There are three things you can do to improve TV sound quality:
1) get a good toslink, like:
http://best-tronics.com/mm5/merchant.mvc?Screen=PROD&Store_Code=BMI&Product_Code=TOSLINK-XXX&Category_Code=TOSLINK
or
2) use a Roku 3 to make it a smart TV (to watch Amazon) and add a HDMI audio extractor like:
Kanex Pro HAECOAX
or
3) Get an Oppo Blu-ray player to make it a smart TV and watch VUDU movies. Use the coax out or the DAC inside the Oppo
#3 is the best quality. Forget Netflix. Bad video and audio quality on most devices. Use VUDU and Amazon.
Steve N.
Empirical Audio