TrueImage vs Direct for Atmos on either ATV device or the Apple App

[SimonWeir]

Which is better in your opinion?

Using an ATV device into the Theatre with the Atmos codec showing as PCM vs Apple App on LG G3 OLED using pass through to the Theatre where the Atmos codec is now showing as DD+ for the same film?

My channel output allocation is 7.1.4 because I have a Theatre and also physical speakers (3 sets of BL17 and a BL19) I use the Theatre FL, FR, FC  for the centre and the Theatre Up firing for Left & Right Front Height and the Theatre Surround for Left & Right Surround Height so with my BL17s assigned for FL, FR, SL, SR, BL, BR, and my BL19 assigned as subwoofer I get 7.1.4.

When watching a film using the latest Apple 4K TV 2022 device I get a Dolby Vision message on the screen and I see from the signal information in the B&O App is PCM a lossless codec and channel allocation is Atmos.   The problem I think is this strips the Atmos metadata so the height channels are removed because PCM can only support up to 7.1.  Which is why I have my Theatre’s Movie sound mode set to TrueImage so sound comes out of the 4 height assigned speakers but I think this sound is not actually height information, but a mix of surround and back sound.

When I watch the same film on the Apple TV App on my LG OLED G3 2023 that can pass through to the Theatre on the screen I get a message saying Dolby Vision & Atmos via sound bar.  In the B&O App it shows the signal information is Atmos via Dobly Digital Plus codec.  I think this has kept the metadata and so has separate height channels but DD+ is a lossy codec.  When I change between TrueImage and Direct I do not hear a difference.

It seems strange to me that a physical device using hdmi 2.1 and all the processing power of the ATV might be sounding less as intended by the film sound engineer than via a smart TV app with less sound processing power because it cannot handshake with the Theatre in direct.

I do not always trust my ears so I have ordered Spatial Audio Calibration Toolkit (Blu-ray Atmos Disc) to play Atmos test tones in Dolby TrueHD from my Panasonic UB820 into the Theatre for each speaker to prove to me that each specific channel is going to the correctly assigned speaker.  An expensive purchase £115 for a Blu-ray Disc that I may only use once but at least I can then send feedback back to Bang Olufsen.

All thoughts and suggestions welcomed.

Thanks Simon.

 

[SimonWeir]

Follow up… a response to my similar post from the Apple Community

“The Apple TV 4K box will output Dolby Atmos in Dolby MAT format, uncompressed like PCM, with a sub-stream that represents the object based mix, to audio devices that support this. Content from commercial online streaming provider apps do not get stripped of Atmos meta data. In fact, it is very similar to Dolby Digital Plus with Atmos, as that is how it streams to the device.”

“content on the Apple TV app on is equal quality to the Apple TV 4K box, unless your audio system supports Dolby Digital Plus with Atmos, but not Dolby MAT (rare these days).”

From the spec sheet on the B&O website I see the Theatre supports Dolby MAT, so why if the above is the case does the B&O App not show Dolby Atmos via Dolby MAT and instead shows Dolby Atmos via PCM?

Hoping Geoff Martin may comment because I think I am left with an answer that the sound direct into the Theatre from a latest Apple TV box should be in Dolby MAT and be better than via the App into the Theatre but then why does TrueImage sound different as all settings are at their factory defaults and I have the correct number of speakers, so in practice should be behaving as Direct.

When the text tone disc arrives I will post my findings.

This is a real nerdy issue as the sound is incredible… I just need peace of mind to know everything is working as intended, and go back to enjoying films instead of walking round with my ear to each speaker and my wife thinking I am going insane! ?

[Mark]

SimonWeir wrote:

why does TrueImage sound different as all settings are at their factory defaults and I have the correct number of speakers, so in practice should be behaving as Direct.

Just out of curiosity, how does each of those settings sound?  I know everyone has different preferences, but does direct sound [much] better than TrueImage, or are they both listenable?

 

[SimonWeir]

Mark, both sound great.  Remember B&O owners expectations are ridiculously high… but we are financially and time heavily invested so our systems should sound great and when you hear other systems you should be able in my opinion to hear the difference between B&O and other manufacturers.

