Back in December 2003 Audio Ease went to several rooms to make samples using a larger than usual set of source positions. The goal was to find out what exactly the influence of stage position is on the impulse response, so an algorithm could be derived that allows the source sound to be moved around on the stage of any hall or room available in Altiverb. The following is a demo using Altiverb's resulting 'stage positions' feature for a specific case:
Creation of a convincing stereo image of a sampled orchestra on a stage
The percussion section is placed in three different positions on stage in the same hall (Konzerthaus, grosse saal). The image is an interface screen shots of the current setting being used. There are two speakers on stage because the input audio is a stereo mixdown of a percussion section.
We asked Maarten Spruijt, composer, maker of primary demos for such renowned sample manufacturers as Vienna Symphonic Library, Spectrasonics and ProjectSAM, to compose a short movement for us. As his instrument he chose to use the Vienna Symphony Library of orchestral samples.
This is what his dry, un-positioned orchestra sounded like:
We asked Maarten to distribute his separate instrument tracks over the stage using Altiverb's stage position feature. Each track was to be played back from a different position on stage.
First thing to do was insert Altiverb on each of the 15 instrument tracks. Each Altiverb loaded with the same microphone setup. A setup close to a stage was used to achieve a wide stereo image:
To ease the load on the CPU, and to remain more flexible, the choice was made to not render the full tail in all instrument tracks. Instead all 15 Altiverb instances in the instrument tracks only use the direct sound and the early refs (reflections).
On the master track, one Altiverb will take take care of the tail. This way the longest part over the reverb is applied once instead of 15 times and by using this setup you can easily change the tail sound.
Then the Altiverbs were switched to their Stage positions tabs. The direct gain control now becomes disabled, as the Stage positions control takes over the gain of the direct sound.
Stage positions were selected, by dragging the speaker for mono instrument tracks, or by dragging both speakers for placement of stereo mixdowns of instrument groups.
Classic orchestral positions were selected, with percussion in the far back of the stage.
Maarten's positionings are available as Altiverb presets in the preset menu under "/Orchestral/Orchestral Positioning track inserts/")
With all of the instruments placed properly a final Altiverb was put in the master channel to take care of the reverb tail. Mechanics Hall in Worcester MA was selected to provide the reverb tail. The instrument tracks now provided the direct sound and early refs in the production, so the direct sound of the master Altiverb was set all the way down, as well as some of its early reflections (early).
With the master now only rendering the tail, the mix between the placement and the tail could be made using the wet/dry control of the master Altiverb.
Check out this final result. A very convincing orchestral stage, that could not have been achieved using traditional panning.
Alternatively, here's a wetter setup, that makes use of the Amsterdam Concertgebouw for the reverb tail.(Maartens alternatives are available in the preset menu under Orchestral Reverb Tails)
The audio demos on this page are optimized for playback on speakers, not headphones.
You can download all audio featured on this page also as non-compressed 44.1 kHz, 16 bits AIFF files.download all demo audio