Now That Atmos Is Everywhere… Real vs. Phantom Center in a 5.1 Music-Focused Setup

[krabapple]

For sure, the general state of LP pressings back in the 70s and going forward was mostly horrid. We would spend tons of money buying 2, 3, 4 copies trying to get one with a halfway quiet surface and no other flaws, then searching out imports and later MFSL to find anything just a little bit better..
Today, specially from the guys who specialize in multich mixing like Steven Wilson, Alan Parsons, many more are giving us masters that are made in heaven. Thank God for the music releases of the last decade.

Wilson is giving us *remixes*. (And they ain't all heavenly)

Great mastering comes from elsewhere.

 

[krabapple]

I definately don't want to nourish the believe of people in the false claims of the consumer industry, but - as bad as consumer Atmos is - this is not the case. Apple music delivery specs:

https://help.apple.com/itc/videoaudioassetguide/#/itcf946aaace

In practice music tracks are still produced in stereo and mixed in stereo. Then the Atmos mix is derived from the stereo mix.

That's poor phrasing.

If Apple spec is followed ,

• Dolby Atmos audio files generated from stereo mixes are not allowed. Specifically:
  • A Dolby Atmos track must be created from multitracks or stems created from multitracks.
  • Upmixing from a stereo release is not allowed.
  • Extracting stems (“de-mixing”) from a stereo release is not allowed.
  • A Dolby Atmos track consisting only of a stereo mix placed in the sound field with added ambience or reverb is not allowed.

Such an Atmos mix may be 'derived from' the stereo only in the sense that the stereo mix may serve as a guide for what parts to include and where to place them in the left-right field.

I can't believe this is that complicated.

When the mix is being done, per Soundmixer (supposedly) it's being done in a bass managed environment.

The people doing the mixing aren't hearing those bass notes coming from those surrounds, because the system they are using isn't set up for it.

That doesn't mean that those bass notes don't end up in surround right or left, it just means that was not an intentional move by the person literally making the mix. It again, is a byproduct. Doesn't mean there's no stuff in those speakers, just means that said stuff was always mixed with it coming from the LFE in studio.

Having it be elsewhere is maybe a happy accident, but not intentional production work.

It's not being put there by artists working to get that specific low frequency in that speaker. In the mixing studio it's never actually in that speaker, it is bass managed to the subs/lfe.

If I read you right you're saying that low bass content in surround channels does occur, but it's not meant to be heard from the surround speakers -- it's meant to be rerouted to a subwoofer(s), because, according to you, that's how mix suites are set up to handle it. IOW they do not use (or exploit) 'full-range' surround speakers. (Which may be true for Atmos suites, for all I know, but it was definitely not the industry recommendation for 5.1 mixing -- which was for full range towers all around , plus a subwoofer for LFE; i.e., no bass management; though I expect engineers *should also* have checked for good sound with bass management @ 80Hz in play, just as stereo mixers checked their mixes on crappy speakers to make sure they were still tolerable under less than optimum conditions)

The question would be, why put low bass in the surround then in the first place? You seem to be saying it's an accident. I wonder if it's carelessness? Or making assumptions about consumer setups?

I've seen plenty of strange garbage in the *LFE* channel -- like, full range content -- which leads me to believe those mixers simply assume everyone low-passes their sub content at 80Hz (including the LPF for LFE).


(I'm not sure what any of this has to do with the topic of the thread: center channel use in Atmos).

 

[goat76]

I don't understand the discussion in this thread about the LFE channel in multichannel music mixing. I mean, whatever sounds are routed to the LFE channel is mostly determined by the bass management of the replay system, which is something that comes later rather than something that is done in the mix. The mixing engineers may have full-range speakers all around them, or they may not, but in either case, the systems can be highly optimized, no matter the type of speaker system is used. But in either case, it's not likely that the mix would have been made very differently just because of how the bass management has been done in the studio. It's not like the mixing engineer has set some sort of cut-off frequency in the mix of what goes to the LFE channel when something is panned to the surround channels, well, except if the mix contains some special bass effects, which is probably more common in movies than in music productions.

