WDTV GEN1 with HDMI + RCA

Hi I have a question to ask.

I have My WDTV connected to my TV using HDMI the sound works fine except for DTS on MKV.

is it possible to use an RCA cable to connect to my Home Theatre to get DTS surround sound? or is it soley available through TOS link?

My HT supports DTS by the way

TV=SONY KDL-46V4000, HT=SONY DAV-DZ111