In my struggle to find a good reason to upgrade from my 4311 to a 4520, I've stumbled on another cool feature, which is DTS Neo:x 11-channel music mode.
I have a large collection of music concerts and I often like to listen to them with Audyssey DSX 11-channels. DSX gives the impression that you are in a huge room, with artificial reflections coming from the wide and height speakers. The "sound envelopment" is pretty severe and you feel literally surrounded by the music. I find this very good for opera, orchestra and some types of broadway productions (such as Phantom of the Opera).
DTS Neo:x 11-channel music is more front-centric so it sounds like you are in a smaller room, maybe a jazz bar, instead of a grand opera house. For a lot of jazz and pop concerts, I like it a lot better than DSX.
I haven't experimented with movies yet. That would be my next experiment.
Has anyone experienced something similar with DTS Neo vs. Audyssey DSX?
I decided to offer my opinion regarding the various choices on the 4520 for listening to music. I was listening to Tift Merritt's Buckingham Solution (Live) 2ch recording (very clean and acoustic, with vocals, piano or guitar accompaniment, and audience sounds). One nice thing about holding down the Music key on the 4520 is that you can cycle through the various modes, getting a quick snippet of how the music sounds in each mode. Unfortunately, it's not a very long snippet, but since audio memory is short as well, being able to quickly compare is actually quite revealing.
I listened to stereo, PLIIx Music, PLIIz, DSX (wides, heights, and wides+heights), and Neo:x. My impressions:
Stereo: incredibly center-focused and intimate (my LR speakers are exactly equidistant, so the stereo image is quite centered). Very little ambiance, no sense of being in a concert hall.
PLIIx Music: opens up the performance with a nice amount of ambiance. Vocals still dead center. Overall, very pleasing.
PLIIz: adds some recognizable height information, but seems to pinch the vocals into the center. Not my favorite mode.
DSX Wides: adds breadth and ambiance. Closer to a concert hall sound. Less intimate.
DSX Heights: best concert hall ambience, IMO. If I want more ambiance, this would be my preferred mode.
DSX Wides + Heights: too overwhelming. Sounds coming from the width and from the ceiling. Not natural sounding to me.
Neo:x: almost sounds like stereo to me, with vocals pinched into the center. IMO, little concert ambience. Quickly switching between stereo and Neo:x, I preferred stereo, and distinctly disliked the latter. Sorry to disappoint.
Conclusions: My first choice, and the default setting in my QuickSelect, is PLIIx Music (actually PLII Music, but I can't figure out how to toggle the rear surrounds off). Second choice would be either Stereo, or DSX Heights, depending on the type of music. I never use any of the other music modes. And by the way, for Multi-channel music, I prefer the unaltered Multi-channel In, with no DSX processing.