How to create a Dolby Atmos 12.4.6 using multiple receivers

[romeodepaola]

Hi there, this is the my first post in this forum!
I am planning to make a 12.4.6 Dolby Atmos home cinema room using multiple receivers, and I would start using 7.2 receiver adding the other speakers and the other receivers (adding a 11.2 to the my 7.2 I should make a 12.4.6 ) in future.

I have find in a large electronic store here in Italy called "Mediaworld" the 7.2 receiver YAMAHA RX-V583 for €369, and the 5.1 speaker YAMAHA NS-PB150 for €159, that I would use them now in the normal singular receiver configuration, and in future (when I will add the speakers the the other receivers) use this 7.2 for the rear channels only.

You think that it's a good idea or not ?
I can add other receivers with this 7.2 models ?



Thanks in advance for the answers!

 

[Rocky Bennett]

Using your nomenclature, that system would have 4 sub-woofers and 12 surround sound speakers 6 Atmos enabled speakers. Although a system like that is technically impossible, you might be able to jury-rig one but it would sound terrible and require an extremely large room. Dolby does not work that way.

 

[romeodepaola]

Ok, and you have a suggest of how make a system with wore than 11.2 speaker ?


Thank you.

 

[Rocky Bennett]

Yes, surround sound. It will work better than using Atmos.

 

[Rocky Bennett]

7 speakers spread out in front and four speakers spread out in back and 2 sub-woofers. Boom!!!! You have an 11.2 system. Might not sound too good, but it will work. The time phase distortion on a beast like that would make it very uncomfortable to listen too, but you do it if you want.

To much distortion to really enjoy.

 

[Rocky Bennett]

Are all of your speakers matching, or at least have matching drivers?

 

[americanaudiophile]

You can't combine receivers in the way you suggest.
You need to have a single processor capable of decoding the total number of channels you need. You could use a receiver with a 5 or 7 channel direct input as an amp to drive channels created by another processor but you can't combine processors. You would just get duplicate channels.
The maximum number of main channels is 7 (3 front, 2 side, 2 rear). Each channel could have more than one speaker but usually makes things worse unless you are in a really big room and have a lot of chairs. Even then using dipole type side speakers can spread the surround effect to cover a wider area with less hassle.
Bass in home theater is 1 LFE channel so a .2 receiver usually just has two mono subwoofer outputs. Saves having to use a splitter. It is possible to use a subwoofer (or large speaker) for each channel. When you set the channel to 'large" you are telling the receiver to send any bass that's not in the LFE channel to that speaker rather than combining it with the LFE bass and sending it to the one or two LFE subwoofers. It would be a 7.1. or 7.2 with all channels full range.
You can have many Atmos channels (up to 16 in a home processor) but you need a processor or receiver capable of creating that many channels. Usually it's to spread the Atmos effect accurately over a larger area than most people have. 4 is usually fine. That would be a 7.2.16 for instance.
Getting better quality gear is better than just getting more gear.

 

[Rocky Bennett]

To the OP, What americanaudiophile said is exactly what I said. For example I own a 7.1 Matthew Polk Monitor surround system for my living room, a 2.1 Paul Barton speaker system for my computer and a nice pair of Martin Logans for my studio. All told I do have 11.2 speakers, about $15,000 worth of speakers, but I would never just throw them altogether to try to create one 11.2 sound system. The time-phase distortion would create an atmosphere that would be totally unpleasant.

Just because somebody could "do" something does not mean that it is a good idea.

 

[longeze]

DISCLAIMER: While I recognize that this is an old thread, it is so riddled with inaccuracy & outright false statements, that I thought I should post up anyway, for the benefit of anyone interested in this subject who happens to stumble onto this thread.

Short answer is YES, you CAN use multiple ATMOS receivers or preamps to add additional channels - up to ~13 for typical mid level consumer audio gear such marketed by Denon, Marantz, Sony, Yamaha etc.

A little background info: ATMOS for the home typically consists of a "bed" layer of 5,7 or 9 channels at or below ear level AND 2,4 or 6 "Height" or "Top" channels placed above the listener. There is normally also 1 or 2 subwoofer channels available. So called "Wide" channels are usually shared with one of the "Height" or "Top" channel amplifier or preamp outputs. So, the manufacturers usually force you to choose between either a 2nd "Height" channel set or "Wide" channels. By Using two ATMOS recievers, you can have both front & rear "Heights" AND "Wides". You can also add "Middle Top" channels to a x.x.4 system to get x.x.6, although there is "some" overlap doing it that way. Now on to the other matters...

No, you don't need ATMOS speakers. In fact, you'll usually get a better result for those not sitting in the MLP(at the least), by using conventional direct firing speakers.

The timing & phase related objections referred to by others here, is NOT in fact an impediment, as those issues are dealt with by the auto setup software: Audessey, YACC etc. Even setting the speaker distances manually by distance with a measuring tape gives a satisfactory result, albeit not an optimal one.

There are other ways to expand an ATMOS system(even beyond 13 channels), using one ATMOS device and one or more very inexpensive or older unused receivers. Google "Scatmos" for the specifics. You can't expand the "Object" specific channels using that method, but the result is none the less excellent.

