Which model Yamaha do you have? What speakers are you using? Do you use a sub? YPAO sounds fine to me. When I ran it, it set my speakers to large so I just changed them to Small and use a 60hz crossover to the sub. when I go back and forth between YPAO and No YPAO "Through" setting, YPAO sounds better to me. Imaging is better, the music just seems clearer and more focused, if that makes sense. YPAO volume is designed for times when you want to listen at lower volumes. I have not measured, but it seems to boost the midbass or midrange frequencies a bit for sure.