Understanding Surround Sound Production - page 3

The Genelec Demo System

The above slides represent the monster system Genelec set-up for the demo. Pay particular attention to the included pictograms to the right on each of these slides. On them you will note the recommended room sizes, distance to listening position, low frequency cut-off, maximum SPL, etc. Note also the transducer complement of each system along with the amplifier to which the transducers are coupled. Finally, the tone control section shows the Genelec's system tuning flexibility once they are installed. Usually, these controls are set during initial calibration and not touched thereafter.

The Soundfield Microphone Array
Soundfield's approach to capturing both stereo and surround sound is truly ingenious. The goal in designing the Soundfield microphone array was to accurately and realistically capture a three-dimensional audio experience.

Based on a patented multi-capsule array each of the four capsules in the array pick up sound from a different direction. It is this information which is used to capture a soundfield. The four signals from the capsules are collectively named A-Format. Once the signals are captured they go through one of three available Soundfield control unit models which convert the signals into a proprietary Soundfield B-Format.

After the SoundfieldB-Format is recorded onto four tracks, this information can be decoded into any required audio format: mono, stereo, M/S, 5.1,6.1,7.1 or any custom multi-speaker playback system.

In addition to the three stand-alone control units Soundfield has also introduced the Surround Zone which is a software plug-in available for Nuendo (Steinberg), Cu base, SADIE 5 and shortly, ProTools.

And Finally…DTS!
Rodney Orpheus, DTS' European Entertainment Manager, gave some very interesting statistics and introduced DTS' patented technologies which will take them into the future.

• Worldwide, more than 280 million consumer electronics products containing DTS technology and trademarks have been licensed: these include-
• DVD players, A/V receivers, amp/pre-amps, HTIB
• Playstation®2 game consoles (70+ million units)
• In-car audio processors and head units
• PC-based software decoders and PC soundcards

And the technology? Well, the Eagles classic "Hell Freezes Over" stands as the first, great DVD concert recording I've ever owned. It came in the original DTS Digital Surround format way back in 1994. I've been a fan of DTS' natural sounding algorithms ever since. It's hard to know what else to say about a technology which is so transparent that I can't detect that any processing or compression is taking place.

Let me put it this way. By the time I'm voicing a speaker system which I've designed from the ground up, I've got a pretty good idea of the ultimate capabilities of the drivers, in the given box, with the chosen crossover configuration. The (usually) ported design and cabinet bracing are taken care of as listening begins. After this step, the sound begins to converge closer and closer, toward its ultimate capabilities, Then I'm making tiny changes to the crossover components, all the while rechecking (by measurement) that I'm maintaining the frequency balance and (flat) response that is my target.

At the end, I experience the sound "locking". The woofer, tweeter, enclosure and crossover all converge to give a sound that is at once natural, smooth, easy to listen to but accurate and non-hyped. This is the sound I hear with a great recording in the DTS Digital Surround format. I hear the music, not the format. That's what I call a great technology.

Rodney's demonstration of DTS' 96/24 with 5.1 channels of high resolution audio and full motion video were followed by and a clip from Lord of the Rings in ES 6.1.

And lastly, the teaser. DTS HD has been chosen as a mandatory format when high definition DVDs are introduced sometime next year. Audioholics will be there to review DTS HD's sound quality as soon as the first products become available. Perhaps at the 2005 CES…