Back to back between the two sound processing, I get the personal sense that TrueImage has slightly more envelopment than Direct and it is more forgiving on seating sweet spot as some channels seem to be blended across multiple speakers, nothing overtly obvious and TrueImage is my default for all viewing both Film & Music except for UHD Blu-Ray because I know all the channel information is coming through uncompressed.

The clear sound difference in using Direct is actually the silence from speakers when not receiving a source which is odd for normal viewing, but to me is the most accurate reproduction of the source, hence why I use for Blu-Ray and hope to do for all Atmos input when I can confirm that tones are correctly being sent to the correct assigned speakers.

I have offered John (previously Manchester B&O) and Ian (Manager of B&O Manchester) plus B&O UK leadership / technical to come and film at my house because it is only in actual homes with unique layout limitations will the developers / sound engineers get feedback other than in their controlled conditions / their own home testing of room compensation and what is typical usage, e.g. I bet no one opens and closes as frequently throughout the day and has the TV open at 60 degrees on the automated wall bracket for hours each evening as I do, and have needed to have the TV re-levelled as often as I have, because the weight on the bracket + TV + Theatre over time affect the 13 bolts anchoring the Theatre so the whole setup starts to sag on the corner not anchored to the wall by at least 2cm which is very noticeable when watching programmes that the screen in not level.  Plus I get the sense owners are quicker to identify bugs but we struggle to convey to Head Office via the small message box what we hear / are experiencing.

[Mark]

Thanks Simon,

I don’t mean to distract from your question, but TrueImage vs Direct in general has been an interest of mine.  I have a 5.1 setup with my Theatre, with 18’s up front and 17’s in the rear on bookcases.  I think the 17’s are a little too high for me to really hear their presence.  I can’t give any opinion on Dolby Atmos.

A while ago I watched Andrew Robinson’s review on the Beosound Theatre.  For him the direct mode for listening to music was better than TrueImage because it fixed a dip in the frequence response, if I recall correctly.  I tried Direct vs TrueImage on my system for music and I preferred the TrueImage.  That made me wonder if I should have preferred the probably more-processed TrueImage over the purer Direct.  For me and my environment the Engineers at B&O provided an improvement with TrueImage.  I really can’t compare my system to someone elses system.

[Sandyb]

I understand the “issue”, and picked a Netflix atmos movie (6 Underground) on both the WebOS NTFLX app and on the ATV NTFLX app.

I cant really tell any difference between the sound image produced, specifically when it comes to height effects (I dont have physical height speakers, only 50s up front and 17s behind me).

From what I understand (from the FlatPanels Theatre review), B&O have somewhat turned down the height/Atmos effects on the Theatre (they mentioned something about it being fatiguing in their opinion if jacked up fully).

I say this simply because, specifically absent physical height / ceiling speakers), and with the height image tuned down by the Theatre (by their design / admission), its not surprising we hear no difference (image height wise) between the Atmos / PCM and Atmos / DD+ signals.

So in the end, its not something I get over-exercised with.

If I really want a generally superior audio soundtrack, I just use a UHD BluRay.  I just got Dune (2021) on UHD disc, and it sounds pretty fantastic, although of course thats full everything – Atmos / Dolby True HD, and the height effects are at times quite noticeable, and certainly better than either of the 6 Undergound Netflix paths I tried above.

[SimonWeir]

Thanks for trying it out for yourself Sandyb, it is appreciated and I am glad you are getting a similar result.  Like you I now revert to buying a UHD disc for the full experience, and because I have the required number of speakers set to Direct.

The Theatre has moved me back to buying UHD discs and I use streaming less.

I must have missed in all the reviews of the Theatre that B&O may have dialled back the height channels.  The Up Firing and Side Firing speakers are very capable so I have edited the Movie sound mode from:

Surround = 5, Height = 5, Stage Width = 5, Envelopment = 5

to:

Surround = 6, Height = 7, Stage Width = 5, Envelopment = 5

For Netflix and Prime and via ATV using Atmos PCM or the LG Apps using Atmos DD+ I now hear closer to the Direct sound mode balance of height sounds when playing a UHD disc with Atmos TrueHD.

