Checking the bass, treble and loudness settings are a good idea. If they are up high they can be causing a problem. When properly setup i doubt there is much of a difference. A lot of people like the 880prs and I know atleast one person who has won sq competions with the 860mp. I think changing the deck would be a waste of money that would be better spent on either speakers or an amp. Its not like were talking about an all out competition sq car (no offense to 88'crx).