Film buffs love watching classic films on DVD. Not only do these films look better than ever on DVD, but they sound better than ever, as well. New editions of movies "remastered in 5.1" appear all the time, but the average viewer may not be aware of the work necessary to make a film originally mixed years ago and make it sound fresh in the home theater environment.

In the 1980's, Chace Productions pioneered the conversion of older mono films into stereo with Chace Surround Stereo. The latest incarnation of this process is Chace Digital Stereo, designed to create 5.1 channel mixes. This technology has brought Chace plenty of remastering work in recent years. Titles as diverse as The Bridge On The River Kwai, Easy Rider, Hellraiser, The Muppet Movie and This Is Spinal Tap have recently passed through the doors of Chace's Burbank, California facilities on the way to DVD release.

James Young works in restoration and remastering at Chace Productions. Young began at Chace in 1990 as a "stereo programmer," creating directional effects for the sound tracks of a number of Turner library titles. In 1992, he started Chace"s restoration department, cleaning up and refurbishing audio tracks with digital tools such as Sonic Solutions" NoNoise. Young"s sonic skills have been utilized in reissues such as Gone With the Wind and The Wizard of Oz. Recently, Young took on the king of cult movies, The Rocky Horror Picture Show, creating a new 5.1 mix for DVD release. We asked Young to guide us through the process of remastering a film sound track, and to give some examples from his experience on The Rocky Horror Picture Show.

The first " and hardest " step, Young explains, "is the cataloging, and the tracking down of elements." The age of the film plays a big part in the availability and quality of sound elements. "The old tracks were mastered to optical," Young explains, "but since the mid-50's, a lot of tracks were mastered to mag." Mag is shorthand for 35 millimeter magnetic film, which is preferred as a source because it provides higher fidelity sound reproduction. With a mag available, "the only problems you have are bad transfers over time, or physical wear and tear on the element itself," Young says.

Finding all these pieces of the sound puzzle can be daunting not only because of deterioration, but also because the need for such materials was not originally anticipated. Restoring the soundtracks to classics such as North By Northwest and Gone With The Wind has required a bit of detective work, and sometimes a little luck. North By Northwest had to be reconstructed from several sources, including music tracks that had become stuck together and an airline version that had 30 minutes removed. "One of the key elements that we found for Gone With The Wind was because [of] a music editor who had been with MGM for years," Young remembers. "At one point, when there was a vault being moved, like in the '60s, they found this element for Gone With The Wind that they were instructed to throw away. And he thought to himself, "Oh my God, this is way too valuable to throw away!" So he kind of hid it in the vault and 30 years later, it was the best soundtrack available."

Remastering in stereo is made easier when sound track elements can be taken from discrete, non-composite sources. Many films are archived with three sound track "stems," one each for the dialog, the music and the sound effects " "DME" for short " and each stem may have multiple tracks. Sometimes, Young points out, "we are actually faced with evaluating three, or four, or five, or six different versions, or six different copies or formats of a film. [On] some films, there'll be mono, and two-channel stereo, and four-channel stereo elements, or four-channel and six-channel stereo. And that's the first step, getting together everything we can, evaluating it, finding the best stuff."

"Specifically, with Rocky Horror Picture Show," Young says, "we were working from the original mono mag master. It was a 35 millimeter three-track " Dialog, Music, and Effects." The film was originally released in 1975, mixed in mono by Bill Rowe. As a musical, however, an effective 5.1 mix of The Rocky Horror Picture Show called for more than just a mono music track. "We also had access to the original 2-inch, 24-track music multi-tracks," Young explains. "It's the best scenario for integrating a stereo music source, when you have a DME, because then you can just swap [stereo] music for [mono] music and still have your dialog and your effects from your original master."

With the best elements for a project chosen, the next step is to perform any necessary restoration. "In restoration, we take our source and we try and return it to its original state," Young explains. "We try and remove the ravages of time, and wear and tear, and bad transfers and projection, or whatever " deterioration that's come into the element over time " eliminate that and leave behind something that is as close to the element's original state as possible."

Restoration work at Chace is accomplished in Sonic Solutions" NoNoise, a software-based digital system. Young is quick to point out, however, that digital processes which can rescue an aging audio track can also ruin it. "One of my biggest kicks " one of my crusades, if you will " is to fight the overuse of digital restoration tools. Any audio process can destroy a track. And the more powerful digital tools can destroy them quicker and with more devastation if they're overused," Young says. "There's a great temptation, when you have this massive digital power at your fingertips, to take something beyond where it should [be]."

On The Rocky Horror Picture Show, the mono stems were first put through a sonic restoration in NoNoise. "We cleaned it up, took out subtle little problems here and there," Young explains. "For instance, when Riff-Raff has just killed Frank-N-Furter, and they go, "You killed them! I thought you liked them!" And he screams, "They never liked me!" Well, that scream, at its source, was distorted. He yelled it and it got distorted on the mic. In 1975, when they mixed it, they had limitations as to how they could deal with distortion. Well, now in the year 2000, we've got better ways of dealing with that kind of distortion. So that line is" not completely undistorted, but it's a little bit less distorted than it was before."

