I have a VERY high end home theatre set up ($25K plasma display and $2K surround sound bar) and my audio uses Toslink optical digital, with no way to get audio directly from an HDMI cable so i thought i wouldn't be able to use the Apple TV4 since it has no optical digital audio output. but it was easy and inexpensive to do. all you need to do is get an extractor. The big question is whether the video and audio will sync properly when you use an extractor. i got the J-link extractor from Amazon for $31. and when i ordered the Apple TV4, i also bought the HDMI to HDMI cable ($19) from Apple. Initially, the audio was a total mess but it only took me about 5 minutes with the help of apple tech (i've been using Apple since 1984 and i ALWAYS get Applecare with all of my many Apple products - not fjust or repairs because i've hardly ever needed that - but becuase the tech support is absolutely superb. they will stay with you on the phone for as long as it takes to resolve your problem and if a particuar tech can't help, you get passed along to higher level techs until you get one who can help also, it is easy to sell my apple products when i upgrade becuase the Applecare goes with the product which gives the buyer confidence that hes not getting a dysfunctional product and if it does fail, Applecare will take care of it). It took a minute or two of making audio setting adjustments on the Apple TV4 and i found that setting the audio on the Apple TV4 to 16 bit and to Dolby surround sound worked (others may use other settings, depending on their audio system). The sync works perfectly with iTunes shows and also with Netflix and with YouTube; that's all i've used so far (and Airplay works perfectly as well when i used Amazon video and Acorn TV from my Macbook air). One note - Apple, rather stupidy IMO, sells the remote strap separately from the Apple TV so if you want one, you need to order it (i'm disabled and i don't play games but the strap keeps me from losing the remote (why do they make them so small?). also, i was initally not happy that the remote control app on my iPhone doesn't work with the Apple TV4 because i liked the keyboard for making entries doing searches (my hands don't work well due to my disability). but the entry on the Apple TV4 remote is reallyeasy to use. oh and the original set up is incredible. i just turned on bluetooth on my iPhone, held it 6" from the Apple TV4 and it correctly set up by itself the router name and password. finally, my video using the Apple TV4 is much better than it was with the apple TV3. i give this product a solid A grade.