The state of Object Based Audio, what does the future hold?

[yepimonfire]

This post can also be found on my blog in my signature.

More and more movies are being released in Atmos or DTS: X. Atmos seems to be king in this area, surprisingly. I’m not sure if it’s due to DTS releasing X so much later than Atmos or some other reason. Honestly I figured DTS: X would eventually come out on top, because for one, it’s costs nothing to implement to studios who already have DTS MA, and two, it appears much easier to work with from a mixing perspective, it also doesn’t require expensive certification by DTS before being allowed to be implemented in cinemas or studios.

Atmos mix studios and theaters must meet strict requirements (similar to the old Dolby Digital requirements for dub stages). With DCI, multichannel audio is now packaged as straight 24/48 LPCM, and while Dolby certification is required for dub stages who intend to mix DVD, Bluray, or streaming in a Dolby audio format, as far as I know, no such requirements exist from DTS. A re-recording engineer (the guy who does the nearfield mix for bluray from the theatrical stems) can simply encode the final mix into DTS HD-MA.

Streaming WILL eventually replace physical discs, much in the same way digital downloads and streaming has done for music. VUDU now offers atmos with their UHD releases in Dolby Digital plus, at a bitrate high enough that I can’t hear a difference from the lossless track. Netflix has also dipped its toes into atmos, staring with Xbox one s/x and their original, Okja. If the US can ever get out of the dark ages and switch to a fiber optic network, both on the transmission end and receiving end (crossing my fingers that google fiber gives this the push it needs), there is no reason why gigabit internet speeds won’t eventually become commonplace, enabling the 50-100mbps transfer rate required of UHD Bluray quality HEVC with lossless audio over the internet.

Microsoft Xbox and Windows both natively support atmos, in fact anybody with a windows pc hooked into an atmos capable avr can select atmos as a “channel configuration” from the sounds and devices setting in the control panel, and all content from stereo to actual atmos will be sent as objects. Several games on PC and Xbox also natively support atmos, Overwatch and Battlefield 1 bring two of them. The list is likely to grow.

The new ATSC 3.0 standard for UHD broadcast has (or most likely will) utilize Dolby AC4, which supports up to 7.1.4 channel based audio and object based audio, and all AC4 chips in set top boxes and TVs are capable of transcoding AC4 into TrueHD with atmos metadata for perfect backward compatibility.

While proper Object Based home theater installations utilizing 7 or more channels with actual overhead speakers are only common place in the homes of people like the ones found on these forums, technology still exists to allow those without the space or desire to implement a proper in/on ceiling setup to enjoy object based audio via ceiling bounce speakers, and now the new DTS: Virtual X technology. While most of us agree that real ceiling speakers are the best route, atmos enabled speakers, especially better designed ones such as the Klipsch RP-140sa (which had excellent directivity control for obvious reasons) still make an improvement in the immersion of the sound stage. Many HTiB system now feature atmos enabled speakers, and several sound bars have been released with the technology, making it more likely you average consumer will bite into object based audio.

When discrete 5.1 audio was released to the public via Dolby Digital and later DTS, it was only a matter of time before cable and satellite services, terrestrial broadcast, and Netflix’ rather novel streaming service adopted Dolby Digital 5.1 as the “standard” format.

Object based audio is the biggest improvement to multichannel audio since discrete 5.1, and those who have experienced a proper setup will agree that Atmos certainly imparts the same major leap in benefit as 5.1 did. The real question, considering the above, will Object Based Audio follow the same path and become the major encoding and delivery format, replacing 5.1/7.1 channel based audio as we know it?

I’d be interested in hearing thoughts and opinions!

