Check your level settings and make sure you have not inadvertently left any muting on. There is no way I can withstand the SPL with the 3805's volume at -10 let alone +0.5 when playing CD, DVD or tuner. Watching TV is a different story as some channels are louder than others.
If all else fail, try resetting the unit to factory default conditions. If you don't know how just read the manual, or let us know.