Why Do I Hear Static When I Stream Netflix or Vudu Movies?
Q I want to get better sound when watching movies on my new Panasonic ZT60 plasma TV. (I stream a lot of Netflix and Vudu via the Panasonic’s built-in apps.) To that end, I recently bought a small stereo setup: an NAD C326BEE integrated amp, a Musical Fidelity V90 DAC, and a pair of Monitor Audio Apex 10 speakers. The only way to connect the TV to my audio system is by using an optical digital output from the Panasonic to the DAC, which then connects to one of the NAD’s stereo RCA inputs. Here’s the problem I’ve been having: When I watch Netflix or Vudu, I hear nothing but static noise coming from the speakers, though the sound is fine when I watch DirecTV (I have my satellite receiver connected directly to the TV via HDMI). This noise went away when I switched from 5.1 to 2.0 audio in Netflix, but I don’t get the same option for Vudu. I’m kinda stumped at this point. Shouldn’t the Musical Fidelity DAC automatically dumb down 5.1 signals to stereo? Is there another possible configuration that can solve my problem? —Gilbert Solis / via e-mail
A Yes there is, and it should be an easy fix. The reason you’re hearing static noise when you stream movies is that your Panasonic TV is currently set up to route a raw Dolby Digital bitstream through to the Musical Fidelity DAC. However, standalone stereo DACs like the V90 lack the same Dolby Digital decoding capability found in surround sound processors and AV receivers; the optical digital input will only accept a stereo PCM digital signal. Your DAC might not be capable of “dumbing down” multichannel soundtracks to stereo, but your Panasonic TV is. To set up the system correctly, select the TV’s digital audio out setting in its audio setup menu and switch the output option from Auto to PCM. That will force the TV to convert Dolby Digital soundtracks from Netflix and Vudu movies to a stereo PCM digital signal that your DAC can work with. (Since you’re not having the same noise issue with DirecTV, I’m guessing that your satellite receiver is already configured to output stereo PCM audio signals, which are passed on unchanged when the TV’s Auto digital output option is selected.)