Originally Posted by kikkenit2
Arc and toslink in theory have the same bandwidth. It mostly comes
down to how the tv handles built-in audio and pass through audio. Even
among Samsung tv's the audio passing skills varies. I see a trend.
Older tv's had better output over toslink and now that is being
reversed to arc having better audio formats/quality. Doesn't
netflix allow an audio stream of dd? If not they are using a dd+
bandwidth lower than dd. It may even come down to your internet
connection speed. Doesn't the video take up most of the bandwidth anyway?
Bandwidth isn't the issue, I've tested that. I have roughly 58mbps down, and did when I did some testing.
I did comparison streaming of the same movie, same scene via the Samsung TV, Panasonic Blu-ray player, and a Chromecast. Netflix identified that their audio stream choices were DD+ and DD 2.0 PCM. On both the BD and the Chromecast (connected via HDMI), my AVR registered output as Dolby Digital+. From the Samsung TV, the AVR identified it as DD, so the TV was clearly down-converting the audio stream. (At least, I think
I remember the BDT-215's output as DD+. Dropouts didn't happen, though.)
(Clarification: according to an article, the DD aka AC-3 audio stream is embedded in the E-AC-3 stream, so equipment need only extract it for backwards compatibility. No transcoding needed, it seems. )
My reading on Dolby's site and elsewhere indicated that DD+'s strength is backward compatibility with equipment that can decode DD. The weak link in my case appeared to be Samsung. I thought I recall other forum authorities (here, Home Theater Forum) pronouncing the DD/PCM 2.0 limitation of SPDIF output methods.
Further information (not necessarily authoritative, as wikis are wikis):