1. How can one hear the difference between the Concert Grand SA voice on Tyros4 and the Concert Grand Live voice on Tyros3? Some posters claimed they could not hear a difference.

2. How does one access the SA features of the piano voice?

3. In using the TRSMS04 Yamaha speakers for Tyros4 should one set the keyboard volume on maximum (and adjust the room volume using the volume control on the speakers) or should the keyboard volume be set relatively low (and increase the room volume by increasing the volume control on the speakers)?