Vienna Symphonic Library Announces New Sampling Reverb System

Jul 11, 2003

The Vienna Symphonic Library has announced an upcoming addition to its comprehensive virtual orchestra solution -- "space". Vienna's new MIR (Multi-Impulse Response) technique, commonly known as "sampling reverb," is a method of putting any signal inside an actual acoustic space, be it a concert hall, film scoring stage, or even a small room.

This new component is another major step toward completing the master plan for the Vienna Symphonic Library, providing composers and musicians total, independent control over both the instruments and the acoustic environment in which they perform. For example, the user could place a small chamber ensemble inside the intimate parlor of an old European palace, or bring the entire Wagnerian orchestra into an actual Grand Concert Hall. Furthermore, a simple graphic user interface will allow the user to actually click and drag the instruments of the orchestra onto the virtual stage. Each instrument's response characteristic will be individually and automatically calculated within the context of the overall space, creating an accurate, unified ensemble sound with pristine imaging in any acoustic environment. In addition to stereo, all surround sound formats including 5.1 and 7.1 will be supported.

"This approach is completely different, much more realistic and flexible than that of other orchestral sample libraries that are recorded inside a concert hall," says Vienna founder Herb Tucmandl. "The creative restrictions of those reverb methods are massive. Spatial characteristics are frozen and unchangeable, the user has no flexibility to alter the size or acoustic properties of the room, or to change the space altogether. Plus, each time more than one note is played, the sound of that reverb is duplicated over and over again. Play three notes and the unfortunate result is the cumulative, layered sound of three halls. Vienna Symphonic Library's samples were intentionally recorded in a smaller controlled environment, so that we could allow our users the ability to choose whatever concert hall or recording environment they wish with technical, real-world accuracy using our MIR reverb technique."

The basic idea is simple. Just as it is possible to digitize, i.e., "sample" an instrument with all of its wealth of expression, one can also digitize the characteristics of an enclosure, be it a small room or a concert hall. To do this, the response of a real space to a precisely defined acoustic impulse is recorded, and then "imprinted" onto an acoustic signal in a mathematical process called convolution. Theoretically, the result is the same as if that signal had actually been recorded in this space.

Until now, the immense computational requirements of convolution barely allowed more than two or perhaps four channels of sampling reverb, which was derived mostly from unidirectional mono impulses. The Vienna Symphonic Library takes this technology to the next level, capturing the great concert stages of the world in their full glory, wall to wall, floor to ceiling, in all three dimensions. MIR is the key to success. This engine places each instrument of the orchestra into one unified acoustic space, the space that the composer chooses.

The Vienna Symphonic Library's founding principle is as simple as it is compelling in its fundamental logic: the "stage" of a concert hall can be subdivided into a number of sectors and from each sector a special impulse can be released in up to seven directions.

The Vienna Symphonic Library has taken this concept a step further, with the reverb engine actually serving as a complete mixing station. With a few intuitive movements the user can control every parameter of a virtual orchestration, including volume, position on the stage and distance from the virtual microphone. All of the necessary spatial parameters are connected in one macro environment. There will also be expert settings in the background, enabling more refined control of the environment and instrument placement.

The results will be heard in real-time in preview mode. The high-definition final results will initially be calculated offline. However, it's merely a matter of time before conventional computer systems are fast enough to enable high-definition real-time convolution. Output on up to eight audio channels covers even extravagant surround formats, allowing the complete, accurate recreation of the entire acoustic space in 5.1, 7.1, and other three dimensional systems.