[Dolby Atmos] Do I have to have a bed?

[Bearcat_Sandor]

I'm an audio engineering student, and I'm going to be working with Dolby Atmos. If I know that I'm not going to need to deliver a file for a decreet channel set-up, can I create an Atmos mix that only contains objects with no bed?

 

[timothyemerson]

I'm an audio engineering student, and I'm going to be working with Dolby Atmos. If I know that I'm not going to need to deliver a file for a decreet channel set-up, can I create an Atmos mix that only contains objects with no bed?

From the title of the post, I thought someone was considering selling their bed so they could afford an Atmos setup.

... and now, we wait for someone with an Atmos setup to chime in with a proper answer...

 

[sjcorne]

If you want to send audio to the LFE channel, I'm pretty sure you have to use the bed.

 

[Bearcat_Sandor]

From the title of the post, I thought someone was considering selling their bed so they could afford an Atmos setup.

... and now, we wait for someone with an Atmos setup to chime in with a proper answer...

That's not an unreasonable scenario.

 

[Bearcat_Sandor]

If you want to send audio to the LFE channel, I'm pretty sure you have to use the bed.

Ah yes, I'd forgotten about the LFE. So, you could have 1 bed channel for the LFE, and the rest of your channels (minus the time code channels) could be object channels?

 

[AudiophileStyle]

Ah yes, I'd forgotten about the LFE. So, you could have 1 bed channel for the LFE, and the rest of your channels (minus the time code channels) could be object channels?

Yes.

 

[Bearcat_Sandor]

So, if you don't need an LFE because you're mixing for music, you can use none? Cool.

 

[DuncanS]

If there isn't a Bed will AVRs still decode the ATMOS correctly? As I thought ATMOS removes the objects from the bed and positions them according to the mixes object positioning & the AVR speaker set-up.

 

[AYanguas]

If there isn't a Bed will AVRs still decode the ATMOS correctly? As I thought ATMOS removes the objects from the bed and positions them according to the mixes object positioning & the AVR speaker set-up.

I think AVRs should decode right, assuming there is no bug on its firmware.

Could it be that with few speakers the rendering is 'less' precise than directing the content to the bed channels? I really don't know, but I guess it should not be.

Some of us always pray for good Atmos mixes that explore the whole 3D space and make use of the Wides (for instance). So mixing mainly or exclusive using Objects with different locations and settings, IMO, should be the best creative way of doing it.

In any case, the Mixer should 'test' what he has mixed, in much as scenarios as possible (5.1, 7.1.4, more speakers if available, Headphones Dolby, Headphones Apple,...) if avaialble in his mixing studio.

 

[austinsignal]

If there isn't a Bed will AVRs still decode the ATMOS correctly? As I thought ATMOS removes the objects from the bed and positions them according to the mixes object positioning & the AVR speaker set-up.

There are definitely people out there that put everything into objects, and don't use the bed at all. There are also those that only use the bed, with no objects. There are advantages and disadvantages to both methods. The most popular approach is to use both...

 

[ar surround]

There are definitely people out there that put everything into objects, and don't use the bed at all. There are also those that only use the bed, with no objects. There are advantages and disadvantages to both methods. The most popular approach is to use both...

So does the term 'bed' mean material that is distinctly placed in each speaker (or number of speakers) whether it be floor or ceiling speakers?

For example, an Atmos test disc that places a test tone discretely in each speaker...does that employ the 'bed?'

(@barfle may be interested in this discussion also.)

 

[austinsignal]

So does the term 'bed' mean material that is distinctly placed in each speaker (or number of speakers) whether it be floor or ceiling speakers?

For example, an Atmos test disc that places a test tone discretely in each speaker...does that employ the 'bed?'

(@barfle may be interested in this discussion also.)

no - you can pan audio in the bed all around, up and down in the bed....

 

[AYanguas]

The Atmos bed Channels, AFAIK, are the direct speaker assignments for 7.1.2

I.e. the 7.1 floor, LFE, and only two 'stereo' Tops.

