Originally Posted by Krutsch
If I could be sure that the problem is between my Apple TV and my router, that would be a solution... I am not convinced that the problem isn't from the source device, as well (e.g. iPhone or MacBook Pro).
Besides, I don't see where I can plug an ethernet cable into my iPhone
Ditto the iPad, but that's not the point. The point is to get everything wired other than the iPad/iPhone, where there is no other option. Otherwise, AirPlay is doing one wireless hop from the iPhone to the router, and then another wireless hop right back out to the ATV... two simultaneous wireless hops, running continuously. Perfect recipe for issues.
Wire everything except the iPhone (or iPad) and it's just the one hop, iPhone to router, and then wired for the rest of the trip. No rebroadcast. MUST more reliable. Don't believe me? Read this entire thread, followed by the support threads at Apple, followed by the support threads on any other forum on this issue... you get MUCH more reliable performance when the only thing that is wireless is the iPhone/iPad. Same applies if a wireless MBP is your source... one extra hop from the router to the ATV really messes with things. Wire up that ATV/AEX!
To maintain the best AQ and PQ, Apple Streams a very high bitrate losslessly compressed audio stream to the ATV (or AEX). The conversion to high bitrate (if needed) is done on the client side, and then streamed as a really fat ALAC (Apple Losseless, like FLAC) stream. So it hits the wireless bandwidth pretty hard, even if you're just streaming a low quality MP3. Best to only have one wireless hop, if any, in the chain.