I had an issue with my bluray player and getting decent bass with the 6 channel audio. I emailed Harman Kardon tech support to see if the issue was with the receiver and even though the tech rep did not know for sure where the issue was, he offered to replace it "just in case". I fixed the issue with help from these forums so I don't need to replace it, but just because they offered I will be a Harman Kardon customer for life!! (Not that I will need a new receiver any time soon).