That receiver is very "tweakable." You can actually get the STRDE 925 to sound very good, but it could take weeks. It has a decent power supply and amp, believe it or not. It will overheat, so keep it ventilated.
I had helped a bunch of guys a few years back with a perfect eq setting on that thing. It really brought the speakers to life.
First off, get a tape measure and set the distances from your seated position. Next, set the crossover to 80Hz (Im trying to remember this stuff). Then what I recommend you do is get your favorite cd, sit down with your lcd remote (it has a killer remote), and play with the eq settings. Try the bass at 100Hz, the midrange at 1000Hz, and the treble at 4000Hz. boost them all the way, then cut them back to your preference. Do all this while listening to your favorite cd. Oh - and don't turn on the sub until you get your two front speakers sounding perfect. Once you get them dialed in, repeat the eq settings for the center and surrounds. Only then would I add the subwoofer. Much easier to add the sub after the rest of the system is complete.
The Avia disc does much of this for you, but it sets things flat. Many prefer peaks and valleys depending on preference/type of music. That's what makes that flexible Sony so nice.