Widescreen Review, January/February 2001, Volume 10, Number 1, Issue 45, by Perry Sun

Brant Biles and Bob Margouleff, the well-respected surround sound duo and principals of Mi Casa Studio, have worked with New Line Cinema on several, if not most of their recent DVD releases. They have provided their expertise in the preparation of soundtrack masters for the consumer home theatre. But perhaps the most ambitious project to date that was assigned to Mi Casa by New Line Cinema was to re-mix the soundtrack for Se7en, with the participation of director David Fincher and the film's original sound designer, Ren Klyce. Furthermore, Margouleff and Biles were asked to create a new Dolby Digital Surround EX-encoded 5.1-channel mix (refer to Issue 32 for more information).

The soundtrack Se7en was originally a 5.1-channel production, so the starting point for the re-mixing was the 5.1 final mix stems for ambience, effects, dialogue and music. These existed as 35mm magnetic archives and were transferred to digital Tascam DA-88 tapes at 24-bit/48kHz prior to delivery to Mi Casa. The first step with these stems after arriving at Ml Casa was to listen to them carefully, and "clean up" any noises, clicks, pops, etc., that should not be present. Film sound, when monitored in a nearfield environment can be more revealing of sonic details than on the dubbing stage (where the final mix, was originally, created).

Fincher and Klyce then joined the Mi Casa team as they listened to the final mix in its original form. Biles recalled that the question he and Margouleff then faced was, "Where [in the soundtrack] are you going to derive the third surround channel?" The response was, "We don't know! We have to go through the film and the soundtrack." And this was basically the approach taken with creating the new back surround channel. The ambience and effects stems were sonically scrutinized, scene by scene, for possible cues, pans, etc. that could be redirected to back surround. For example, there were scenes with helicopters flying behind the listener, for which a left-right sweep was re-panned to go through back surround as well as the left-right surrounds.

In other scenes, a stereo reverberation in the surrounds would actually be redistributed to the back surrounds as "mono." As Biles explained, "One particular scene is in the library, where Morgan Freemen is photocopying some pages for Brad Pitt. There's a close-up shot of Freeman, where the ambience is in stereo for the surrounds, which then cuts to a long shot, and then the surround ambience folds down to mono." Therefore, the back surround was engaged to help impart the sense of a different point of view. 

In yet another example of back surround usage, Morgan Freeman throws his metronome across the room shattering it into pieces with some of them being rendered directly behind the listener. It should be noted that only the ambience and effects stems were re-worked for the Surround EX mix, while the music and dialogue stems were not affected (but were processed for other reasons such as reequalization and corrections for distortion with voices).

The re-purposing of the Se7en soundtrack was not limited to incorporation of the back surround. Additional low frequency information was added to the LFE. The bottom-end of music and percussion was filtered from the main channels, equalized to a certain extent and then incorporated into the LFE. Margouleff felt that what was known as the LFE (low frequency effects) channel should contain not only effects but also the low-end of other sound elements, most notably music, for which the deep bass components play an important role in the soundtrack experience.

After Margouleff and BiIes took their first pass at reworking the soundtrack they presented the results to Klyce and Fincher who then took notes and made some suggestions which were subsequently addressed. Many of these were actually corrections to imperfections associated with the original mix such as an imbalance of dialogue level (resulting in intelligibility problems), which for one reason or another weren't corrected for the theatrical release. In another situation, the filmmakers actually asked for some of the inherent noise to be restored in a particular scene after it was initially removed as part of the "clean up" process described earlier. Other corrections included the incorporation of last-minute additions to the original printmaster but were never added to the mix stems and now had to be included as part of the new DVD mix.

The Mi Casa team also offered their suggestions for some modifications to the filmmakers. For example Biles described a scene where a door closes off-screen to the left but the associated sound originally turned up in the center channel. Klyce agreed that the effect should be relocated to the left channel. In another "corrected" scene Gwyneth Paltrow steps into the room from the right but the footstep sounds were initially reproduced from the left. 

As part of the soundtrack remastering, Mi Casa reequalized each of the stems for home theatre playback as they have done for other DVD titles from New Line Cinema, except that they usually work with the final mix rather than the upstream elements. Therefore such DVDs won't require the use of re-equalization from your receiver or surround processor. A list of Mi Casa's DVD soundtrack projects can be found at www.micasastudio.com if you want to make sure that you're not needlessly applying reequalization for the New Line Cinema title.

The new Surround EX-encoded 5.1-channel master was created from the combination of the modified mix stems, now in discrete 6.1 channels, which were converted from digital to analog. This 6.1 mix was then input into the proprietary Dolby Digital Surround EX encoder and the 5.1-channel output was then redigitized at 24-bit/48kHz and then stored on Tascarn DA-88s before being sent off for encoding to Dolby Digital. It should be interesting to note that besides the film itself the audio for the menus were created with Surround EX (and then encoded in Dolby Digital).

Subsequently, after Mi Casa had completed their work on the Surround EX 5.1 mix, they were asked by New Line Cinema if they would consider creating a fully-discrete 6.1 mix of Se7en, for DTS-ES Discrete 6.1 (see Issue 41 for background information). Margouleff was initially skeptical, believing that a 6.1 mix and a Surround EX 5.1 mix would not be all that different. But after creating the 6.1, the perceived differences, as he described it, "were an eye-opener. The distinctions between the two versions were quite a revelation!" Biles pointed out that a limitation with Surround EX was that there was tendency for left and right surround information to collapse to back surround, and that discrete 6.1 allowed for left and right surrounds to remain separate, such as for the music, which for the most part Mi Casa never intended to purposefully allocate to back surround.

For the creation of the 6.1 mix, the source was mostly the new 6.1 effects and ambience stems previously created for the Surround EX 5.1 mix, and in a few cases, the original 5.1 versions of these stems, passed through a Surround EX decoder to obtain three surround channels. As a starting point Biles and Margouleff listened to the 6.1 sterns. What they discovered was these stems were actually "missing" some of the back surround information that was heard with the decoded Surround EX 5.1 mix. Surround EX encoding and decoding, by its very nature, introduces some information into the back surround, due to the imperfect channel separation. So what was happening was that occasional, unintended collapse of left-right surround information into the back surround for Surround EX wasn't heard with the 6.1 stems.

Margouleff and Biles determined that such information needed to somehow be "Restored" to the 6.1 mix, and proceeded to do so by two means. The first was to use the 6.1 stems and draw some extra content from the left-right surrounds into the back surround channel. In a few cases, the original 5.1 ambience and effects stems were input into the Surround EX decoder, and information from the matrix-derived back surround was added to the 6.1 stems.

In the creation of the 6.1 mix for DTS-ES Discrete 6.1, no work was performed on the screen channels so therefore they are identical to the Surround EX 5.1 version. Upon asking the question of whether the discrete version is really better than the Surround EX-encoded mix, Biles remarked that he "toggled back and forth between the Surround EX-decoded mix and the discrete version, making sure that the discrete was indeed better. I believe that there's a pretty drastic difference [between the two version], in terms of spatiality in the surround channels." Be sure to take a look at Shane Buettner's in-depth review of this creatively repurposed, standout soundtrack, also featured in this Issue 45.

Perry Sun is the Movie Sound Editor for Widescreen Review.

He can be contacted at perry@widescreenreview.com.