Michael Heiss explains how the right layouts and codecs keep every corner covered 'under audio arrest'.
If you’ve ever watched a movie or TV show featuring a police chase, at some point you’ll see a character yelling: “Come out now, WE’VE GOT THE PLACE SURROUNDED!”.
The success of the crime fighting mission usually comes down to the number of good guys surrounding the place. And whether they can be observed, of course.
In a peculiar way, the success of your mission – getting the sound out – is similar. How do you, our force commander for the purpose of this article, anticipate the client’s needs as you surround the place?
I’m talking how many speaker positions you need, whether they’re fed as channels or objects, and more.
Thus, not to belabour a bad pun, let’s get ourselves locked into surround sound and evaluate what might be coming our way post-CES and ISE.
Origins of surround
Some might say it all started with two-channel sound, or Disney’s early experiments with Fantasound in 1940.
And while the latter may represent the conceptual birth of surround sound, Dolby Stereo marked its scalable launch in the mid-70s.
This technology used matrix encoding to fit four channels (Left, Centre, Right and Surround) on to a two-channel optical film track, allowing theatres to reproduce immersive sound from a single print.
On the home audio front, the technology became Dolby Surround and later Dolby Pro Logic, preserving the brand’s cinematic lineage while making surround sound practical for consumers.
The big move came in the 90s, when things finally went digital: discrete 5.1-channel playback arrived through Dolby Digital and DTS, bringing multichannel audio to both cinemas and living rooms.
The next two decades got us where we are today. But when considering an immersive or other audio system, there is much (if you’ll pardon one more pun) to decode.
Situating the sound
Let’s start with two elements that work together: the number of speaker channels and their placement in the room.
You’ll want a 5.1 system for a true surround experience, unless you’re intentionally choosing a simpler setup like a 3.1 soundbar.
In a 5.1 system, you’ll have the LCR locations plus surrounds and a subwoofer; note that I’m referring to channels, which are different from the actual sound emitted by each speaker.
This is where the important decisions begin. For example, what is the recommended placement for the surround-back speakers? If you upgrade to 7.1, you get both surround-back channels, giving you even more immersive coverage.
You’ll want a 5.1 system for a true surround experience, unless you’re intentionally choosing a simpler setup like a 3.1 soundbar.
These setups will work with basic surround formats, but with contemporary immersive systems like Dolby Atmos and DTS:X, the number and placement of speakers become more critical.
Dolby Atmos-enabled home theatre system, credit: Dolby Newsroom
Immersive systems have the advantage of being object- as well as channel-based.
As you’ll probably know, this means sound isn’t hard coded to a specific location: we’ll use the example of a spaceship landing in a movie scene to illustrate the point.
Channel-based systems distribute the sound exactly where the mixer placed it, regardless of the number of speakers or the direction of the sound.
Meanwhile, object-based systems assign sounds to positions in 3D space and metadata tells your receiver where each sound should appear.
Then the codec in the processor, AVR, or soundbar registers your speaker layout to drive the sound across the room.
Considering client needs
Those points are important not just for installation, but also when reviewing or upgrading an existing system.
Asking clients about the media they consume reveals which codecs their sources use and can influence system design significantly.
For example, Dolby Atmos has wide adoption among content providers and devices, making it almost essential for home theatres.
Asking clients about the media they consume reveals which codecs their sources use and can influence system design significantly.
After more than a decade in cinemas and home systems, Atmos allows flexibility in speaker placement: you simply tell the system where the speakers are, and it handles the rest.
DTS:X offers similar capabilities, with particular strength in Blu-Ray content.
Specialised formats
In EMEA markets, Auro-3D has gained something of a foothold in music content.
For true audiophiles, ensuring Auro-3D compatibility might be important but it does introduce some potential wrinkles.
For example, Auro-3D supports high sample rates (up to 192kHz) in production.
When that’s carried through to the content distribution, you want to check the DAC section of the AVR or processor can handle them.
Additionally, Auro-3D emphasises vertical sound presentation which especially benefits from height channels – potentially including a centre height or “Voice of God” speaker.
It’s always best to do some advanced codec and client research to ensure your installations deliver what’s expected of them.