 

[ace_xp2]

Effectively as you've stated is my perspective krabapple, with the caveat that this:

because, according to you, that's how mix suites are set up to handle it

Is not according to me, as I've said I have no idea how mix suites are set up. But the poster Soundmixer here appears to be a relatively seasoned industry man who does. He and another mixer Audio2920 do mention that bass management is in their spec, naming two major studios (Disney and Sony):

This is why Disney and Sony (and other studios as well) do very specific made for HE mixes. During our first pass, we can listen for discrepancies, and tweak and fix them before encoding. Atmos does not downmix, it adapts to the speaker setup that is configured within the AVR or processor. As far as I know, all Atmos mixes are played back in bass-managed environments, as that is a part of the cinema and home decoding process. It CAN be played back on a non-BM'd system, but the results will not be consistent.

As to the question over why, I don't think that it's carelessness per se. For one, the front speakers set may retain some level of bass so that in the non atmos mix when it's played 2.0 there's still low frequency sounds, which in turn simplifies the creation of that downmix.

Thinking on it too, it might be easier to deal with phase summation by allowing every channel to maintain its below 80hz signal, versus removing it entirely and forcing it to the lfe. While they may not directly test higher crossovers, by working through summation at the 80hz level it may increase the likelyhood that it's still acceptable higher? Only a guess though.

And it doesn't really apply to center channel use in atmos music, the nature of atmos movie mixes came up here just as an aside to this discussion. And I was surprised by the commentary that movie mixes are done that way.

 

[Sal1950]

Wilson is giving us *remixes*. (And they ain't all heavenly)

Great mastering comes from elsewhere.

Call them what you like, I've never heard one that wasn't a big improvement over anything that came before.
There's only so much that can be done with a distorted crap source.

 

[Sal1950]

(I'm not sure what any of this has to do with the topic of the thread: center channel use in Atmos).

Read the thread topic again.

"Now That Atmos Is Everywhere… Real vs. Phantom Center in a 5.1 Music-Focused Setup"

 

[krabapple]

Call them what you like,

Remixing and remastering are very different things. To treat them as the same thing, is just an error.

I've never heard one that wasn't a big improvement over anything that came before.

I sure have. Wilson is highly hit-or-miss. He's way overpraised.

Stephen Taylor, Elliot Scheiner, Greg Penney: these remixers manage to stay more true to the original mix, without losing any of its magic.

There's only so much that can be done with a distorted crap source.

Yet I find, again and again, that I'd rather listen to upmixes of Eddy Offord's 'distorted crap' stereo mixes of Yes and ELP, than what Wilson (and Jakko Jaksyk) has done with the same multis.

 

[krabapple]

Read the thread topic again.

"Now That Atmos Is Everywhere… Real vs. Phantom Center in a 5.1 Music-Focused Setup"

um, yeah, that's my point. The topic reads 'Real vs Phantom CENTER in a 5.1 music-focused setup', but now some are wanging on about surround channels.

 

[Sal1950]

I sure have. Wilson is highly hit-or-miss. He's way overpraised.

BS Your just trying to be negative for political reasons.
Thats your problem

 

[krabapple]

BS Your just trying to be negative for political reasons.

That's an extraordinarily dopey accusation even by ASR standards.

You can look up my negative opinion of SW's work going back years, on QuadraphonicQuad, if you care to.

It's not all about you.

 

[Sal1950]

That's an extraordinarily dopey accusation even by ASR standards.

You can look up my negative opinion of SW's work going back years, on QuadraphonicQuad, if you care to.

It's not all about you.

Uh huh

 

[Fidji]

I don't understand the discussion in this thread about the LFE channel in multichannel music mixing. I mean, whatever sounds are routed to the LFE channel is mostly determined by the bass management of the replay system, which is something that comes later rather than something that is done in the mix. The mixing engineers may have full-range speakers all around them, or they may not, but in either case, the systems can be highly optimized, no matter the type of speaker system is used. But in either case, it's not likely that the mix would have been made very differently just because of how the bass management has been done in the studio. It's not like the mixing engineer has set some sort of cut-off frequency in the mix of what goes to the LFE channel when something is panned to the surround channels, well, except if the mix contains some special bass effects, which is probably more common in movies than in music productions.

