Earlier, in the seventies and eighties of the last century, it was believed that the more speakers in the column, the better. The modern approach to organizing the sound of rooms is somewhat different, the spread of the Dolby Surround system with a separate subwoofer has somewhat shaken the confidence in the optimal sound of speakers with several speakers, but they still have quite a lot of fans.
The question of what speakers should be for speakers has been worrying developers and technologists since the moment when these electromechanical emitters entered everyday life. There is a certain contradiction in the requirements for the diffuser. On the one hand, for high-quality reproduction of the lower, bass spectrum, it must have a sufficiently large size and a massive magnetic coil, most of the power is spent on “bass buildup”. On the other hand, high frequencies require maximum lightness of the oscillatory system and minimum inertia.
Ultimately the developersof acoustic accessories came to a logical decision: to place cooperating low-frequency speakers and so-called “tweeters” in the column. True, in this case a "dip" was formed in the middle of the spectrum, but this problem is eliminated by adding a third loudspeaker operating in this range.
The frequency response is then leveled over the entire audible band. The woofer can work without additional filters, but in order to reduce the load on it and prolong the durability, it is equipped with a series-connected inductor that does not pass medium and high waves. The mid-range speaker is also spared the need to rattle on the bass and treble components. To do this, a coil and a capacitor are included in the same line with it. As for the “tweeter”, only the band intended for it from about 3 kHz and above can be fed there, for this, a capacitance is included in series with this speaker.
Modern woofer is a complex electromechanical device. The diffuser is quite large. To ensure it for a long time, materials are needed that can withstand elastic deformations and retain their properties. Usually, the edge of the emitter is connected to the diffuser holder with a semicircular rubber ring.
The working stroke, which is a few millimeters, must have a clear trajectory, otherwise the edges of the coil will become "overwritten" by the central magnet. She isprovided with a centering washer, usually made of perforated fabric impregnated with a binder polymer, with annular shirring.
The woofer is a high-tech device, all the latest achievements in the field of polymer production are used in its design. The diffuser must be rigid, then the force from the coil will be transmitted to its entire surface almost instantly, and light, so that the acceleration characteristic has the shortest possible delay time. However, in most of the most expensive and high-quality loudspeakers, oddly enough, despite all the achievements of modern technology, paper is used, as in the first speaker, which was invented in 1925 by the Americans Rice and Kellogg.
The woofer has become an integral part of the design of any quality speaker system.
