Digital Audio Denmark's high-end AD/DA converter, the ADDA 2402 is, the company claims, the only converter on the market which is not affected by Aliasing Intermodulation Distortion - an 'invisible' distortion which affects digital audio equipment. Aliasing Distortion normally appears between 20 - 22.05 kHz (at 44.1 kHz sampling) and by itself is inaudible. However, a recent study by independent consultant Richard Black has shown that these a-harmonic frequencies intermodulate with the frequencies in the audible band and create new audible a-harmonic frequencies when reproduced in loudspeakers. Richard Black has made a CD recording to demonstrate Aliasing Distortion, and can be contacted via e-mail: 100115.3701@compuserve.com