You should spend some time understanding differences between LFE channel and bass management. Being uninformed [and wrong] about basics of MCH productions and reproduction makes it very hard to draw correct conclusions.

and FWIW - Atmos and DD/DTS music mixes do use LFE channel quite as standard. There are of course 5.0 mixes especially of classical music, but this is different topic.

 

[goat76]

You should spend some time understanding differences between LFE channel and bass management. Being uninformed [and wrong] about basics of MCH productions and reproduction makes it very hard to draw correct conclusions.

and FWIW - Atmos and DD/DTS music mixes do use LFE channel quite as standard. There are of course 5.0 mixes especially of classical music, but this is different topic.

I do understand the difference between LFE and bass management, but when it comes to music specifically and for most genres, there is not much use for an LFE channel as there is hardly ever any low frequency “effects” going on in music. So most things that will go to the subwoofers in multichannel music will depend on the replay system's bass management settings.

The most common suggestion I see when reading about mixing music in Atmos is not to use the LFE channel, except in rare occasions if the music contains special effects, which in turn is hardly common for most music genres.

If you have found information that the use of the LFE channel in Atmos music mixing is a common thing, I would like to know what the mixing engineers usually use that channel for in music productions.

 

[krabapple]

I do understand the difference between LFE and bass management, but when it comes to music specifically and for most genres, there is not much use for an LFE channel as there is hardly ever any low frequency “effects” going on in music. So most things that will go to the subwoofers in multichannel music will depend on the replay system's bass management settings.

And yet, as has been pointed out to you, the LFE channel really is very frequently populated in surround music releases.

I agree that the vast majority of music doesn't need LFE (which was invented for loud, deep, often transient events in movie soundtracks : arms fire, explosions, earthquakes) ; that its use in music releases is largely pandering to low-info consumers who 1) don't have bass management properly set up and 2) want to hear something thumping from their subs. That means there has to be LFE content.

Sometimes it's very low level; sometimes it is NOT. (and sometimes, yes, it's silent)

So you have to proceed from that basis.

The most common suggestion I see when reading about mixing music in Atmos is not to use the LFE channel, except in rare occasions if the music contains special effects, which in turn is hardly common for most music genres.

Atmos is a chance for the paradigm to change: to use LFE only when it is actually warranted. I don't hold out much hope for that.

If you have found information that the use of the LFE channel in Atmos music mixing is a common thing, I would like to know what the mixing engineers usually use that channel for in music productions.

More information from actual mixers always welcome.

 

[krabapple]

I just checked the 8 channel mixes of the seven Atmos discs I own. (I checked one track on each, using Audacity)

They all have content in their LFE.

Here's the RMS level in dBFS of the front left channel|LFE channel, in each. LFE content consists of 'thumps', unless otherwise noted

Prince Purple Rain -21|-34
Peter Gabriel I/O -22|-38
Yes Close to the Edge -26|-39 (LFE contains full range bass guitar and percussion parts) <--Steven Wilson
Yes Fragile -27|-34 (LFE contains full range bass guitar and percussion parts)<--Steven Wilson
David Bowie Ziggy Stardust -22|-39
Kraftwerk Autobahn -27|-32 (LFE has full range content)
King Crimson Red -24|-39 (LFE contains full range bass guitar part) <-- Steven WIlson

3 out of 7 of these mixes use LFE in a way consistent with its original intent: only reinforcing the loudest, lowest frequency instances in the 'soundtrack' --in music, typically kick drum hits

The others dump full range content of one type or another into it.

 

[Fidji]

I mean, whatever sounds are routed to the LFE channel is mostly determined by the bass management of the replay system, which is something that comes later rather than something that is done in the mix.

Nope. Whatever sounds are routed to the LFE Channel is determined by mix and mix only.

If you have found information that the use of the LFE channel in Atmos music mixing is a common thing, I would like to know what the mixing engineers usually use that channel for in music productions.

As @krabapple has posted I usually observe following [BTW I think you need to add 10dB to your results as LFE will be on 0, and 10dB is added at the output]
1) no LFE used - example Joni Mitchell - Blue, quite common on Atmose mixes of older stuff.
2) “doubling” of base/kick drums - low-pass filtered. If done correctly it result in fuller, punchier sound in bottom octaves.
3) in live or distant mic type of recordings you usually find “venue size” & ambiance in there. People are often surprised how many information is “below the lowest notes”.

