The ATX-3 system is found on our 45″ K200-ATX3 AnyTime Piano. It features our new SK-EX Rendering Piano Sound Engine with Multi-Channel Sampling, a 5” LCD Touchscreen Display, Integrated Bluetooth MIDI and audio wireless technology. The digital sound and the touchscreen user interface are first-rate in this instrument. Of course, the acoustic tone is also exceptional — and just what one would expect from a K-200 Professional Upright. The AURES system is found on the 48″ K300 Aures. So, the 3″ additional height is the first difference from 45″ K200-ATX3. The AURES features our new “Hybrid Sound Board” amplification system featuring 4 high-end performance transducers designed by Onkyo. When the digital piano side of K300 AURES is played, the digital sound is produced entirely by the wooden soundboard activated by the Onkyo transducers. This creates a fuller, more immersive tone quality. It actually “blurs the line” between acoustic and digital sound because both are emanating from the same sound board.