I recently purchased this receiver and have it hook up with the 5.1 kef 2005 speakers. I have to turn the volume to max in order to hear ok sound. (but not consider to be loud) Sent it for repair thinking somthing is wrong. They said everything is fine and that's how denon receivers are. I also tried a different set of speakers (JBL) to test, and same thing happen. Please advise how i can get louder sound. Thank you much.