Diffusion at source

A3D Technology - Diffusion At Source - not only mitigates against specular reflections (proven to corrupt the acoustic envelope we listen to) but also, perhaps more importantly, A3D enables loudspeakers to output their energy in a purely radial flow. In short, the acoustic energy of A3D speakers travels outward in a radial pattern, whereas conventional loudpeakers create a number of 'zones of confusion’ in which the energy flow (acoustic intensity) is not radial (i.e. toward the listener) but is tangential (think of it as a bit like the wake of a boat) - effectively robbing sounds' pure spherical wavefront of the energy we listen for.

This ‘energy conservation’ is very important. When all the acoustic energy is travelling radially from its source, there can be no energy travelling in a direction that might corrupt that sound-wave. This is not the case for conventional speakers, which will corrupt the sound-wave with their off-axis tangential energy (the main reason the ‘sweet spot’ of conventional speakers is so narrow).

The above is particularly pertinent to stereo/ambisonic signals, where timing cues are critical to our audiology’s ability to reconstruct the sound-stage of the original recording. Conventional speakers’ non-radial acoustic energy distribution corrupts the timing (and intensity) of such cues, leading our highly sensitive audiology to create a ‘false reality' of the playback sound (something which we readily recognise as ‘not real’). Tangential energy locations might even appear as 'phantom loudspeakers’, producing cues that have nothing to do with the audio signal! We're of the opinion that this is why recordings mostly 'sound like recordings’.

A3D’s energy conservation, and much bigger sweet spot, means A3D'd speakers deliver even more accurate cues when configured as a stereo pair. Add to that their autodecorrelation, which not only prevents specular reflections but reduces the 'precedence effect' (a psycho-acoustic effect that collapses the sound stage when one sits nearer to one speaker than the other in a stereo pair) and you may understand why A3D is so important to spatial sound - and particularly to multi-speaker surround sound.

A3D’s mathematical modelling shows exactly how A3D speakers work - and exactly why conventional speakers can’t match them. But don’t just take our word for it - do the maths yourself. We’ll share ours with you if it helps - drop us an email.

Following our latest Mathematical analysis, we are confident that A3D is the most significant contribution to the playback of recorded sound since the invention of the Dynamic Loudspeaker. In fact, all the data - and listening tests - suggests that A3D speakers behave pretty much exactly as an 'idealised point-source'. Whilst this has always been considered the 'gold standard' it has also been thought impossible - until now!

A3D's 'acoustic apodisation' through 'Diffusion At Source' enhances the listener’s perception of Intimacy, Envelopment and Clarity.

Listening through A3D technology really does sound 'like being there when the recording was made'.

Basis of the Technology – Several methods

The benefits of A3D technology can be achieved through several different methods:

Reflector – the original. Using a modified Quadratic Residue filter, the sound is bounced off it to create ‘Diffusion At Source’. This produces a clearly audible (and measurable) effect in the frequency band that contributes to our spatial awareness. This approach is readily compatible with conventional speaker-driver design, construction and components.

Array – the second method realised. Using multiple drivers and digital delay techniques to create ‘Diffusion At Source’. This method is particularly suited to high-power applications such as concert PA.

Manifold – 'the third way'. Using a multi-port design to create ‘Diffusion At Source’ from a single driver, this low-cost method is particularly suited to applications in consumer audio, TV, Smartphone, in-car audio and, information PA and ceiling speakers.

The Patents

A fuller explanation of A3D’s technology can be found in their patents - which are best found through Google search, as they are constantly being added to.

However, to explain how A3D got there, you simply need to know that they ‘reversed the arrow’.

The following are amateur videos - the first is Dr Toby Gifford's presentation at the recent AES conference in Burlingame - apologies for the sound but it was shot on his phone. In it he discusses our science.


The next video considers the impact of reflection in acoustic envelope accuracy


The final video considers the impact of Acoustic Apodisation on acoustic envelop accuracy and its impact on the perception of 'reality' in sound


A3D History

Twenty-five years ago, exploiting his knowledge of Physics, Mathematics and Psychoacoustics, Joe Hayes made a breakthrough in audio playback, discovering how to generate what he at the time described as an 'acoustic hologram' - stereo sound whose strong image was unsullied by the listening environment.

Since then the company he founded, now known as Acoustic3D Holdings Ltd, has conducted research and development to the point where Joe and his team have productized the principles behind his discovery - diffusion at source - into the A3D patented IP, available exclusively through Vastigo Ltd.