Apple Dolby Atmos, JBL Synthesis, I'm not crazy...? (1 Viewer)

[Leaky2014]

I've noticed that when playing certain songs from my iPhone (11 Pro Max) through Bluetooth that the songs that have Dolby Atmos, very few do, that there is a huge noticeable difference, especially with the lows.
So here is the setup, 2014 LC w/JBL Synthesis stock system.
iPhone, sending signal via Bluetooth, song downloaded to phone, in Music settings, Dolby Atmos > Always On EQ > Off Sound Check > On Download in Dolby Atmos > On. Lossless Audio > ON
Stereo Setting(JBL), high mids and lows all to the right. DSP on or off doesn't seem to affect the lows but does make highs seem to float around more if on, especially when Dolby Atmos is set to Always On.

Now I don't think it's actually playing to Dolby Atmos however when playing the song file I have switched the Dolby Atmos setting from Always On to Off and from Off to ON and it changes, dramatically on certain songs.
So what is the deal?
When you download the Dolby Atmos version of a song it also downloads the "normal" stereo version, for incompatible devices, so in theory since the JBL system isn't Dolby Atmos compatible it should be playing the "normal" stereo file of the song, so when I turn on and off the Dolby Atmos Always On setting there should not be a difference, but there is and it's very noticeable, around 7dB from my super accurate Apple Watch.

Anyone want to verify that I am not crazy?
Song that I notice it the most on is Post Malones WOW

When switching the Dolby Atmos Always On from off to on or on to off I just have to make sure it switches on the phone, sometimes it does it while playing sometimes I need to restart the song until the Dolby Atmos tag either goes away or shows up oil the phone.

 

[lx200inAR]

The Atmos file is a different mix of the same song and if your phone says it's playing the atmos version then it is playing that mix rather than the stereo mix. I suspect all the atmos processing happens before the DAC, so it doesn't really matter what the speakers are. Therefore, it's possible that just on the atmos track the volume or some aspect of the song is exaggerated. This can vary between any atmos vs stereo mix, so it could be a mixed bag.

Apple allows you to use the "Always On" to force the atmos track if you are using a device (android phone or non-apple headphones) that it doesn't recognize that can play the track or not.

 

[TeCKis300]

Our cars are only capable of accepting good ol PCM stereo over Bluetooth. The LX technically has Dolby Surround capabilities, but I don't believe that audio path is possible over BT.

Your phone is downmixing whatever it gets to stereo. What you're hearing is either the downmixer algorithm or like @lx200isAR says, an exaggeration built into the multi-channel mix, that would be better played on a real Atmos decoder and system.

You're going to get the best results on a mix directly compatible with the target audio system. So it plays the way the audio engineer intended. Using more elements in the chain like a surround decoder to feed a stereo encoder is just going to introduce unknowns probably like what you're hearing. Sure, it could lead to some perceived pleasant surprises.

 

[linuxgod]

I guess Atmos must be an iPhone 11 thing. My iPhone X doesn't have that option

 

[lx200inAR]

I guess Atmos must be an iPhone 11 thing. My iPhone X doesn't have that option

Looks like you have to have an XS or newer and IOS 14.6 and newer.

Seems a big chunk of the Atmos technology is tied to the output device rendering the Atmos track into how many ever speakers are available. It is supposed to be able to add more "3d space/effects" to tracks even while rendering in a 2 channel system, which like Teckis stated is all the 200 stereos are going to receive regardless of what multichannel formats the DVD player may be able to decode.

 

[molanginaeda]

I guess Atmos must be an iPhone 11 thing. My iPhone X doesn't have that option

Yup, time to upgrade to newer iphone.

 

[linuxgod]

Yup, time to upgrade to newer iphone.

View attachment 2858062

Heh, this was an upgrade earlier this year from my iPhone 6...

 

[AnyMal]

Atmos is a lossless digital (and backwards compatible) codec that like all of its predecessors carries different subtracks for a variety of mixes but unlike previous dolby digital and dts codecs atmos itself is not channel dependent. Atmos carries metadata for each channel that provides the dynamic "atmospheric" information for that signal even over 2ch despite "real" atmos deployment being designed around 12.6.4 ( i think, er something like that in surround, ceiling and subs).

LXinAR is correct that it is up to the client to decode and output that atmos data in whatever configuration its setup for (even basic stereo subtrack if it receives that)
In this case your iphone is choosing a BT output which (up until very recently) is lossy itself so would be decoding into 2ch LPCM dumping that over BT and your head unit doing the rest yada yada. Could be you never saturated your BT throughput before maybe?

Im not sure what you are saying you are experiencing but in could be possible that track output itself is a better lossless master than the previous and the resulting increase in dynamic range is revealing a more detailed low end even if transmitted over BT (which im not sure which version you have but can make a huge diff itself). I dont believe the iphone downloads multiple copies of a track nor do i know what that file format is if its other than AAC or a new convoluted format of combined formats such as live photos are (they are a .HEIC which is a .mov and .jpeg mashed together apple pie).


What are you saying it sounds like is happening and that you measured 7DB of gain from?