Dolby Atmos Beyond 7.1.4 - 1.dio (2023.) (2023)

A little over a year ago, I started experimenting with ways to expand my Dolby Atmos surround sound system beyond the 7.1.4 limitations of current consumer hardware. My constant quest to get the best Atmos experience in my home has recently prompted me to make an additional upgrade. My home theater is so complicated these days that I actually have to use three A/V receivers at the same time to control all my speakers.

In most home theaters, 7.1.4 channels should be sufficient. While the Atmos format (like its rival DTS:X) can support additional speakers, there hasn't been much consumer demand or pressure from manufacturers. Only $37,000 for such a high-end boutique right nowTrinovska is 32 in heightWill decode more than 11 channels at a time.

However, for some of us, the limit of four height channels wasn't enough to fill the top half of the room with sound. My own home theater is a long room with lots of room behind my seats. This, combined with the low ceiling, made it difficult to convincingly reproduce the sound above my head with just four speakers (two at the front of the room and two at the back). This issue was compounded by the fact that when I was building my home theater (before I even considered immersive sound) the placement of the speakers wasn't ideal for Atmos. The speakers now go through the walls and ceiling and I can't move them without rearranging the room. That's not an option.

A better solution would be to place the extra speaker in the middle (upper center position) between the other height channels. Unfortunately, the asking price for the Trinn processor is way beyond my budget. I had to find a way to provide a similar effect to the jury at a fraction of the cost.

first try

andI wrote an article last yearI explained how I used a second A/V receiver to route additional channels up my ceiling to build a complex system (jokingly called "Zatmos"). I recommend reading that article to get a basic idea of ​​how this sort of thing is possible.

Even then, I wasn't the only one experimenting with this, and I knew my Zatmos system wasn't as ideal as I'd hoped it would be.On the AVS Forum, a member named Scott Simonian took the totalDry A/V ReceiverConsistently created the 7.1.6 configuration (affectionately known as "Scatmos"), which more closely matches the intent of the original Dolby Atmos mixer.

For a while I decided not to go that far. The complexity of installing, wiring and configuring three A/V receivers seemed like overkill to me. I feel like the results I get with the Zatmos are good enough to get me there most of the time, and I have a level of selfish pride in figuring out a way to do it with just one extra receiver instead of two Methods.

However, my attitude has changed in recent months and I have become less comfortable with Zatmos configurations. In the end, I knew that if I was going to do it, I had to get it right.

go all out

Two silly nicknames, Zatmos and Scatmos, could be more formally grouped under the heading "Dolby Atmos Extended." I want to be clear here that I did not develop the Scatmos process. Thanks to Scott Simonian and the others at AVSForum for helping him figure this out. With his permission, I just wanted to explain it here.

Because they are so complicated to install, one of the savings of these experiments is that they can be assembled relatively cheaply. While your primary A/V receiver must be a Dolby Atmos (or DTS:X) model capable of decoding 7.1.4 channel audio from an immersive Blu-ray or UHD soundtrack, the secondary receiver is not so modern. Any receiver with at least Dolby ProLogic II processing capability will do. (If you're using multiple secondary receivers, I recommend that they be identical to each other.)

With a bit of patience, I was able to snag a pair of used Marantz SR4400s for under $100 each while following ads for sale on my local Craigslist. This is a basic (or almost) Dolby Digital/DTS model from 2003 with no extras. It's so simple that it doesn't even have an on-screen menu system. I have to use only the front panel display for setup. The receiver doesn't have HDMI and can't handle lossless Dolby TrueHD or DTS-HD Master Audio signals, but you don't have to. All you need is a pair of analog stereo inputs (every receiver will have them) and ProLogic II.

The simple act of finding a place in my system to put another A/V receiver turned out to be far more difficult than I'd like. Since I didn't have enough room on the main gear rack for it, I had to remove all components, disassemble the rack, rearrange the levels, put most of the gears back in place, and reinsert. Then I had to do the same with the second shelf to add a level. My Blu-ray and HD DVD players, which used to be on the main shelf, have been moved to another shelf so that I can keep all my audio equipment together and where the speaker cables can reach it. That in itself is a huge pain.

Once that's done, here's the basic idea behind Scatmos: You want to install six in-ceiling speakers - at the top front, top middle and top rear positions. (The sketch below does not represent my personal speaker setup, but I drew it this way to show how it's doneyou shouldFinish. ) Your primary A/V receiver is set to decode up to 7.1.4 channels, configured as Up Front and Up Rear.

All four tweeter channels should be routed to the analog preout connectors on the main AVR. Do not connect any speaker wires to those channels on the main AVR. For all height channels, only the speaker wires are connected to the auxiliary AVR.

The pre-outs of the top left and top left channels go to the left and right stereo inputs of the AVR 2.

On the AVR 3, the front upper right and rear upper right channel pre outputs go to the left and right (reverse on the AVR 2) stereo inputs.

If this sounds confusing, it can be really scary trying to keep things straight when attaching cables and wires. I highly recommend that you draw up a diagram showing where you need to go.

If working properly, each secondary downstream AVR should receive a stereo signal consisting of the front and rear, and matrix the center channel between them using all the mono information common to both (similar to how ProLogic II uses the center channel way, will be separated in the dialogue below) normal conditions of the room between the left and right speakers). So you get six channels of height information out of the original four.

It is a theory, reduced to its most basic elements. In order to work properly after the connection is established, I will cover some additional difficulty settings in the second part.

Read part 2