Originally Posted by PeterCat
According to Yamaha the 473's YPAO just calibrates for speaker distance and there is only one PEQ to choice. With the 673's YPAO it has the RSC (reflective sound control) and also gives you three different PEQ's to choose from: flat, front, and natural. I don't know how much of a difference the RSC feature will make, but I've got an acoustically challenged room and I'm willing to give it a shot. I've read through both the 473 and 673's manuals and the 673 has more customization ability throughout its features.
I have a 773, and I'll tell you something I really like about the YPAO options (similar to those on the 673). As stated, you get three options in Flat, Front, and Natural. Natural really rolls off the highs on my Polk speakers, resulting in a sound that isn't overly bright. In fact, with TV source material, especially music channels, the sound feels a little lacking. Flat sounds better, but I still wanted to open it up a bit so I copied Flat to the manual settings and brought the mids and highs up a bit more. This brings that TV music sound, which seems to have less DR and muted highs, to life a bit better.
With recorded material, even MP3's, the story is different. At higher volumes the Flat and my manual tweaks are much brighter sounding, possibly fatiguing. For this, the YPAO Natural settings works quite well. That's what I'd probably use at a party, where people might not like to have the tweeters screaming at them all night. I really like having these options for different sources and situations, and I like that I can tweak the YPAO settings directly, or copy them to Manual and tweak them there.
I am by no means an audiophile, yet I can really tell the difference between the settings and I can appreciate the option to use different settings for different material and input sources.