Processor Upgrade from Onkyo 885

Looking to upgrade from the Onkyo. Budget around $1,500 used. Still not that many processors that decode the hi-def sound formats and those that do are expensive so that is not a necessity. Will be used with the Oppo BD SE machine and Proceed AMP 5.
what are you hoping to gain by "upgrading"\? Other than the brand name, what doesn't it do that you need and would like it to do?
Dialogue is not as clear and concise as I would like.
Having owned the 875 I can tell you it is a swell unit. Might be your speakers or speaker wire. Onkyo makes great SS receivers in spite of the price. In the price category they are the best to me.
I too would bet on your speakers and room acoustics...however the audyssey processing in that unit should provide excellent correction, assuming you're using it and set it up correctly.

Keep in mind that the 5:1 audio sent with HDTV signals is not always wonderful (to say the least). Often the stereo signal is actually better.

Have you tried reversing the polarity on your center channel speaker? Sometimes this makes a big difference.

I doubt that replacing the processor will fix your perceived problem.
I have the Onkyo 876 that mated witht the Mirage speakers and I also have the Pio SC05 with the Def Tech SM45/ CLR2002, I do not see how the dialogue can be any better than what I have. So, I stop looking to upgrade my H/T and use the $$$ for purchasing the BR movie collection.