I had a same problem. My rear channel was never strong. After I changed the dealer, I learned that this particular rear amp is problematic. I still have the amp, but I no longer use it for surround sound, I bought another one and kept harman kardon in my bed room. Sorry.
Harman Kardon AVR85
Hi I have a Harman Kardon AVR 85 and BOSE AM15 with a Sony DVPC600 DVD player. I find that my surround channels (back speakers) are not giving me a good output. There is setup involved in AVR85 (am choosing small speakers) and in DVD (again small speakers) that i did but inn all the modes prologic,hall,matrix,movie,3stereo and stereo I get a very low output when i play from my DVD player. Is there some thing that i need to setup to get good effect Thanks in advance Vijay