CoiL
Member of the Trade: Wood Audio Accessories & Modifications
There`s more to it - it`s the way that membrane acts and "equalizes" pressure. 64audio had nice indroduction video about it showing membrane action. You`ll find it if You search.So this ADEL tech is just an aperiodic vent where by using a vented membrane, they alter the resistance of flow through the vent. It seems to me lots of IEM these days have venting holes with membranes already, and some people modify them using micropore tape and similar materials and needles to enlarge the hole, or is there more to it?
The "membranes" You talk about lot of IEMs having - most of them just use different kind and thickness (air flow passage) filter material. ADEL membranes act differently.