930s and 1940s, he was the first to state that loudspeakers needed a back as well as a front, otherwise sound waves from the back would interfere with the front ones. He also designed the passive radiator, the design of which was intended to be a substitute for ventilation, a system that had a large number of flaws at the time. The vent design required a large duct to keep out wind noise, which often meant the duct was larger than the vent itself. Olsen instead used a suspension diaphragm whose mass was equal to that of the air column in the vent, making it much smaller and much more efficient than the other design.

James Novak of Jensen, a very talented mathematician and research engineer, was to come up with the bass reflex design. Through his knowledge as a mathematician and his experience as an engineer, he was able to create and synthesize ideas for what are now known as closed, ventilated, passive loudspeaker systems.

Though considered an essential component today, bass extension was still a relative luxury in the 1950s and 1970s. The movie businesses were the primary stakeholders in bass extension, which was first used commercially for the great success of 1977, Star Wars.

In the last century, these master engineers and mathematicians have probably been the most influential in the excellent acoustics available in today’s car audio systems and home stereos.