 

[Blue Dude]

It is likely that object based audio layouts will be fully implemented in only a small minority of homes. Most folks do well if they have a properly installed and dialed in 5.1 system. One very smart thing Dolby and DTS did with both Atmos and DTS-X is that they are both layout agnostic. They are implemented on top of the base 7.1 layer so there's no need to "replace" 5.1/7.1 channel based audio. I'm grateful for the opportunity to experience object based audio, and I seek out discs that have it, but the same disc and same audio track plays perfectly well on 5.1 setups too. The same is true for streaming services. Most users won't know or care about the Atmos metadata and will simply play the base 5.1 Dolby Digital Plus track and be content. The extra data doesn't take much bandwidth and fiber optic speeds aren't required for a DD+ Atmos overlay, so hopefully the streaming services will get on board sooner rather than later and offer Atmos when the mix is available.

 

[Auditor55]

This post can also be found on my blog in my signature.

More and more movies are being released in Atmos or DTS: X. Atmos seems to be king in this area, surprisingly. I’m not sure if it’s due to DTS releasing X so much later than Atmos or some other reason. Honestly I figured DTS: X would eventually come out on top, because for one, it’s costs nothing to implement to studios who already have DTS MA, and two, it appears much easier to work with from a mixing perspective, it also doesn’t require expensive certification by DTS before being allowed to be implemented in cinemas or studios.

Atmos mix studios and theaters must meet strict requirements (similar to the old Dolby Digital requirements for dub stages). With DCI, multichannel audio is now packaged as straight 24/48 LPCM, and while Dolby certification is required for dub stages who intend to mix DVD, Bluray, or streaming in a Dolby audio format, as far as I know, no such requirements exist from DTS. A re-recording engineer (the guy who does the nearfield mix for bluray from the theatrical stems) can simply encode the final mix into DTS HD-MA.

Streaming WILL eventually replace physical discs, much in the same way digital downloads and streaming has done for music. VUDU now offers atmos with their UHD releases in Dolby Digital plus, at a bitrate high enough that I can’t hear a difference from the lossless track. Netflix has also dipped its toes into atmos, staring with Xbox one s/x and their original, Okja. If the US can ever get out of the dark ages and switch to a fiber optic network, both on the transmission end and receiving end (crossing my fingers that google fiber gives this the push it needs), there is no reason why gigabit internet speeds won’t eventually become commonplace, enabling the 50-100mbps transfer rate required of UHD Bluray quality HEVC with lossless audio over the internet.

Microsoft Xbox and Windows both natively support atmos, in fact anybody with a windows pc hooked into an atmos capable avr can select atmos as a “channel configuration” from the sounds and devices setting in the control panel, and all content from stereo to actual atmos will be sent as objects. Several games on PC and Xbox also natively support atmos, Overwatch and Battlefield 1 bring two of them. The list is likely to grow.

The new ATSC 3.0 standard for UHD broadcast has (or most likely will) utilize Dolby AC4, which supports up to 7.1.4 channel based audio and object based audio, and all AC4 chips in set top boxes and TVs are capable of transcoding AC4 into TrueHD with atmos metadata for perfect backward compatibility.

While proper Object Based home theater installations utilizing 7 or more channels with actual overhead speakers are only common place in the homes of people like the ones found on these forums, technology still exists to allow those without the space or desire to implement a proper in/on ceiling setup to enjoy object based audio via ceiling bounce speakers, and now the new DTS: Virtual X technology. While most of us agree that real ceiling speakers are the best route, atmos enabled speakers, especially better designed ones such as the Klipsch RP-140sa (which had excellent directivity control for obvious reasons) still make an improvement in the immersion of the sound stage. Many HTiB system now feature atmos enabled speakers, and several sound bars have been released with the technology, making it more likely you average consumer will bite into object based audio.

When discrete 5.1 audio was released to the public via Dolby Digital and later DTS, it was only a matter of time before cable and satellite services, terrestrial broadcast, and Netflix’ rather novel streaming service adopted Dolby Digital 5.1 as the “standard” format.

Object based audio is the biggest improvement to multichannel audio since discrete 5.1, and those who have experienced a proper setup will agree that Atmos certainly imparts the same major leap in benefit as 5.1 did. The real question, considering the above, will Object Based Audio follow the same path and become the major encoding and delivery format, replacing 5.1/7.1 channel based audio as we know it?

