Lol. Lets get this sorted. It seems like a clipping issue in your chain or you are clipping your amp.

Can you walk us through your signal chain. What are the items below in your setup.

Source—->Preamp—->Amplifier——>Speakers

what is your preamp output, or in the case of an AVR trim level set at.

Next we will ask what is your amplifier input sensitivity, or in the case of an AVR what volume is the dial at?