The A.R.T. principle
Besides the transformation advantage the construction of the membrane in single stripes avoids the typical break up of stiff domes or cones at higher frequencies and the resultant dynamic limiting. Another factor in dynamics is diaphragm area. What you see is what you get. The cone area you can see is always the acoustically active area of the loudspeaker - this is true for practically all other drive units. By folding the A.R.T. diaphragm into the third dimension as seen from the listener's position a much larger folio can be used. A factor of more than 2.5 can be seen between the sound generating area and the acoustically effective area of the diaphragm. Thus a smaller movement is needed for a given sound pressure level, enabling the unit to reach a higher sound pressure level without dynamic compression. To improve the reproduction in the middle frequencies the A.R.T. Midrange Unit has been designed. The same principle is applied, however by using different sizes in geometry, width and depth of the folds as well as in diaphragm thickness; frequency response here starts at 300 Hz. To avoid resonances in the most critical midband area the unit is housed in its own small cabinet that is acoustically decoupled by "floating" on a damping foam within the main cabinet. Exact transient reproduction and spatial information are the benefits of this approach. The air gap in this unit has an enormous volume compared to comparable voice coil based systems. 28 neodyme magnets of the highest strength available are used to get the efficiency needed for good overall performance. This costly decision pays off however with the unsurpassed clarity and fidelity achieved by this unit.
