OTHER TECH

35. Audio Cassette Introduced in 1962 by Philips as a dictation medium, the audio cassette seemed unpromising as a carrier of high-fidelity stereo sound. But development of a consumer version of the Dolby noise reduction system, high-performance recorders such as the Advent 201, and the Walkman eventually made it a hugely successful alternative to LPs.

36. CD and DVD Recorders As soon as they got over their initial excitement about CDs, people started asking when they would be able to record on them. It took a while (about 6 years), but recordable CDs, and lately DVDs, have since become a part of everyday life.

37. Stereo Headphones Koss's Stereophones (1961) were the first stereo headsets, advancing the cause of personal listening and setting the stage for a portable-music explosion in the form of the Walkman and later the iPod.

38. Stereo FM The initiation of mono-compatible multiplex FM broadcasting in 1961 cemented stereo's place in music recording and distribution.

39. Satellite Radio Launched in 2001 (XM) and 2002 (Sirius), digital satellite radio created the kind of programming diversity in radio that we've long been accustomed to in TV. (And with practically no comercials.)

40. Dome Tweeter In 1958 (it was a big year), Acoustic Research introduced its AR-3, the first speaker to use a dome tweeter. Unlike a cone, a dome could be made small enough for good high-frequency dispersion while retaining a voice coil large enough for adequate power-handling.

41. DSP Digital signal processing is central to all digital audio and video formats, from CD and Dolby Digital to DVD and HDTV.

42. Graphic Equalizers Advent and Soundcraftsmen introduced the first graphic equalizers designed primarily for home use around 1970, giving audiophiles a convenient and flexible means for adjusting frequency response. Other companies followed suit, and EQs have been in wide use ever since, either as separate components or built into receivers.