I feel as though this is, perhaps, being overcomplicated.
The simplest solution, it would seem to me, are 5 or 7 speakers as normal, Front Heights, and one more pair of speakers that play double duty as Surround Height/Top Middle speakers.
Let's start with Auro-3D in the home, since that is probably the easiest to understand. On multiple occasions, Wilfried Van Baelen has stated that for the smaller room sizes typically used for home theaters (and I'm talking "smaller room sizes" as compared to a full-sized cinema or auditorium), he feels that a standard 5.1 speaker setup at ear level plus "quadraphonic heights" is the best way to implement the home version of Auro-3D.
So we place our Front L/R, Center, and Surround L/R as normal. Then we place four more speakers at 30 degrees elevation directly above the Front L/R and Surround L/R.
That is quite easy to understand and visualize.
Now, let's go back in time a little bit to look at some of the "expansion" listening modes that were in use before Auro-3D ever hit the market. If we consider Dolby Pro Logic IIz, Audyssey DSX, DTS Neo:X, and Yamaha CinemaDSP, every single one of them made use of "Front Height" speakers.
Now, while the exact placement guidelines for the "Front Height" speakers varied somewhat, all of them gave enough flexibility that the placement demanded by Auro-3D could be used.
So let's really simplify this:
We're going to start with standard 5.1 speaker placement - Front L/R, Center, and Surround L/R.
Now we are going to add one pair of Front Height speakers. We are going to put them directly above the Front L/R speakers at a 30 degree elevation.
Boom. We just created a 7 speaker layout that is compatible with every immersive audio format (including Dolby Atmos, which I purposely haven't mentioned yet) AND every "expansion" format.
So
the Front Height speakers are the most universally accepted speaker positions beyond standard 5.1.
So there's our starting point for everything beyond 5.1. Add a pair of Front Height speakers and you're basically in compliance with every immersive or "expansion" listening mode.
"What about the Surround Back speakers?", you ask.
They are optional in all of these formats. So let's not even really worry about them. You want Surround Back speakers? Go ahead and add them. They work with everything. Don't want to add Surround Back speakers? No worries. Not a single format actually demands them. So Surround Back speakers are optional. Don't even worry about them.
So where do we go next to keep things simple?
One option is to add Front Wide speakers. On a personal note, I am a fan of Front Wide speakers. But the simple fact is that they aren't really widely (pun intended) supported.
Actual Dolby Atmos soundtracks can make use of Front Wide speakers, but only if an audio object happens to be placed near that speaker location. The instances of a Front Wide speaker making any sound during a Dolby Atmos soundtrack could easily be very few and far between.
One would assume that actual DTS:X soundtracks might also be able to make use of Front Wide speakers. But again, only if an audio object is actually placed there in the mix.
Auro-3D does not use Front Wide speakers.
So then it's down to the "expansion" and upmixing listening modes. Audyssey DSX and DTS Neo:X make use of Front Wide speakers, but nothing else does; not even the Dolby Surround Upmixer.
So as much as it pains me to say it on a personal level due to my own preference, it simply doesn't make a whole lot of sense to prioritize Front Wide speakers.
So after all of that reasoning, we basically have two more speakers to position somewhere in the room.
We start with standard 5.1, we add a pair of Front Height speakers. Now we are going to expand to 9 speakers total. Or, of we've decided to make use of the optional Surround Back positions, we are going to expand to 11 speakers total.
And here's the only place where we need to make a compromise.
Back at the beginning of this post, I started with Auro-3D. If you want to adhere to Auro-3D, then you are going to position these last two speakers directly above the Surround L/R speakers at a 30 degree elevation to create Surround Height channels.
Now, Dolby's speaker placement guidelines for Atmos at home are well laid out in their Installation Guide:
http://www.dolby.com/us/en/technologies/dolby-atmos/dolby-atmos-home-theater-installation-guidelines.pdf
But that's way more complicated than it needs to be.