If something is desired to the Wides, or to differentiate the Tops front, middle, rear, then Objects are needed.

 

[austinsignal]

The Atmos bed Channels, AFAIK, are the direct speaker assignments for 7.1.2

I.e. the 7.1 floor, LFE, and only two 'stereo' Tops.

If something is desired to the Wides, or to differentiate the Tops front, middle, rear, then Objects are needed.

True for the height speakers for sure. If you're panning content up high in the bed, it's going to all 4 speakers, with no control over front/back, left/right. Not so sure about the wides though. I'm not running a 9.1.4 rig, so I can't test it. I'm certain that if I'm panning content around the bed, it would certainly take advantage of the wides when doing so....

 

[AYanguas]

True for the height speakers for sure. If you're panning content up high in the bed, it's going to all 4 speakers, with no control over front/back, left/right. Not so sure about the wides though. I'm not running a 9.1.4 rig, so I can't test it. I'm certain that if I'm panning content around the bed, it would certainly take advantage of the wides when doing so....

I remember that @sjcorne confirmed object location at 65º (or so) renders output exactly only at the Wide.

I have no idea if when the mixing tools pan sound over the bed channels it will be rendered also on non bed channels (Wides). I didn't play with any mixing tool.
But I wil be glad to test in my 9.1.4 if some files are provided

 

[AYanguas]

I remember that @sjcorne confirmed object location at 65º (or so) renders output exactly only at the Wide.

I have no idea if when the mixing tools pan sound over the bed channels it will be rendered also on non bed channels (Wides). I didn't play with any mixing tool.
But I wil be glad to test in my 9.1.4 if some files are provided

Or another way to test (without the proper rig) would be to decode the Atmos file to mch WAV 9.1.6, using MMH, and then inspect the WAV file with Audacity.

 

[jimfisheye]

I'm an audio engineering student, and I'm going to be working with Dolby Atmos. If I know that I'm not going to need to deliver a file for a decreet channel set-up, can I create an Atmos mix that only contains objects with no bed?

You can experiment and find out.

You can always deliver a bed to the renderer that is digital silence and just put audio to objects. The software will be happy and then you'll be happy.

And of course your mix can always be delivered sans any Dolby encoding as you please. Wavpack works for 12 channel files, for example. But I'd spoof the renderer with blank silent bed audio if it pushed me to use a bed track no matter what.

 

[barfle]

So does the term 'bed' mean material that is distinctly placed in each speaker (or number of speakers) whether it be floor or ceiling speakers?

For example, an Atmos test disc that places a test tone discretely in each speaker...does that employ the 'bed?'

(@barfle may be interested in this discussion also.)

In reading the thread, I've always figured the "bed" meant the channels of (up to) 7.x. And, I always figured that the Atmos metadata would subtract a signal from the bed and place it in space with volume and phase of all speakers available to it.

I'd really like to see some technical specs, so I don't have to guess and assume. I'm surprised nobody here has access to any AES journal entries, at least.

 

[sjcorne]

I'm certain that if I'm panning content around the bed, it would certainly take advantage of the wides when doing so....

I have no idea if when the mixing tools pan sound over the bed channels it will be rendered also on non bed channels (Wides).

Only objects will engage the wides. If you were to pan something in a circular pattern within the bed, the sound would travel from the sides to the fronts and ignore the wides.

A good example of this is in “Won’t Get Fooled Again” from Who’s Next - the synthesizer intermittently moves around all seven floor channels, but the wides only feature some dry lead vocal.

In Pro-Tools, if I set my object panner’s F/R dial to 68% (with no height) the sound comes exclusively from the wide speakers.

https://immersiveaudioalbum.com/dolby-atmos-faq-background-setup-mixing-tips/

 

[HomerJAU]

If I remember correctly when I was mixing Atmos in Cubase I could set the location of all tracks. Which means I could define the floor 7.1 to any position in 3D space.

I never changed the default positions for channels 1 to 8 though. But it may be worth testing.