The X-ART Technology
The X-ART (eXtended Accelerating Ribbon Technology) tweeters and midranges incorporate a new approach to the Air Motion Transformer concept originally developed by Dr. Oskar Heil. ADAM Audio has improved upon this splendid idea utilizing superior geometries and materials to achieve unprecedented audio fidelity. X-ART strikes a new path concerning the kinematics of moving air, resulting in a dramatic improvement in the quality of audio reproduction.
The X-ART membrane consists of a pleated diaphragm in which the folds compress or expand according to the audio signal applied to them. The result is that air is drawn in and squeezed out, like the bellows of an accordion.
The ADAM X-ART design overcomes the piston-like motion of all conventional drivers and their inevitable problems (see previous page) by achieving an improvement in air loading by a factor of 4 over conventional transducers. To illustrate the basic principle by a comparison: When you breathe, your thorax is moving slowly whereas the air is moving comparably fast. Similarly, the X-ART diaphragm presses the air faster in or out of its folds than they themselves are moving. This markedly superior ”motor” is responsible for the unprecedented clarity and pristine transient reproduction that can be heard with the ADAM X-ART drive units.
In addition, the X-ART tweeter’s pleated membrane avoids the typical breakup/distortion and subsequent dynamic limiting at higher frequencies of stiffer voice coil designs, such as those found in dome and cone tweeters. Another positive result of the X-ART design is that the driving ”stripes” are in direct contact with the outer air and are cooled immediately.
Fig. 1: X-ART tweeter impedance: linear within ± 15 mΩ (green) in comparison to a 1” dome tweeter (red)
Fig. 2: Phase response of the X-ART tweeter compared to a 1” dome tweeter
Fig. 3: Unfiltered X-ART tweeter with microphone position in 0°
More area = more dynamic
Diaphragm area is another important factor in determining the dynamic range of a transducer. Basically, 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 X-ART diaphragm into the 3rd dimension (as seen from the listener’s position) a larger foil can be used, thus increasing the acoustically effective area of the diaphragm by a factor of more than 2.5 times. This results in higher dynamic output with extremely wide dispersion.
"...an excellent piece of craftsmanship..."
Audio Media was amongst the first magazines to review a new SX-Series model. About the tweeter they say:
"The famous ART tweeter as used in ADAM’s monitors has also undergone reconstruction in the X model providing 4dB higher efficiency and reproducing frequencies accurately all the way to 50kHz, which has made such a difference. The ART tweeter from ADAM has always been one of its strong points, but this new X-ART tweeter is a perfect balance in what is an excellent piece of craftsmanship. "
(Audio Media, 09/2009)
Fig. 4: The X-ART Principle: moving the air in a 4:1 ratio
Fig. 5: Area comparison between the unfolded X-ART tweeter diaphragm and a 1” dome tweeter