I think, having owned RV-NB 10 that the sound quality, not necessarily the bass or the volume, but the quality is just so much better and cleaner. I mean the NB 10 was a monster with its bass and such, but the ACS was crap and none of the other settings got it right unless you wanted to listen to Rap or R&B and wanted that much bass. Anyone agree? I like the old ones still. just feel the sound has been refined with this one for sure. It would be nice if wer had a side by side comparison, too