Armando, I had the crackling sound on Dolby prologic mode as well. It was my punishment for trusting Volvo to know how to build a quality system that I paid $1,000 extra for. Oh, I forgot, maybe my punishment was that all my CDs got stuck in it. Or was it the car's clunks/clanks/clops etc.?

As for the crackling, the dealer varied from telling me "it's normal" to telling me "it doesn't exist". At this point, I can look back and find the whole thing almost comical. The crackle was intermittent, so it's not always easy to demonstrate to the dealer. Over the past year, others have had this problem, and I wonder whether there might be a TSB out on this. I think I read somewhere that a replacement "head unit" may be a fix, but I'm really not sure- others may know. Thankfully, I didn't keep the car long enough to find out. As for your perception of increased power for the 2001 S80, I am not aware of any changes in the specs to account for this. What kind of octane rating are you using in your car?, ?maybe your air filter needs to be changed, ? whether your tire pressure is OK.

Good luck with the crackles. My guess is that a good dealer will be familiar with this and should be able to get it fixed.