HDTV Magazine
Welcome, Anonymous  •  Sign In  •  Register  •  Help

Like many, I love (most) old movies. And again, like many, I have accumulated a significant collection of classics – most on VCR’s and on the old RCA CED video disc format (RIP). With the advent of HDTV and advanced film restoration technologies, the BD and DVD versions of these movies are – for the most part – spectacular. However, the one generally disappointing aspect that mars the total HD experience of these productions is the disappointing sound quality. This is especially true with the beautifully (video) restored versions of the 1950’s – 60’s musical classics such as, “Singin’ in the Rain” and “There’s No Business Like Show Business” and other such movie musicals of this era.

Of course, one should not expect six-channel sound or even Hi-Hi, but one would hope for something at least as good as a vintage 50’s LP. But that’s not what one gets. Instead, what vibrates the air is a woefully compressed, somewhat noisy mess. No amount of jiggling of the thousands of handles on my Super Sony receiver helps much. Garbage in-garbage out. Why doesn’t the audio quality of these mid-20th century classic restorations match the superb video quality?” After talking with some film restoration people along with research from Academy and SMPTE documentation, the answer becomes clear – or at least clearer:

Virtually all film restoration starts with a (hopefully) properly stored copy of either a release print or, with luck, the originally edited negative(s). Very seldom were the unedited negative elements or the final mixed optical sound tracks saved. Production sound technology and techniques were essentially unchanged from the early 1930’s until the early 1950’s when sound origination and editing had switched to magnetic media. Except for a brief period of magnetic multichannel release prints for major market theaters in the 1960’s, virtually all prints distributed employed monaural optical formats. This was the case until the advent of “Dolby Digital” and the establishment of the large, modern movie theater multiplexes in the 1990’s. Of course, sound production technology had improved both optically and electrically – taking advantage of improved optics, film emulsions, bulbs, sensors, microphone and amplifier circuitry – coping broadcast and recording technological improvements.

As television became increasingly competitive in the ‘50s, there was little economic incentive for medium and small market movie theaters to upgrade to magnetic sound reproduction equipment, and it was simply too expensive for distributors to support both optical and magnetic release print distribution. Not until the introduction of Dolby noise reduction technology applied to the optical format (in the application of “Dolby Stereo”) in the 1970’s, did optical sound tracks approach the quality of magnetic formats. But alas, by then, the era of movie musicals had long passed.

Restoring the old optical tracks usually consists of physical cleaning and the application of some analog ”pop” and “hiss” filtering. In extreme cases, the audio analog signal is digitized and reconstructed. This process can restore even the most damaged tracks, but there are definite downsides to digital sound restoration, especially for music information. Many times such digital signal processing introduces undesired artifacts, such as phase anomalies and sibilant hype in addition to a loss of high frequencies. And the process is time consuming and expensive. More recent film sound restoration technologies have achieved superior results by actually digitizing the sound track optical patterns as opposed to digitizing the detected optical audio signal itself. With these techniques restoration and enhancement can occur simultaneously with virtually no artifacts and with less expense. But, it is not clear whether the economics of film restoration will support the expense of audio re-restoration and enhancement.

However, now that some of Alexander Graham Bell’s original optical sound recordings (predating those of Edison’s) have been recently restored to audible recognition, perhaps the means does exist to restore the full fidelity of those original movie musical classics.

Ed

Posted by Ed Milbourn, May 18, 2012 7:26 AM

More from Ed Milbourn

» - Currently Reading

About Ed Milbourn

After graduating from Purdue University with degrees in Electrical Engineering and Industrial Education in 1961 and 1963 respectively, Ed Milbourn joined the RCA Home Entertainment Division in 1963. During his thirty-eight year career with RCA (later GE and Thomson multimedia), Mr. Milbourn held the positions of Field Service Engineer, Manager of Technical Training and Manager of Sales Training. In 1987, he joined Thomson's Product Management group as Manager of Advanced Television Systems Planning, with responsibilities including Digital Television and High Definition Television Product Management. Mr. Milbourn retired from Thomson multimedia in December 2001, and is now a Consumer Electronics Industry consultant.