Tuesday, January 11, 2011

From mono to stereo to Dolby to . . .

Last Sunday night in my minivan I was listening to a radio show, the magnificent "The Big Broadcast" on WAMU, the local (in Washington, DC) National Public Radio affiliate. The program features recordings of dramatic, comedy, and musical programs from the "Golden Age" of radio, i.e., the 1930s, 1940s, and 1950s, when radio was the dominant and hugely popular broadcast media throughout the country, prior to the ascent of television, which began in the late 50s. Heard now, these programs, compared to contemporary radio, have a unique sonic and social ambiance, with an eerily different, dated quality to the voices, accents, and music--as well as a haunting innocence in the coverage of topics, even of the nightmare World War II with its domestic victory gardens and hail to the troops. Part of the reason for this difference is that these programs were broadcast over AM radio, on medium wave with its comparatively narrow bandwidth, which in itself limited the range and quality of sound that could be broadcast and heard.

One reason for the difference between the "old" sound and the "new" is that modern broadcasting--in radio (particularly in the FM or Frequency Modulation) stations, as well as television--is predominately in stereo (or stereophonic) and "high fidelity" quality, with a broader frequency rage (in bass and treble) and stronger, multivalent signal, resulting in greater clarity, definition, and accuracy in the voices, music, and sounds themselves . The difference is particularly noticeable in music, where there is a distinct sense of "presence" in the two-channel sound (putting the listener in the middle of the soundstream), with many primary instances from popular music, where there are distinct voices on both left and right channels (the Beatles being masters in this sort of sound manipulation.)

I remember clearly the transition from mono (monaural) to stereo (stereophonic) recordings, when the older single groove on the rotating disc could contain only a single audio signal. With the development of stereo, two channels, simultaneously etched into the single groove, carried signals from multiple microphone placement, to bring the listener the sense of being in the very center of the performance. I'll save for another blog entry my recollection of the mono to stereo transition in recordings, but what struck me the next day, while listening to music, was that there were distinctly different sounds coming out of the left and right channels of my modest car radio speaker--not exactly state-of-the-art in vehicular radio--but advanced enough to trigger an odd memory, as we say, of the bygone past:

As I've mentioned previously on VOAWorldMusic.com, much of my youthful energy and interest in junior high school, high school and college, was directed toward the discoveries of new musical experiences, and the attempt to perform in some of the idioms that most moved me. This interest of course led me to many record shops (see my first entry on the topic on VOAWorldMusic), and to listen to the music on both the leading classical radio station in Denver, my hometown, as well as the pop music stations. Through radio I discovered a progression of new musical worlds in many genres, and having been seduced (or perhaps more innocently for my age, bitten) by the excitement of STEREOPHONIC SOUND--I remember clearly my euphoria at purchasing my first stereo recording.

But even prior to that, the aforementioned local classical station undertook to present Denver's first stereophonic radio broadcast, in an ingenious experiment using the FM channel of the station (I've forgotten the call letters) for one channel and the AM channel (albeit with admittedly inferior sound capabilities) for the other. I set up two radios in the living room (one portable, the other in the massive console of our Magnavox record player/radio) and amidst the crackling, stifled audio of the AM channel and the superior voice of the FM channel, I experienced my first moment of stereo--or binaural, as it was also called briefly--music in the comfort and intimacy of my own living room.

Clunky as that experiment may now seem, this was a watershed experience in the broadcasting of the era--though admittedly quaint given current advances in sound recording and presentation.

I've forgotten the year when new broadcast technology enabled a single FM station (though never to my knowledge, an AM station) to introduce its listeners to, in effect, three-dimensional stereo sound--parallel in the auditory realm to the wonders (at the time) of 3-D movies (House of Wax remaining my defining recollection of the new media) in the cinema.

Warp speed ahead to last year, when we replaced our ancient but reliable 1987 Sony 15-inch analog TV with a Sony Bravia 22-inch flat screen unit, as well as a Sony "Home Theatre" system, which brought us not only the familiar sonic spread of stereo, but an initiation into the experience of the presumably five-channel "Dolby Sound" or "surround sound" of movie theatres in television programs (if they are presented in Dolby) and DVDs (most often with the Dolby theatrical experience.

Now where from here . . . in the years to come. . . ?

I'm told I should keep blog entries relatively brief. So I will reserve until later my recollections of the wonders of the progression from mono to stereo discs, with a brief but fascinating digression into the pioneering effort to improve the quality of early vinyl disc recordings by the venerable Westminster recording company in its superior Laboratory Series, which while initially monaural, eventually evolved to stereo recordings as well.

So enough for today. The beat goes on (as per the Sonny and Cher song) with much more to come as the year warms up.

Stay tuned.

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