I’d be interested in hearing thoughts and opinions!

I don't agree that object based audio is same step forward as discrete 5.1. In my opinion object based audio is more evolutionary than revolutionary like 5.1 discrete audio was. Simply because we went from analog to digital, which was revolutionary, at the cinema and in our homes. The first discrete 5.1 movie I saw at the movies was Golden Eye in Dts and I was simply blown away. Didn't even know what dts was at that time because it was about Dolby sound. The first Dolby Atmos movie I saw was Stephen King's IT, it was impressive, however not a game changer like going from Dolby stereo analog to discrete 5.1 digital.

 

[shadyJ]

To be honest, I don't think the Klipsch RP-140sa looks like a very good design for an Atmos module or whatever you want to call them. I don't know that a small speaker could, since they tend to have wider dispersion patterns at higher frequencies. I don't think that wave-guide would help a whole lot.

By the way, gaming has been doing object-oriented surround sound mixes for a looong time now, ever since the late 90s at least. Film is about 20 years behind the times.

 

[Auditor55]

Also, for streaming services to only offer Atmos on UHD titles is a death nail. Quite honestly, I'm years away from upgrading to an UHD set. Some studios are doing the same with disc, only offering Atmos on UHD titles, again I'm not ready to upgrade my TV nor blu ray player to UHD.

 

[yepimonfire]

To be honest, I don't think the Klipsch RP-140sa looks like a very good design for an Atmos module or whatever you want to call them. I don't know that a small speaker could, since they tend to have wider dispersion patterns at higher frequencies. I don't think that wave-guide would help a whole lot.

By the way, gaming has been doing object-oriented surround sound mixes for a looong time now, ever since the late 90s at least. Film is about 20 years behind the times.

From a technical perspective, I see your point. As far as localization is concerned, frequencies above 1khz are very important. The xover point chosen is odd, considering nearly every 4” driver Klipsch has put into their speakers has been crossed over a bit higher. The Klipsch R-14m has an xover point of 2250hz, and has pretty well controlled directivity from about 1.3khz on up. RB-10 crossed over at 2800hz, and displays similar directivity. I don’t own the 140sa, so I haven’t been able to measure them. Being that the horn is 90x90, if the module is around 90 degrees off axis, wherever directivity control begins, the spl should be about 12dB down.

Many of the reviews have been quite positive on it. https://www.soundandvision.com/content/klipsch-reference-premiere-rp-140sa-atmos-elevation-module-review

https://hdgear.highdefdigest.com/27568/klipschreferencepremiereserieswithdolbyatmos.html

Perhaps I can convince Klipsch to let me borrow a pair for review.

 

[yepimonfire]

Also, for streaming services to only offer Atmos on UHD titles is a death nail. Quite honestly, I'm years away from upgrading to an UHD set. Some studios are doing the same with disc, only offering Atmos on UHD titles, again I'm not ready to upgrade my TV nor blu ray player to UHD.

Agreed, but we’re also seeing the same problem with UHD Blu-ray. Luckily, a UHD bdp should be able to downscale to 1080p. VUDU has also made a good effort to significantly reduce their uhd content, often beating the bluray.

 

[yepimonfire]

To be honest, I don't think the Klipsch RP-140sa looks like a very good design for an Atmos module or whatever you want to call them. I don't know that a small speaker could, since they tend to have wider dispersion patterns at higher frequencies. I don't think that wave-guide would help a whole lot.

By the way, gaming has been doing object-oriented surround sound mixes for a looong time now, ever since the late 90s at least. Film is about 20 years behind the times.

