Top critical review
Same design flaw as prior models; DO NOT BUY if you have a multi-speaker AV setup.
Reviewed in the United States on October 9, 2021
I pre-ordered this device in a final Hail-Mary that maybe, just maybe, Amazon had finally produced a device that actually works the way it's supposed to. Alas...
The Fire Stick 4K and the 3rd-gen Fire Stick both have a design flaw that affects users of multi-channel surround-sound receivers. When "Surround Sound" is set to "Best Available," the device sends stereo content (from, e.g., live TV) to the receiver not in 2-channel PCM, but in a 5-channel "wrapper" with sound on the front left and right speakers and silence on the other three. This prevents the receiver from processing the pass-through signal into 5.1-channel pseudo-surround using, e.g., Dolby ProLogic II. The only workaround is to set "Surround Sound" to "Dolby Digital," which has the side effect of downgrading Dolby Digital Plus content (from, e.g., Netflix or Prime Video) to the lower-resolution legacy format.
So, the user has three choices: (1) sacrifice the receiver's surround-sound processing capability for stereo content; (2) sacrifice the higher-fidelity DD+ for multi-channel content, or (3) cycle through the menus (Home -> Settings -> Display & Sounds -> Audio -> Surround Sound -> ... ) each time and change the setting to actually get the desired sound mode. Or, the user can use one device for live TV and other stereo content, a second device for multi-channel content, and switch between devices (and remotes) each time to get the same effect.
This has been a known issue with the Fire Stick 4K for three years, discussed in the product forums, yet it never shows up in any independent reviews of these devices. My hope, obviously, was that Amazon had addressed and fixed it for the new 4K Max; I even contacted Amazon Support before pre-ordering to describe the foregoing design flaw and ask specifically if the new device would have it as well. I was assured -- twice -- that it didn't. It does. Not only has Amazon buried its head in the sand, it has purposefully built this same design flaw into two more devices: the 3rd-gen Fire Stick, and now the 4K Max.
To my knowledge, no other manufacturer's streaming devices have this problem, viz., require the user to jump through all these hoops to get DD+ surround and PL-II surround from all sources, or else do without one or the other. Every non-Amazon streaming device I have used sends stereo content to the receiver in 2-channel PCM (as does the 2nd-gen Fire Stick), and multi-channel content in DD+ where available; i.e., the pass-through audio works exactly the way it's supposed to.
Obviously this was the first thing I checked so I didn't bother to evaluate the device's other features and performance before it went right back in the box to be returned. If you don't use a separate sound system this device may work for you; I have no idea how it works with a soundbar but if you have a multi-channel surround receiver/speaker system, stay away from this and other Fire TV devices.
I think this is it for me as far as Amazon devices go; every one I've bought has at least one annoying glitch like this, each more disappointing and exasperating than the last, and their tech-support associates either don't have a clue or flat-out lie. It's been a frustrating experience to say the least.