With the original mono stems in the best condition, attention turned to the music multi-tracks. "There was no real clean-up needed on the 2-inch 24-tracks. They just needed to be edited to match the picture," Young says. "Greg Faust was the gentleman who did the editorial in Pro Tools of the multi-track masters. It took a lot of hard work cutting that stuff." Young points specifically to introductions on some of the songs, "like the vamp that happens before Frank-N-Furter's coming down the elevator for "Sweet Transvestite." That was not recorded that way " they edited that. So we had to recreate those edits."

Once cleaned up and properly edited, the music and vocal performances needed to be mixed down to create a finished stem. Young remixed the music himself, trying to remain faithful to the original mono stems, but taking into account the capabilities of the multi-channel audio format. "The multi-track music source had a lot wider frequency response and dynamic range than ended up on the mono mix. And that's because the mono mix was limited by the technology of its playback. So I used the mono mix as a template. They'd have sax recorded on the basic tracks through a whole song, but it only came up on the bridge. So I was going to follow those kinds of leads " basically re-create the music in the same vein. But of course, I was mixing for a format that had a lot more fidelity to offer, so I wasn't going to limit that."

The multi-track tapes, Young adds, "were great recordings and I did very little equalization. I did no dynamic processing whatsoever. I didn't compress it, or limit it, or anything like that. I stepped very lightly on the music. All I did was give it a stereo image, a little bit of ambience, and level adjust in the mix." Working on Rocky Horror, Young points out, "was a treat, because usually we don't get to remix." Most films, he notes, come in with music tracks already mixed for multi-channel, as was the case on recent Chace projects like Planet of the Apes and North by Northwest.

Because Young was essentially re-creating the musical portions of the film from original sources, some creative editing became necessary to maintain authenticity. "What I discovered as I started to scrutinize the multi-track tape was that there were vocal performances in the final mix that didn't exist on the multi-track," Young explains. "Additionally, there were some vocal performances that matched" but because the final mix had the vocals blended with other dialog sounds that I couldn't lose, essentially what I did was I built a dialog stem." This finished stem of vocal performances was pulled from both the 24-track studio tapes and the original mono dialog stem. Young cites the song "Dammit, Janet" as an example: "All the vocal performances matched perfectly. Except when Brad is on his knees showing her the ring, even though I had his vocal performance, I had nowhere where her "ooh"s and "ahh"s and reactions to the ring were the same. So for that one measure, I took the vocals from the mono master."

One surprise that turned up in mixing involved all the vocal parts for the film"s titular character. "Anytime that Rocky sings, he had versions on the multi-track, but none of Rocky's performances on the multi-track matched the movie," Young noted. The film"s music producer, Richard Hartley, had decided to change Rocky"s voice after the film had been shot, and the vocals were re-recorded. "And those recordings are probably sitting unmarked in a box in London somewhere," Young laughs. "But I did not have access to them." For the new 5.1 mix, Young had to pull all of Rocky"s vocals from the mono dialog stem.

There were other challenges Young encountered maintaining consistency between the original mono mix and the 5.1 version. "In one song, there was a guitar track that had been punched-in on " recorded over " for the very end," Young explains. "So in the mono master, the guitar performance matches the multi-track all the way through, and then at the very end of the song there's this subtle little three-note phrase of guitar that was missing from the multi-track. At that point I made a choice that I didn't want to throw away the whole song " the whole high fidelity multi-track version of the song " for a couple of pretty subtle little guitar licks at the very end... So in that particular song on the 5.1, it ends with other instruments, but there's two or three little guitar notes that are missing."

"There was one song on the multi-track that was not usable," Young added. "[During] "Don't Dream It, Be It," from the point where [Frank-N-Furter] jumps in the pool until "Wild And Untamed Thing," that chunk of music came from the mono. There were problems with the multi-track right there. Again, some tracks had been mysteriously punched in on, and there were instruments that were missing."

The final challenge that Young faced in remastering the music for the 5.1 version of The Rocky Horror Picture Show involved the film"s signature tune. A shortened version of "The Time Warp" featuring a saxophone overdub was used over the closing credits of the film " but was nowhere to be found on the multi-track music tapes. "Even if I could emulate the same edit that they did " shorten it " I didn't have the sax solo anywhere on any of my sources. The only way that we could maintain the same version of "Time Warp" at the very end would be to put the mono through the stereo conversion process," Young explained. "But not only would it change the stereo imaging, but there [would be] a noticeable and significant difference in the fidelity" So the alternative that I came up with is what you hear" I said, "I can't recreate that precisely, but I can do an instrumental, edited-down version of 'Time Warp.' It's a poor substitute as far as content, but as far as fidelity, at least we'd be ending on a high fidelity, consistent imaging, really kick-ass, punchy version of it."

After the 5.1 music stem was finished, it was time to add the dialog and sound effects, which existed only in mono on the DME. Chace Productions" solution for converting mono to 5.1 is the Chace Digital Stereo process. With this system, "stereo programmers" design cues which add directionality and ambience to mono sources. "Eric Johnson is the stereo programmer who programmed the Chace Digital Stereo for the track," Young says, adding that Chace"s Chief Stereo Product Specialist, John Blum contributed as well. "There's not a whole lot of directional movement in this film," he notes, but there are a few distinct examples. "Like when Eddie comes out on his motorcycle, you hear the motorcycle pan. And during the thunderstorm outside the castle, you hear there's placement of the thunder in surrounds... All the effects that are stereo, or that have stereo ambience to them, were created with the Chace Digital Stereo process."