Beyond movie content
Much of our discussion has focused on movies, but to complete the surround circle, there are some other codec and system options you need to consider – particularly for music-centric clients.
Speaker preference and room constraints will clearly govern placement, especially for height channels which usually lead to in-ceiling installs.
It’s always best to do some advanced codec and client research to ensure your installations deliver what’s expected of them.
But when this default choice isn’t possible, Dolby Atmos-enabled speakers provide an alternative.
These speakers use upward-firing drivers to bounce sound off the ceiling, creating a 3D immersive effect: a great solution for what would otherwise be an installation issue.
Upsampling legacy content
Back in the early days, manufacturers made a big deal about converting two-channel sound into “surround”.
But for many, the conversion often produced disappointing results.
Today, modern DSPs in AVRs and processors couldn’t be more different: they enable sophisticated upsampling to enlarge the sound field.
Non-encoded material, older 5.1 content and TV shows can be expanded to fill all speakers, including height channels.
The main candidates include Dolby Surround Upmixer (DSU), DTS Neural:X and Auro-Matic.
For the most part, a product with either the Dolby or DTS immersive systems will have these, but it’s always best to check for the client.
Music-focused formats
Before leaving music behind, we must address the possible requirement for Sony 360 Reality Audio (S360RA).
Unlike the upsamplers that many use for music, S360RA is an encoded format.
This means the stream must have it there; you can’t get the benefit otherwise. Immersive and object-based, this is primarily intended for two-channel headphone or earbud playback.
From someone with firsthand listening experience, it certainly works.
For S360RA, sound engineers arrange vocals, guitars and drums in a spherical space. Credit: Sony Press Centre
And while niche, it remains present on many Sony music tracks and Amazon Music Unlimited, for select titles in the latter. It’s worth including if the client requests it.
Put this in the “make sure you have it if they ask for it” bucket.
Emerging immersive formats
Before making certain we have everything surrounded, it is important to mention Eclipsa.
A recent entry from Google and Samsung, it’s built on the Immersive Audio Model and Formats (IAMF) standard, maintained by the Alliance for Open Media.
As it rolls out this year it will indeed do many of the same things as the other immersive formats: channel and/or object-based sound imaging, up to 28 input channels/elements, a binaural mode for headphone playback, and all the other special positioning playback requirements.
It even has modes for VR/AR applications.
The downside is this is a very new format and adoption, as such, is still limited: as of late 2025, only select Samsung TVs and soundbars support Eclipsa, though a broader rollout is expected in 2026.
You can also look for new content sources carrying Eclipsa encoding from streaming services. Rest assured that in our coverage of CES and ISE, you’ll see any relevant updates.
I'd be remiss if I didn't mention one relatively new alternative for immersive surround sound: Dolby Flex Connect, which offers immersive playback without requiring strict speaker placement.
With either an enabled TV or soundbar as the “leader" device and centre channel, Flex Connect communicates wirelessly to the powered speakers in the room.
Using built-in mics, it maps the room’s acoustics and automatically optimises sound for the listening environment.
This makes it particularly useful for DIY setups or spaces where traditional speaker placement is difficult.
While other wireless systems exist, such as those from Sonos, Samsung, or WiSA, they generally lack the advanced calibration that Flex Connect provides.
Yes, some of you might already be saying, “Mike, we know all of this already”.
But when designing a system, it’s essential to consider codecs, speaker count and placement alongside the client’s media habits and priorities.
Movies, music, broadcast TV, streaming, physical media, new gear, upgrades and budget all shape the final design.
Think of it like baking: gather your codecs, speakers, placement and client preferences before mixing them according to the recipe, and the job specification becomes the oven where the system comes to life.
It’s tempting to rely on familiar solutions, but that might lead to the wrong design. You need to be as open as the formats are.
Having taken this update and refresher on the state of surround, you’ll hopefully remember to ask about the more obscure aspects of surround – the ones, you’ll have learnt, make all the difference.
AUTHOR’S NOTE: Some of the technologies, formats, brands and products mentioned may not be available yet or sold in your country or region. Always please check with the manufacturers and service providers for availability before specifying.
Main image credit: Dolby Newsroom