[Fire TV General] harlekinwashere:
Bluetooth audio can lag for up to one second behind the actual content.

It seems to vary with different devices, but it definitely is an issue.

Sadly its one thats hard to rule out before you buy a headset - because people like what they bought. I just googled sennheiser's momentum 2 and latency - and you get mixed reports. Some people say aptx (which the firetv doesnt support) is causing the issue - some say it is solving it... Some say there is no issue at all...

So worst case scenario is, that you move through five different headphones and find, that the audio lag is still unbearable.

Thats why people usualy go for RF Headphones in that szenario. That said - RF hadphones need an audio jack and the Amazon Fire TV (/Stick) devices don't have any in their current iterations. So you would plug them into the Audio jack of your TV instead - if the TV has one.

Wirecutter has a new article on them - but I dont agree with the verdict.

h**p://thewirecutter.c*m/reviews/best-wireless-home-theater-headphones/

I like open headphones better than closed ones for pretty much any purpose - so I like the RS 120 II's better than the RS 160 or the RS 165. I havent tried the RS185s. I measured both the RS 120s and RS 160s (which I own) and can tell you that they show the same spike at 4Khz - so when the reviewers complained about some hiss on s sounds, they suddenly liked that on the RS160, I guess - I've never found it to be an issue at all for TV listening. In fact I like it that both of those headphones tend to heighten the mids a little. The RS120 has much less bass - but I actually prefer that as well in most situations, because your ears dont get tired listening to the headphons as soon. Long story short - I very much like the RS 120 IIs (not for music listening, but for watching TV).

If you go the bluetooth route - please report back - id be interested in some additional findings about the usual latencay. When I paired BT speakers with my Fire TV, sound always lagged considerably.

---------- Post added at 07:43 AM ---------- Previous post was at 07:21 AM ----------

Found a bit more usable information. Curiously on a manufacturers website.

h**ps://sennheiserusa.happyfox.c*m/kb/article/108-why-is-there-an-audio-delay-when-using-a-bluetooth-dongle

The A2DP protocol adds a latency of 120ms - which is too much for watching TV. Certain BT devices and headphones thereby switch protocols for phone calls (they then use HFP which is a very low quality audio transmission protocol). I'd guess, that the Fire TV (Stick) will not do that.

So analog to those findings I am willing to believe that aptX would solve those issues, but none of the Fire TV devices supports it.

Hence - there will be lag if you don't go the RF route. The Fire TV (/Stick) will be using the A2DP codec.

---------- Post added at 07:57 AM ---------- Previous post was at 07:43 AM ----------

edit 2: Turns out the issue also has an android specific angle:

h**p://www.androidpolice.c*m/2015/11/13/android-audio-latency-in-depth-its-getting-better-especially-with-the-nexus-5x-and-6p/

You might be able to live with a 50ms+ delay - or you might not... :) But 50ms+120ms (A2DP) will be a a bit much in the end... :) You can easily gage how much of a delay there is (or how it would sound like if there was :) ) by using the audio delay compensation settings in Kodi. But in the long term always using Kodi to compensate for it isn't ideal and very bothersome.