Please have a read through THIS post and look at my instructions.  I had some difficulties initially getting the ST 300 setup using ARC with my Samsung TV and the key to getting it all setup was to do a factory reset through the remote.  One word of caution:  a member brought up a good point with this process which was that they'd had their TV professionally calibrated and doing the reset would wipe out those settings.  Needless to say it wasn't an option for them.  In my case, it was not an issue.  All has been working well with my ARC connection for 7-8 months with an occasional hiccup.  ... View more

Actually my issue was unrelated to the OP's original one.  My point was that by contacting Bose Tech support, the issue I did have at the time was quickly resolved.  I'm certain that not all issues can be resolved as quickly, but it is always worth a shot IMHO to contact customer support when issues arise.  Apologies for the confusion. ... View more

Up until this latest update, I had to use the Cable box connection to HDMI IN on the ST 300 and OUT to ARC on my Samsung TV in order to get ARC to work and to ensure the source did not switch.  Once the update was applied, I did the following:   1. Disconnect power from all devices connected to TV. 2. Disconnect all HDMI cables on both ends of devices. 3. Apply power to all devices 4. Service reset of Samsung TV  Before beginning, it's very important to make sure that your TV is OFF. Take your Smart Remote in hand and simultaneously press Info + Menu + Mute + Power. Next, enter the following sequence into your remote: Mute > 1 > 8 > 2 > Power. Your television will boot up in service mode. Using your remote, go to Options > Factory Reset. Your television will now turn off. Simply turn your device back on to proceed with the setup   This resets all settings on your TV to factory default and is different than going through the settings in software and resetting your TV.  You will need to apply any settings, calibrations, etc.    5.  Power off TV and make HDMI Connections.   On my TV I have the Samsung Instant On turned OFF, Anynet+ HDMI-CEC turned ON, Auto Turn Off NO   In the ST APP, I have HDMI IN direct Audio turned off, HDMI-CEC set to Alternate ON.    I am now able to use ARC directly from the ST 300 to the TV without routing through the cable box.  This is a first, so at least in my case, this updates seems to have worked as Bose had hoped it would.  It has worked flawlessly.  I recognize that different brands of TV's and even different TV's in general within the same brand aren't necessarily displaying the same issues, but you might give this a try in hopes that it works for you.  The key to all of this is the SERVICE reset I described.  I should note that I was given this direction by @Bjoern Hirsch.  His work with Samsung deserves credit for this find. ... View more

When you open the App, there are the 3 lines in the top left corner.  Look at Settings>Speaker Settings.  You should then see your speaker. select that, then Advanced Setup> HDMI IN Direct Audio.  Towards the bottom you will see the delay setting.  Obviously you have to enable this feature first which may introduce other issues but it is worth trying.    It'd be helpful if you mentioned what products you're trying to connect.  Have you tried adjusting the sound settings on the TV itself?  There could be a setting for sound delay there.  ... View more

Out of curiosity, have you tried adjusting the settings within the TV's sound settings, or attempted to adjust the controls under the advanced speaker settings>HDMI In Direct Audo settings in the Bose App?    I won't make excuses for the mods, I too had a post that went unanswered and understand your frustration. I contacted Bose Tech Support today via phone and was able to get my issue resolved, you might consider reaching out that way before returning unless you're completely set on doing so.  ... View more