I have three Vizo TVs (all 5 or more years old) - 1) M370NV with DC50x cable box 2) M260VAW with DC50x cable box and 3) M470NV with DCT700 cable box. The first two TVs do not have bluetooth on board so I wanted to add bluetooth. I went with a "Miccus Home RTX Mini: Bluetooth Transmitter or Receiver with TOSLINK" because I needed a transmitter that could use the optical out on the TV.
My headphones pair with good quality sound to the Miccus when I use a Roku feed to all TVs. With the cable feed only the M470NV provides a great output; the other two TVs provide the sound of a loud, dull beat or thump and no audio from the TV.
The M370NV also has L/R audio out so I tried this output by cabling the L/R into an audio jack (AUX) on the Miccus and the sound from the M370NV came through perfectly. Unfortunately the M260VAW does not have the L/R audio out so I am stuck with optical out. The M260VAW is, unfortunately, the one I need the bluetooth for the most. I don't want to use the headphone jack on the TV because it would turn off the sound. I want something I can permanently plug, again pretty well limiting me to the optical out.
I thought the problem was the DC50x since the behavior was on the two TVs with this cable box. I went to the local Xfinity store and told them the problem. They gave me a Motorola DCH70 to take home and try. After activation, I used the DCH70 on all three TVs. The behavior was the same. Only the optical out on the M470NV was working on the Comcast cable feed and all three worked on the Roku feed. (At all times I left the M470NV's internal bluetooth off and made sure the connection was only to the Miccus.) (Using the DTC700 on the two TVs also doesn't work.)
I would think that there was something wrong with the optical out on the TVs that wouldn't output the Comcast cable audio if the Roku audio were not perfect using the same output.
Any ideas on what makes the Comcast audio optical out different from the Roku?