Ironically [as to the title of this thread] , you will find lot of mixes that do not use Center channel, but still use LFE.

 

[goat76]

Nope. Whatever sounds are routed to the LFE Channel is determined by mix and mix only.

Sorry, I actually miswrote that.

What I meant to say was that most low-frequency sounds that go to the subwoofers (mistakenly wrote LFE) in Atmos music is mostly determined by the sound system’s bass management, as there is usually very little to route to the LFE channel in most type of music.

As @krabapple has posted I usually observe following [BTW I think you need to add 10dB to your results as LFE will be on 0, and 10dB is added at the output]
1) no LFE used - example Joni Mitchell - Blue, quite common on Atmose mixes of older stuff.
2) “doubling” of base/kick drums - low-pass filtered. If done correctly it result in fuller, punchier sound in bottom octaves.
3) in live or distant mic type of recordings you usually find “venue size” & ambiance in there. People are often surprised how many information is “below the lowest notes”.

Ironically [as to the title of this thread] , you will find lot of mixes that do not use Center channel, but still use LFE.

I only had time to listen to one of the examples @krabapple gave, the Close to the Edge track I found on Tidal in Dolby Atmos. I turned off the amp that drives the front speakers and set all the speakers to large in my reciever, and while I could hear something coming from the subwoofers when listening close up, it wasn't much.

I will analyze more tracks when I have time, but the common suggestion I read is not to use the LFE channel for much more than enhancements and special effects, which most type of music mixes will probably not need.

 

[krabapple]

Nope. Whatever sounds are routed to the LFE Channel is determined by mix and mix only.



As @krabapple has posted I usually observe following [BTW I think you need to add 10dB to your results as LFE will be on 0, and 10dB is added at the output]
1) no LFE used - example Joni Mitchell - Blue, quite common on Atmose mixes of older stuff.

I'm thinking it's relatively rare, myself.

2) “doubling” of base/kick drums - low-pass filtered. If done correctly it result in fuller, punchier sound in bottom octaves.

But it seems some mixers rely on the playback system to do the low-pass filtering 'correctly'. (How do we know what 'correctly' meant to them?)

 

[Fidji]

I think there are 2 type of Atmos mixes - there are high quality remixes to Atmos - done by the likes of S. Wilison, D. Kosten etc - where you ger re-interpretation of the underlying record, Actually I can not remember hearing bad S Wilson Atmos mix, from technical point of view. But it must be expensive and you often see thos released on BR Audio.

Then there is Spatial Audio/Atmos mixes published in hundreds, for Apple Music/Tidal, where I have the suspicion, that they are done by some interns or AI. They bring nothing from artistic point of view only they are usually not so brutally compressed and have DR around 11-14, instead of usual 5-6 of 2CG digital release.

 

[Sal1950]

I think there are 2 type of Atmos mixes - there are high quality remixes to Atmos - done by the likes of S. Wilison, D. Kosten etc - where you ger re-interpretation of the underlying record, Actually I can not remember hearing bad S Wilson Atmos mix, from technical point of view. But it must be expensive and you often see thos released on BR Audio.

BR media is mostly needed for the room to not only use high data rate, uncompressed, data of the basic album but to also include additional material whether more music/songs, some video, whatever. DVD and SACD media has also been used to offer needed data elbow room but time marches on.

Then there is Spatial Audio/Atmos mixes published in hundreds, for Apple Music/Tidal, where I have the suspicion, that they are done by some interns or AI. They bring nothing from artistic point of view only they are usually not so brutally compressed and have DR around 11-14, instead of usual 5-6 of 2CG digital release.

A lot of truth there, many artists, engineers, labels have rushed to take advantage of the popularity of immersive music but still the statement is only supported on a recording to recording basis. Steven Wilsons incredible talent in both original mastering and the remixing of older material is also what being used to populate the streaming catalogs. Unfortunately at present, lossy compression is being used to stream the large amount of data contained in lossless versions. All for the same reasons that lossy file codec were used for 2ch streaming that went on for decades. Hopefully as all the technology involved improves the call for lossless multich streaming will be heard and have it's effect.
Shoot, Spotify still hasn't totally switched after how many years of unmet promises