I audited Image 15 before.The sound is much much better then Alpha B1.This my own preference.I heard alot said NAD315BEE + Alpha B1 is quite good but i didnt feel any special at all.Only feel nice when Image B15 combined.The sound is like more out especially the vocal.It using more tweeter power.And the intrument sound is out of the speaker.

Btw how u feel the B25 .Good ? I audited B15 from there as well.I feel B15 is much better then the B1