Sony NS999ES coax problem


I have the 999ES and a transparent premium digital cable connected to my receiver as well as two transparent super xl innerconnects hooked to the audio out L and R. When wathcing a DVD and using the DVD mode on the receiver the sound is very low and shallow. When I switch to CD mode and don't use the coax, it sounds much better. Have I done something wrong?
bravadoscdab
I would check the setting . Is it analog or digital on the setup on the receiver and the out put setting on sony?
ON THE DVD IT SAYS DIGITAL OUT, AND THE RECEIVER HAS THREE OR FOUR PLACES TO PUT DIGITAL AND THEY ARE MARKED COAXIAL