No fatigue rather better experience, especially in the Topgun Maverick ‘2:15 training run’ scene and Bond No Time To Die ‘church bells shoot out’ scene.

The sound mode section on the app is something I had not used much off, but very interesting to see the different settings between TV, Music, Movie etc and I now have been able to tailor to what I want to hear emphasised.

[Sandyb]

Yeah, it was only in the FlatPanels review that something was mentioned.

Anyway, I’m not too stressed about it tbh, as most of my movie preferences are not action type stuff, so Atmos is less of an issue (I used 6 Underground this morning just as a test, not a film I’d watch myself)

But having put in the UHD Dune disc this morning (Dolby True HD as the Atmos container) early on in the film there was some rain effects that were clearly noticeable as a pretty good height effect.

When I watched Dune for the first time last week on Sky (DD+ Atmos), that rain from above effect was weaker.

And thats before we get to the vocal mixing – on the broadcast DD+ Dune, usual problem of vocals back in the mix, hard to hear at sensible volumes, and the usual dance of volume up, and then back down,  The UHD disc was perfect – could listen at volume 43-44 with perfect mix and clarity, whereas in the broadcast DD+ mix, at times volume was up to 55-56 to hear the vocals inteligegably.

Discs rule (at least for a movie worth buying)

 

[Millemissen]

Geoff Martin said this

MM

[Sandyb]

interesting of course, but not sure if it addresses the original question though.

[Millemissen]

Sandyb wrote:

interesting of course, but not sure if it addresses the original question though.

—————

No, not directly – but it explains how the True Image processing compared to the Direct Mode works.

Basicly the True Image leaves the incoming signal untouched, if the speaker layout matches the incoming signal (as it always has done).

This means, that – if you use Direct Mode and there are more ‘channels’ coming in than your speaker setup provides – you might loose some information.

—

As for comparing sound from the ATV device with that of the ATV app/LG tv….I find it hard to do such ‘A/B testing’ – there are too many variables in the game. Since I never use the apps on the LG, I can hardly comment on the original question of the thread.

MM

[NQVHNWI]

My opinion (with 2 pairs of heights) in a 5.0.4 configuration is that the Theatre is infinitely adjustable in terms of atmospheric sound distribution. I use the RoomSense to get me 90% ball-park of what I need.

I convert the BSTheatre speakers to front only, with the side and up firing off.
I push the fronts slightly backward in terms of distance, but pull the sound level higher for clearer vocals.

The BL90s require a slight distance adjustment either side and the BL3 Surrounds left alone. The heights are manually boosted a fraction of a db each on the rear heights, a bit more on the front heights. I tend to lave the sound modes alone after getting hopelessly lost in the Miriam of settings. Writing down default distances and sound levels and their modified settings is useful.

This gets me to my desired preference and how far away it is from yours and the degree of tinkering/tuning is entirely personal. I don’t see the need to move away from TrueImage – though direct May have been useful while B&O were fixing the BSTH bugs.

As indicated, a good 4KBR disc – or like me enjoying completely uncompressed audio makes a huge difference over Netflix or Amazon (which although it says Dolby Atmos, is still no bigger than DD+) in terms of spacial atmosphere.

On my Kaleidescape system, I have a freebie short movie by Trinnov – perhaps the leader in home theatre amplification and distribution. It’s a musical track of beating and twanging noises coming from what seems a collection of hotch-pitch electrical components (I can’t find a link on their site). But it gives a very good 3D spacial observation of the sound and to a degree, helps me tune the heights to a degree where there is clear separation but not stupidly unrealistic separation.

In summary, find a good Atmos source, tweak to your hearts desire and how other people do it or take as preference I think is relatively meaningless to your own setup.

[Sandyb]

agree, the A/B testing between streaming versions I did this morning is not an exercise I’d repeat, its a bit tedious and I’m not technical enough to understand exactly what the ATV does with Atmos streams from various apps before outputting it as PCM (the ATV doesn’t do passthrough).

But the A/B I did between the ATV Netflix and the webOS Netflix revealed nothing material difference wise.

UHD Discs on the other hand show some more obvious sound quality improvements.

Thats the extent of my wisdom!

[Author]

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