In 2016 Asius and 64 Audio ended the licensing agreement they had. Where Asius was once producing the patented ADEL™ modules that were hearing protection components in 64 Audio In-Ear Monitors (IEMs), 64 Audio is now trying to produce its own modules. As a result, there has been much confusion in the marketplace as to what happened and if things will still be the same for 64 Audio customers. Here is a very comprehensive explanation:
Asius Technologies discovered the detrimental effects of pneumatic pressure – both on hearing preservation and on sound quality – and then invented, patented and commercialized the cure. We licensed the Ambrose Diaphonic Ear Lens (ADEL™) exclusively to 64 Audio. As a result, they were able to double their work force and offer a superior product that allowed them to become an industry leader in a field Asius Founder Stephen Ambrose established decades ago. 64 Audio then violated business agreements with Asius and came out with a knock-off that will mislead buyers who mistakenly assume a 64 Audio Apex affords the proven hearing safety and fidelity of the ADEL™.
64 Audio Apex Construction and Shortcomings
Since we at Asius enabled the development of Apex we owe our community an analysis of Apex. Firstly, Apex is not a next generation ADEL™. Only ADEL™ is used internationally by top celebrities such as Beyoncé in the U.S. and Peter Maffay (most #1 albums in Germany). Only ADEL™ is patented, licensed, adjustable, rooted in NIH and NSF research, independently tested by Vanderbilt University Medical Center, and provides a miraculous medical hearing restoration capability sought after by the world’s most celebrated artists such as Brian Johnson of AC/DC and Paul Stanley of KISS to name a few.
The 64 Audio Apex consists of (Figure 1) a housing with vent, 2 O-rings, activated carbon sponge filter; wire screen and a plastic retainer ring. This attempt to duplicate ADEL™ may avoid infringing on ADEL™ patents by replacing the second ear drum (a pneumatically compliant membrane) with a vented piece of activated charcoal sponge material but it is nothing novel as seen here - carbonair.eu
This boundary layer absorption phenomenon is also present in the ADEL™ ePTFE membrane (Figure 2), because of the membranes extensive microscopically fibrous topology. The 64 Audio Apex carbon sponge filter approach (Figure 3) (which Stephen Ambrose considered long ago) is so rigid however, that it merely acts like a resistive filter and doesn't have the compliance capacity or rapid response needed to mitigate the pneumatic pressures quickly or completely. In contrast, the ADEL™ membrane is only 1 micron thick, extremely low mass, moves faster than either the speaker or your ear drum and blouses like a wind sock to absorb extremely tiny pneumatic pressures. This can be easily observed using conventional testing procedures, especially in the bass frequencies.
While the carbon surface boundary layer on the 64 Audio Apex constitutes a somewhat pneumatically compliant membrane and therefore infringes on Asius’ patents, it is still not efficient enough to work for in-ear applications - which is why you will still suffer the audio fatigue, occlusion effect, lack of fidelity, phase problems, etc. It is not surprising that Apex technology has not been validated at Vanderbilt Medical Center or by any other credible party to show lower hearing preserving listening levels or to restore hearing function.
The screens and filters used by 64 Audio are merely arrangements of holes (vents). To the degree they are open as a collective they combine to form a large vent; to the degree they are closed, they constitute small ones. The mesh of the screen or sponge like topography of the filter simply adds more boundary surfaces around the holes which partially absorb or retard more volumetric flow. In any case, they are predominantly acoustic resistors, while ADEL™ membranes are capacitors.
64 Audio Apex Operational Disadvantages
For example, consider a house with frozen plumbing in the walls; once thawed, the cracked pipes begin to leak. Patching the leak puts a resistor over the escaping pressure and only transfers the leak it to another weak or fractured area, thereby causing further pressure damage. But a bucket placed under the leak constitutes a capacitor which effectively captures the pressure without conveying it elsewhere to harm other fragile areas.
The ADEL™ Membrane technology is like a pneumatic "bucket" or capacitor which only has to be big enough to hold the relatively small speaker displacements of the ear canal. And it does this so well, we intentionally tension it in order to keep it from absorbing too much pressure.
All holes or vents found in 64 Audio’s Apex allow sound to leak both in and out of the ear, and therefore require more SPL and compromise a complete seal of the ear canal. ADEL™ Membranes focus much more of the sound and comprise a complete seal of the ear canal which only acts like it's open.
Resistors such as screens or filters found in 64 Audio’s Apex release both pneumatic AND acoustic pressures, thereby requiring higher listening levels across full spectrum sound. Unlike ADEL™, these devices are known to prematurely trigger the acoustic reflex and cause audio fatigue.
Unlike an Apex vent/filter which is always open, ADEL™ membranes are selectively open at higher pressures and completely sealed at lower pressures. This allows for overall equalization of higher in-ear device insertion pressures while affording a complete seal for acoustic pressures which are variably stripped of their pneumatic components with minimal leaking of acoustic components.
Being pneumatically compliant, ADEL™ membranes mitigate pneumatic pressures while maintaining the acoustic seal and can allow for adjustable impedance matching of both in-ear as well as external sound pressure levels. External sounds must match the impedance of the un-tensioned membrane to pass through freely. Additionally, the extremely lacking Apex pneumatic compliance is not adjustable and cannot be focused or made to individually match each ear's impedance.