I have a Pioneer vsx-815 reciever and have a digital Rca running from my dvd player to the reciever. It plays sound good when i choose dolby digital 5.1 sound off the dvd menu but when i choose the 5.1 dts i get no sound and my reciever doesn't even indicate a Dts signal.Could this be because i only have 5 speakers and not the sub-woofer? if not then why?
It is more than likely your DVD player. You have to set it up properly.
Go to the set-up menu and make sure that there is no disc in the tray.
Go to the Audio Options and check out the output. Make sure that the DTS option is toggled "ON". Check your manual for specifics on how this is turned on.
Is your DVD player capable of DTS output? If not, then that's a different problem all together.