Hi Letor,
I have an 8.1 and was able to listen to 9.1 at sights and sounds (Shangrila). Based on my few minutes of listening to the 9.1, the most noticable difference between the two is in the bass region. The 9.1 has more bass than the 8.1. The mid and high section is almost the same. Maybe the 9.0 will be equivalent to the 8.1 (haven't listened to the 9.0 though) but the 9.1 is, for me, better than 8.1. To add to that, the 9.1 is already product of the year sa What HiFi magazine. Now, I'm seriously considering the 9.1 as against to my earlier preference, the 9.6 Just my opinion.
losi_phile
Finally i got a chance to test the 9.1 vs the 8.1. Using the same rotel amp and music:
Observations:
D9.1:Better bass response (+factor)
Fast transient response (+factor)
More spacious soundstage than 8.1 (+factor)
Vocals quite thinner compared to 8.1 (- factor)
The 8.1 has a warmer and natural vocal sound especially male voices.
Conclusion:
D9.1 - good for instrumentals and instrumental jazz music
D8.1 - good for music with emphasis on vocals.
just my observation.