ConvolverVST. VST (Virtual Studio Technology) is a popular format from Steinberg for loading plug-in effects into audio sequencers, hard disk recorders, sound editors, and trackers ConvolverVST is a convolution plug-in for (version 2.4 of) that format. Applications A potentially interesting application of convolverVST would be with the Audiotrak Prodigy 7.1 sound cards, which can filter the input signal in real time without a sequencer. (I have not tried this.) This will allow convolution processing to be applied to sound from any application running on your system. A similar approach — application of a filter to the sounds generated by any program installed on your computer — is available through the SonicStage Mastering Studio Audio Filter feature available with some Sony Vaio machines.
Limitations The convolverVST plug-in is under active development. The VST standard has evolved over time and is not precisely specified. Getting started To install convolverVST: 3. 4. 5. A configuration (text) file 6. Conversion between B-format and UHJ. This page explains how to use the Aurora plugins for converting between B-format and UHJ surround formats. NEW - Also usage of Audiomulch and SIR (Super Impulse reverb) are explained! A B-format signal is, in general, a 4-channel signal (WXYZ). W is the sound pressure signal, as captured by a perfectly omnidirectional microphone. X, Y and Z are the "first order spherical harmonics" of the pressure field, which are obtained by weighting the pressure impinging on the microphone with the cosines of the angles between the direction-of-arrival and the corresponding cartesian axis.
The Cartesian reference is conforming to ISO standards (for example, ISO2631), as in the following picture: It is possible to "pack" the horizontal B-format signals (WXY) in just two channels, suitable for stereo reproduction, and called UHJ. Here the problem of converting a three-channels B-format signal (WXY) to a two-channels UHJ (LR) is solved. L = 0.5 * (0.9397*W + 0.1856*X - j*0.342*W + j*0.5099*X + 0.655*Y)
3D Audio Links and Information. Introduction This page concerns itself with techniques for reproducing three-dimensional sound images. The focus is on use of multiple speakers to reproduce complete `fields' of sound in which the listener can sit or move around. This is rather different to HRTF-based techniques which are either reliant on headphones or a motionless listener facing in the correct direction at the `sweet spot' of a listening area. Tools are introduced which also construct more conventional mono or stereo recordings. Ambisonics Ambisonics is a technique developed initially by Michael Gerzon in the early 70s. It provides a way to encode (sometimes by recording) three dimensional soundfields.
Ambisonics, unlike some other `surround' techniques, is based on solid mathematics. I've set up a company specialising in Ambisonics and related technologies, Blue Ripple Sound . "Ambisonics" is a registered trademark of Nimbus Communications International. Second and Third Order Ambisonics - the Furse-Malham Set Links: WigWare » The Blog of Bruce. During my research, it soon became clear that although a number of people were carrying out research around the area of Ambisonic surround sound, few people were enabling others to actually use the technique! To hopefully help remedy this situation, I’ve created a number of VST Plugins that can be used in many Digital Audio Workstations (DAWs). I may put instructions on how to use them up here at some point, but in the meantime, tutorials can be found on the Ambisonics Music Creation grou.ps website that I’ve created to help support some of my teaching here at the University of Derby.
The plug-ins are available for Mac and PC, and can be downloaded below. The plugins are free to use for personal and educational use. If you’re using them for commercial work, please contact me, as it’s nice to know when and how my software is being used (a credit would also be nice, and donations are always welcome!) 1st Order WigWare Mac (These have now been updated to work on Mac OSX 10.4 and 10.5) Aristotel Digenis | Audio, code, and games. Ambisonic.Net - where surround-sound comes to life.