True. Multichannel audio in games is rendered on the spot to fit the current speakers arrangement. Since atmos is obviously proprietary, we have no idea what differences might be. Processing power needed is definitely greater though, especially when the channel count increases. It’s easy to attach a sound to an object in a video game and give it x/y coordinates in the sound engine, it’s a whole different game when you start rendering it in three dimensional space. It’s like going from 2D gaming to 3D. Any piece of crap laptop can run simple two dimensional games, but try to play something like The Witcher 3 on it, and you’d need significantly more powerful hardware.

 

[shadyJ]

True. Multichannel audio in games is rendered on the spot to fit the current speakers arrangement. Since atmos is obviously proprietary, we have no idea what differences might be. Processing power needed is definitely greater though, especially when the channel count increases. It’s easy to attach a sound to an object in a video game and give it x/y coordinates in the sound engine, it’s a whole different game when you start rendering it in three dimensional space. It’s like going from 2D gaming to 3D. Any piece of crap laptop can run simple two dimensional games, but try to play something like The Witcher 3 on it, and you’d need significantly more powerful hardware.

What Atmos is doing is not much different. 3D games have been using XYZ coordinates for many years now, and rendering that on your sound system, up to 7 channels. I don't think the addition of a few more channels isn't going to greatly increase the processing power needs. Atmos also assumes fixed speaker positions. The speakers are merely output objects. From a gaming perspective, what Atmos doing isn't that complicated. In fact, I am betting it is relatively simple, since Atmos doesn't have to consider things like altering the sounds based on the acoustic environment of the virtual space being reproduced. I don't believe it is adding reverb or doppler effects or things like that. Games do. My understanding is that Atmos merely positions prerecorded sounds in a 3D space.

 

[yepimonfire]

What Atmos is doing is not much different. 3D games have been using XYZ coordinates for many years now, and rendering that on your sound system, up to 7 channels. I don't think the addition of a few more channels isn't going to greatly increase the processing power needs. Atmos also assumes fixed speaker positions. The speakers are merely output objects. From a gaming perspective, what Atmos doing isn't that complicated. In fact, I am betting it is relatively simple, since Atmos doesn't have to consider things like altering the sounds based on the acoustic environment of the virtual space being reproduced. I don't believe it is adding reverb or doppler effects or things like that. Games do. My understanding is that Atmos merely positions prerecorded sounds in a 3D space.

I’m actually hoping that Atmos eventually gets an “upgrade” that does render a virtual acoustic space, with reflections and Doppler effects, etc.

We must be getting the shaft from avr manufacturers if their DSP chips are so weak that so many avrs are limited in the number of channels they can process, or in the case of onkyo, unable to simultaneously decompress TrueHD/DD+, run Audyssey, and render Atmos. I know reading the pdf about mixing for atmos, When talking about their spatial encoding for home atmos (basically grouping objects that are nearby to reduce the number) it had to do with the reduced processing power in AVRs.

Supposedly, atmos for the cinema can have data rates going as high as 30-100mbps. That’s a huge chunk of data to process in real time.

 

[panteragstk]

We must be getting the shaft from avr manufacturers if their DSP chips are so weak that so many avrs are limited in the number of channels they can process, or in the case of onkyo, unable to simultaneously decompress TrueHD/DD+, run Audyssey, and render Atmos.

Where is this info coming from?

 

[AcuDefTechGuy]

Object based audio is the biggest improvement to multichannel audio since discrete 5.1, and those who have experienced a proper setup will agree that Atmos certainly imparts the same major leap in benefit as 5.1 did.

It seems like most of the big theaters around me use ATMOS in their primary screens. So I've experienced ATMOS many times now over the last 2 years in Oklahoma City, Dallas, and LA.

I would say that going from 2Ch stereo or Dolby ProLogic to Discrete 5.1 DD and DTS is like going from 480p to 1080p.

I would say that going from Discrete 5.1 DD/DTS to ATMOS is like going from 1080p to 1081p.

The ONLY thing I feel is different with ATMOS so far is that the Surround Sound is louder.

The dialogue isn't any clearer, the action in the front isn't any better, and the bass isn't any better. The surround sound is just louder.