I'm currently running a pair of 11 channel ATMOS receivers to derive 13 channels in my system. I'll be adding 2 more speakers to derive 15 channels with this same setup in the near future with no other modifications required. Many others have done this as well.

As to the quality of reproduction, my system creates a true 3D sound "bubble" and is incredibly immersive & realistic. It was excellent before, but adding the 2nd ATMOS receiver made it even more expansive and detailed, It is every bit the equal of anything you'll hear in a movie theater(MUCH better actually). Good luck building yours!

 

[americanaudiophile]

I am always happy to learn more about this kind of complicated subject so please correct me if I'm wrong.
As you say you can't create more object channels using two AVRs. Isn't that the entire point of Atmos to be able to move a sound in three dimensions with precision?
If you want more than one speaker to play each channel connect more than one speaker to each amplified channel of a single AVR if it can handle the load or add amps if it can't. I think that will create the effect you enjoy and is simpler than using another AVR which would require you to split the HDMI output of all your sources or use an external HDMI selector with two outputs to connect your sources to both receivers.
The receivers have to have the same input and volume control commands otherwise you can't switch inputs or adjust volume with one remote.
If the receivers aren't identical models (and maybe even not then) doesn't the volume have to change at exactly the same rate to maintain the channel balance? It's not something the designer would worry about so they might not.
When you set up each receiver (with or without DSP) it can't do anything for the problems caused by the speakers connected to the other receiver playing at the same time.
I completely agree that upward firing Atmos speakers don't work well. You need ceiling speakers to get the correct effect.

 

[longeze]

"..As you say you can't create more object channels using two AVRs. Isn't that the entire point of Atmos to be able to move a sound in three dimensions with precision?"

I probably should have been more explicit, but in the interests of brevity, I was trying to be as concise as possible. You are right to say that it is a complex subject & one that is difficult(for me) to summarize in a few paragraphs. What I was trying to convey, is that you can't implement more object channels than those provided as options for configuration on the ATMOS receivers(or preamps) in use.

What you gain by using multiple ATMOS recievers is the ability to use as many of the available options as you wish. In my circumstance, I had a Dolby TrueHD receiver that used "Wide" channels. When I bought an ATMOS preamp, I had to give those up to get rear height channels for ATMOS. Marantz made me choose between rear height or wide channels. Since I missed the sound of my wides, I added a 2nd ATMOS receiver and activated ITS wide channels, I now have both wides and 4 height channels in ATMOS. Each of those channels is recognized as unique by the ATMOS processors and objects are sent to the appropriate channels. Height channels are configured in the 2nd ATMOS receiver, but with no speakers connected, so the processor "thinks" they're there, but there is no channel duplication or overlap, since those duplicated channels remain silent.

"..If you want more than one speaker to play each channel connect more than one speaker to each amplified channel of a single AVR "

Providing more speakers for each channel isn't the point. The idea is to add channels capable of providing unique information when appropriate. Using 2 ATMOS receivers is one path to that goal. Another avenue available can be pursued with Scatmos or Zakmos as I mentioned prior. In those configurations, common information is stripped out of any two given channels and placed in a new additional channel in the same manner as your center channel is created in Dolby. It should be said, that most of what you hear in an ATMOS presentation isn't the object information, but rather the Dolby TrueHD presentation. The objects are the frosting on the cake, providing the occasional "cool" sound effect. If an object is shared or panned between two channels, instead of creating a phantom image, using Scatmos etc. will properly place that object in a created physical middle channel as intended.

"..The receivers have to have the same input and volume control commands otherwise you can't switch inputs or adjust volume with one remote. "

Many people implementing these systems use "Harmony" remotes to get around that issue. Macros are programmed into the Harmony as required to adjust gain or source selection if need be.

"..doesn't the volume have to change at exactly the same rate to maintain the channel balance? "

n my configuration, this isn't an issue. I run the outputs of my ATMOS preamps into a common processor, so I only have 1 volume control to adjust when in normal use. I get around the source selection by using the networking provided by Denon & Marantz. I just click on my computer screen with my mouse to change sources. I'm currently running the duplicate feed out of zone 2 of the primary ATMOS preamp.

"..When you set up each receiver (with or without DSP) it can't do anything for the problems caused by the speakers connected to the other receiver playing at the same time."

Maybe I don't understand your concern, but mid grade gear like we're talking about doesn't use a microphone to "listen" to channel balance ot timbre when in normal use. It only interrogates channels during training when you set it up. Since I use a Datasat, I don't bother with Audessey, but if you're concerned about that, you can either swap speakers temporarily during setup using banana plugs, or just play the channels being interrogated on the alternate reciever when required, so that the software hears "something". There is a great deal of detail published about these procedures if you Google the subject matter I referenced earlier.

"..I completely agree that upward firing Atmos speakers don't work well. You need ceiling speakers to get the correct effect. " Common ground at last! 😉) Height speakers also work well for that purpose.

 

[americanaudiophile]

Thanks for the additional info.