I recently just purchased a pair of Ascend Acoustics cbm170 and a Denon 1613 receiver. I play music by airplay with Airfoil. After a few days, I heard hissing sound. It's especially obvious with piano records and classical female vocal, and sometimes the clipping/hissing gets louder as the music gets louder. When I play pop songs, I can't hear the clipping/hissing at all. I tried to connect my iPhone to it by usb, playing the same song, and it had much less hissing. I also tried to listen to the song with my headphone, and it didn't make any hiss.
When I don't play music there's no hissing.
I tried to change my gain to 30%, but it didn't make it any better. I am very confused. Please help me!!