Bformat2Binaural - Ambisonic Binaural Decoder
Decode up to 1storder Ambisonics for playback over headphones. By: Charles Gregory - 2003-2004 MSc Music Technology student at the University of York.
In this plug-in, four speaker feeds are derived from an Ambisonic sound field, and those feeds are convolved with the corresponding HRTF for those speaker positions. The speaker positions are 0, 90, 180, and 270 degrees. Since the left and right ear HRTF are the same at 0 degrees, there is one less convolution required. Same applies for the rear 180 degree position, avoiding a total of two convolutions as opposed to eight required if the speakers were positioned at 45, 135, 225, and 315 degrees.
While this method requires less processing power, it does not 'seem' to provide as clear a sound field as when decoding speaker feeds with positions 45, 135, 225, and 315. More trials need to be done into this.
Even though it uses the compact 128 tap HRTF set available from the MIT Media Lab instead of the full 512 tap set, it uses straight convolution as opposed to FFT convolution, and as a result is quite CPU intensive.
Features: 1st order; Horizontal; 128 tap filters; 64 bit processing.
Download (PC Only)
Note: Thanks to Bill Gardner and Keith Martin from the MIT Media Lab for the HRTF data sets.