All we really need to do is to look and see if there are a pair of speakers anywhere in those Dolby Atmos guidelines that almost line up perfectly with the Auro-3D Surround Height speaker positions.
And there are! The "Top Middle" speakers in a Dolby Atmos setup go directly above the Surround L/R speakers, they just happen to be spread apart the same distance as the Front L/R speakers, which means they would typically end up somewhere on the ceiling.
So now we have a simple choice - if we think we will be listening to more Auro-3D content than Dolby Atmos content - or if we prefer the Auromatic Upmixer to the Dolby Surround Upmixer - then we will adhere to the Auro-3D speaker placement and put these last two speakers directly above our Surround L/R speakers at a 30 degree elevation. Auro-3D and Auromatic content will now be heard exactly as intended. And Atmos and Dolby Surround content will be slightly compromised, but not drastically. The Front Height speakers are an entirely supported speaker position, and we will simply tell our AV Receiver or Processor that our second pair of "Height" speakers for Atmos and DSU are "Top Middle" speakers. They just happen to be a little bit farther apart than what is laid out in the Atmos Installation Guide. But it's a fairly small compromise, to be honest.
On the other hand, if we will be listening to more Dolby Atmos content than Auro-3D content - or if we prefer the Dolby Surround Upmixer to the Auromatic upmixer - we will make sure that these last two speakers go directly above the Surround L/R speakers, but they are the same distance apart from one another as our Front L/R speakers. And that distance apart will most likely mean that these Top Middle speakers end up on the ceiling. For Auro-3D and Auromatic content, the Surround Height information will be slightly compromised. But again, really not that much.
And, of course, we could always split the difference and have these Top Middle/Surround Height speakers be a little wider apart than what Dolby would call for, but a little more overhead and closer together than what Auro would call for. So a slight compromise for both, but not a large compromise for either.
And that's it!
So to summarize:
- Start with standard 5.1
- Add a pair of Front Height speakers directly above the Front L/R speakers at a 30 degree elevation
- Add Surround Back speakers if you want - or don't. They're optional.
- Add a pair of speakers directly above the Surround L/R speakers that will act as Surround Heights for Auro-3D and Auromatic, as well as Top Middle speakers for Dolby Atmos and Dolby Surround Upmixer. Put them at exactly 30 degrees elevation if you strongly favor Auro, or put them the same width apart as your Front L/R speakers (which will most likely mean they end up on the ceiling) if you strongly favor Dolby. And if you like Auro and Dolby equally, split the difference for a slight compromise to both formats.
What gets left out with this approach?
- Well, we've left out the Front Wide speakers. But many of the current AV Receivers and Processors allow you to physically connect 13 speakers and then basically select which 11 out of those 13 are ever playing at one time. So you can still have the Front Wide speakers physically in place, and then only ever make use of them by selecting either Audyssey DSX or DTS Neo:X as your listening mode.
- The "Rear Presence" speakers for Yamaha CinemaDSP are also left out. But that is literally only one brand that ever uses that listening mode.
- The "voice of God" speaker is left out. But Wilfried himself has said that it's the least important speaker by quite a large margin.
- Dolby Enabled Upward-firing speakers or Modules. They only work for Atmos and DSU, so there's no way they can ever be "universal". Dolby Enabled speakers or Modules only make sense if you're only ever going to use Atmos and DSU, and you're never going to use any of the other immersive audio or expansion or upmixing listening modes.
Lastly, we don't know for 100% sure that DTS:X will work perfectly with all of this. But given their close relationship with Auro, and the fact that they have consistently promoted being a more speaker placement agnostic format, I find it very difficult to believe that DTS:X will not be able to make use of Front Height speakers, or that something akin to either the Surround Height or Top Middle positions will not be an option.
So there you have it: my simple solution for a "universal" speaker placement layout. 5 or 7 speakers as normal, Front Heights, and Surround Heights/Top Middle speakers.
- Rob H.
