A home cinema sound system has beaten a professional cinema sound system hands down. In three demonstrations looking at digital projection, Jon Thompson from the BKSTS put DVD to the test. Although primarily looking at picture quality, one of the overwhelming comments made by each audience member was that the sound of DVD was far superior when compared head-to-head with a 35mm print.
At the Warner Preview Theatre in London, representatives from KEF, Denon, DTS, Barco, Snell & Wilcox and Warner Bros, as well as some film industry luminaries, such as two-time Oscar winning cameraman Freddie Francis, Oscar winner Ronnie Taylor and Oscar winner Billy Williams, were present to cast their eyes over picture quality. To assess the audio side were mixing engineers from Abbey Road Studios and various sound designers from the films shown.
The aim of the demonstration was to compare picture quality of DVDs with their 35mm counterparts. The films that were viewed side-by-side were Michael Collins, Out of Sight, 12 Monkeys, Singles, The Avengers and Austin Powers. Thompson began by projecting a show print, which is an original print made from the original camera negative and then looked at a released print, which is made from an inter-negative, which is three generations down from a show print. These were shown on a standard Westrex 35mm projector, with a 2kw Xenon lamp behind it.
To project the DVDs he used a Meridian 800 DVD player and a Snell Wilcox
interpellator, with a pair of stacked Barco projectors. The interpellator was used to upscale the DVD image from its native resolution of roughly 740 by 480, to 1200 by 1024. As well as doing this, the interpellator removes the 3:2 pulldown that is inherent in an NTSE transfer of a motion picture film. In doing so, the output of the interpellator is in progressive scan. The superiority of progressive scan over a traditionally interlaced film is startlingly obvious, as there is no line structure, which is an inherent bain of home cinema.
To begin, a show print was projected, this is the highest quality print available of a film. Unfortunately, most cinemas only show released prints; therefore most people do not see the true potential of the film. Roderick Snell, of Snell & Wilcox, commented that from a show print to a released print there appears to be a drop in resolution of about 50%, due to the copying stages that film goes through.
The DVD picture being compared to the original 35mm print was obviously not as sharp or with as much contrast this was to be expected due to the compression and the amount of loss in the MPEG 2 encoding system. However, most people commented that the picture was far better than they expected, and were surprised that the difference between 35mm and DVD on a screen 12ft across, was not that great: the films could be reasonably enjoyed. Roderick Snell commented that this could give a new lease of life to low budget films that otherwise could not be exhibited on 35mm due to cost. However, in a comparison between the Steven Sodenburg film Out of Sight, the DVD, taken from a high definition master, despite looking sharp and as vivid as the original 35mm print, lost many of the original subtleties, this also became apparent in the opening scene of The Avengers on DVD. Roger Pratt had used a lot of delicate filtering which was completely lost in the transfer.
From a technical standpoint, films that had been telecined using high-definition transfers or using the Philips Spirit Datacine (also high-definition) were much preferred and gave a much more filmic look to the DVD than films telecined on Rank Cintel telecine machines.
On the video side the equipment used was almost professional end. But on
the audio side, mid-range, mid-price domestic equipment was chosen. Thompson used Denon’s new THX AVC-A1D surround amplifier and KEF’s reference THX speaker system. These were competing with a professional JBL theatre system and professional Dolby Digital decoder, which were roughly three times the price of the home cinema equipment it was being compared to.
The Denon and KEF system consistently outclassed the professional system.
The overall audio resolution of the DVD was higher and the positioning of the sound appeared to be a lot more solid, due to the KEF speakers. KEF rear di-poles were used against a rear array of JBL speakers; this produced more dynamic front to back panning, whilst the bass was tighter and more robust. The Denon system was set up by Roger Batchelor from Denon, in one hour. He stated that if he had had longer, by tweaking some of the parameters he could have achieved an even greater overall sound. One can only imagine how that would have been, as the results produced at the time were staggering.
When comparing the two versions of The Avengers, the DVD sounded so different that it was like listening to another film. It was noted that the Dolby Digital track on the 35mm print was inferior as it was competing with dirt, dust and scratches. It was apparent that the Dolby Digital System on film, has to do a lot of error concealment, thus reducing the resolution of the overall sound. The DTS theatre system in comparison suffers from none of these problems, but it was remarkable as to how superior the Dolby Digital track on DVD was to the DTS Theatre System, with the DTS DVD System sounding better again. Chris Haliborne of DTS commented that it was not surprising, as the DTS DVD System used the latest technology in its
algorithms, and its coding system is far superior to its original theatre systems’ encoding; thus producing far higher resolution sound. Chris was pleased, but not surprised that DTS DVD had sounded so good, stating that, “It is simple mathematics, our track has a far higher data rate, thus preserving more of the integrity of the original sound.”