List the make and model number of all connected devices. Advise speaker wire details - size and length of runs from receiver.
How loud do you listen to the system? Do you hear any distortion approaching this level? Speaker locations in the room relative to your primary listening spot can also be helpful. Are they in corners, near a wall, etc. (Diagrams or photos can help here.) Source material - CDs, Vinyl, Streaming, Blu-rays, TV, etc.