The 'Amber' HRTF

"Amber" is a 3D HOA "binaural" decoder method for headphones that is available in Rapture3D and our pro audio products. This uses the free IRCAM AKG "Listen" HRTF data set.

This works best on headphones. If you're using Rapture3D playback or gaming you'll need to put your computer into "Headphone" mode through Control Panel, or select "Headphone Stereo" or "Headphone Stereo (Compat.)" in the Rapture3D Speaker Layout program. Then on the "Decoder" tab, select "HRTF (Amber)" if it isn't selected already.

This way of listening to sound relies on HRTF processing - depending on the direction from which sounds are coming, we filter the sound differently to take into account how sound would curve around your head and ears in the real world. As heads are quite varied, HRTFs are a bit of a "black art", and different HRTFs work better for different people.

The IRCAM AKG "Listen" HRTF data contains measured HRTFs from about 50 different people - this must have taken a lot of effort and we're very grateful to the good folk of IRCAM for doing the work and making the results available to the world! What we've done is analyse this data and come up with an 'average' HRTF that is a sensible compromise, using some new work. As it's an average, it wouldn't be perfect for any of the people actually measured, but hopefully not awful for any of them either! It's certainly much better than conventional "panning" techniques.

The Amber binaural decoder is also used in our professional O3A Decoding, O3A View and Binaural Surround plugin libraries.

Rapture3D also includes a number of other binaural decoders and, as of v2.7.0, the Advanced edition of Rapture3D includes experimental support for import of personalised HRTFs from AES69 files.