A pair of late 1970's Magnepan MG-1 speakers. The speaker on the right has had its cover removed, revealing the planar drivers. This is a sheet of Mylar with a larger region of heavier gauge wire glued on to form the bass/midrange area and a smaller area of finer wire producing the treble. The Mylar sheet is tensioned a few millimeters above matching rows of permanent magnets so that the whole sheet vibrates like a drum skin when current from an amplifier is passed. The large surface area means the sheet is well damped by the air it moves. Being very light the sheet can stop and start noticeably quickly. This characteristic combined with the lack of chesty colouration caused by a speaker box is what makes the addictively realistic Magnepan sound. Later and more expensive models also use a true ribbon tweeter to extend the treble range. These units are renowned for their speed, accuracy and complete lack of "spit and sizzle". There are a couple of minor drawbacks: They are large; approximately the size and shape of a smallish interior door and to produce enough bass room placement is very important due to the motion of the mylar sheet suffering cancellation by reflected sound waves. People who love these speakers but are forced to adopt disadvantageous room positioning may resort to using a high quality sub-woofer.