A and B-Format Hires Decoder

On founding Illusonic, B-Format decoding has been a priority. We have developed hi-resolution B-Format decoding since 2006. Though the market was not ready, but off-spring derivative beamforming techniues made it to commercial pro-audio products from Schoeps (SuperCMIT) and Sennheiser (Esfera).

We are pleased to see that thanks to demand vor virtual reality audio, B-Fomat (= ambisonics) decoding has gained traction again. Now re-investing in this technology, we have refined it further. It is ready for any product that needs great AR/VR audio.


B-Format Upscaling

Examples of VR microphones are the venerable Soundfield microphone, Tetramic, and recent Sennheiser Ambeo microphones.

These microphones are based on four directional microphones located on a tetrahedron. They offer first-order ambisonic (B-Format) signals, suitable for VR audio.

The most known higher-order VR microphone is the Eigenmike. While offering higher order HOA signals, it suffers from basic audio quality. While a Soundfield microphone is based on directional microphone elements quite expensive, a higher order microphone is based on cheaper omni-directional microphones.

Unfortunately, there is the trade-off between “pro audio channel quality” and higher order directionality.

Illusonic B-Format Upscaling offers the best of both worlds: pro audio channel quality and high order directionality. It is implemented by using high quality first order microphone and signal processing for extension to higher order.


A-Format Coincidence Correction

The venerable Soundfield microphone and Ambisonics have been an impressively visionary. But an annoying limitation of even modern Soundfield-type microphones arises from the fact that the microphone elements are not precisey located at the same point.

The resulting limitation is that directivity pattern above 2-4 kHz are highly deviating from the desired directivity pattern, impairing overall sound quality.

Illusonic’s A-Format Coincidence Correction time-frequency adaptively aligns the phases of the four microphone elements, such that conversion to B-Format can be applied without interferences and without a need for spectral correction filters.


Spatial B-Format Equalizer

With our new B-Format equalizer you can modify A or B-Format signals in post-production. Very useful for controlling timbre of different objects in recordings. Also the balance between different objects can be controlled. Gains and different equalizers can be defined in different directions. A focus parameter determines the spatial extent of the corresponding signal modification.


Consumer B-Format Capture

Do you need VR audio capture in a VR camera product?

Realistic form factor and physical consideration will dictate that you can’t use directional microphone like a Soundfield microphone.

Thus you need to obtain as good as possible B-Format/HOA signals based on 4 or more omni-directional microphones. Illusonic signal-processing will provide the optimal conversion with broadband aliasing-free directivity pattern.


VR Soundbar (XTC)

If you want to render VR-audio (binaural) over loudspeakers, Illusonic crosstalk-cancellation filters will do the job surprisingly well:

a single person in the sweet spot gets a full 3D VR sound experience

while listener everywhere else get a correct coloration-free sound


A/B-Format Binauralizer

Converts A and B-Format signals to binaural. Advanced spatial analysis followed by mapping the signal to head related transfer functions yields high spatial resolution and high quality result. 3DOF Headtracking is supported.



Our A and B-Format Decoder and Binauralizer support “A.1-Format”. A 5th omni-microphone channel is added to A-Format enabling decoded signals with great bass.