G3P & Atmos - How does Dolby handle an X.X.2 setup?

[Natural1]

Hi all,
I'm getting ready to add 2 top speakers to my current 5.2 set up on my RMC-1L. My space is constrained to a .2 setup, I can't add 4 top speakers. I'm working through the "hows" and "whys" and trying to understand how everything fits together, and I have a few questions...

First off, on the G3Ps you cannot enable top middle speakers unless top fronts and top rears are already enabled. The means that top middle can't be used for a ".2" Atmos setup. I knew this and I also assumed that this limitation was something in the Dolby spec, but maybe not... In looking through the Marantz 7706 manual that I downloaded a few months back, I see that top middle can be selected in a .2 Atmos configuration. Does anyone know why this can't be done in the Emotiva processors? I'm guessing there's a good reason for that.

EDIT: I'm sorry for posting incorrect info. Everything italicized above is wrong. You CAN configure "top middle" from either the front height or rear height XLR outputs as your ".2" output. Thanks to ttocs for clearing this up!

Secondly, from a Dolby processing standpoint, what happens to the information that would be present in the top middle and top rear speakers when you only have the top front speakers enabled? Is that information merged into the top fronts, or is it simply dropped?

EDIT: The question above is now largely irrelevant. When using "top middle" the sounds destined for top front and rear would likely be merged.


The reason for these questions is that I'm starting to wonder if a ".2" Atmos setup is even worth bothering with.

Thanks!

[Natural1]

And also, I think the majority of my Atmos use would be in terms of having the DSU upmix non-Atmos source material. I've heard that it actually does a good job of this in general, but what about in a .2 scenario? I would really like to hear from other G3P users that are running ".2" like this.

EDIT: Removed some misleading/incorrect info. You CAN configure "top middle" from either the front height or rear height XLR outputs as your ".2" output. Thanks to ttocs for clearing this up!

Thanks again!

[ttocs]

When I setup the system for 5.1, then go to add Top Middle, I can do so with either the Front Height or Rear Height.

You must be trying to use the Left/Right Subwoofer channels, but these are for if you are already configured with Front and Rear Tops. So just change this back to None, keep the Center Sub for Mono, and use either of the normal Front or Rear Height menu choices.

[Natural1]

Dec 5, 2022 13:23:59 GMT -5 ttocs said:

When I setup the system for 5.1, then go to add Top Middle, I can do so with either the Front Height or Rear Height.

You must be trying to use the Left/Right Subwoofer channels, but these are for if you are already configured with Front and Rear Tops. So just change this back to None, keep the Center Sub for Mono, and use either of the normal Front or Rear Height menu choices.

Oh interesting, thank you! I was going by the info in the RMC-1 user manual and I had not actually played around with it in the menu itself. I haven't even purchased speakers or amp for atmos yet.

From the manual, page 56:
Note: Certain speaker configuration options will only appear in the Menu under certain
conditions - when you are permitted to select or enable them. For example, the ability to
configure Center Height Speakers will be hidden unless you have already enabled Front Height
and Rear Height speakers. As a result, these options must be enabled or configured in a certain
order.

[Natural1]

I'm sorry for the incorrect info posted above. I edited my first two posts so folks seeing this later on would not be confused.

I'd still be interested in hearing impressions of those with a .2 Atmos setup...
Do you find that the Dolby upmixer does a good job with this?
Would you do it again?

Thanks!

[Gary Cook]

I've been running a 5.1.2 set up since the XMC-2 arrived, it is fantastic, far superior to the 7.1 set up that I had previously with the XMC-1. It's almost indistinguishable from the 5.1.4 that I tested and rejected due to space and location issues with exposed beams and a heavily raked ceiling. Most Atmos sound tracks are pretty good now, they have gone away from the some of the gimmicky early stuff. Andor is good recent example of only using the overheads when necessary so the impact when they are used is greater.

Just do it.

Cheers
Gary

[thezone]

Dec 5, 2022 21:13:43 GMT -5 Gary Cook said:

I've been running a 5.1.2 set up since the XMC-2 arrived, it is fantastic, far superior to the 7.1 set up that I had previously with the XMC-1. It's almost indistinguishable from the 5.1.4 that I tested and rejected due to space and location issues with exposed beams and a heavily raked ceiling. Most Atmos sound tracks are pretty good now, they have gone away from the some of the gimmicky early stuff. Andor is good recent example of only using the overheads when necessary so the impact when they are used is greater.

Just do it.

Cheers
Gary

Interesting. I have a 5.1.2 setup atm, but was contemplating going to a 5.1.4 after a future renovation. Are you suggesting the .4 is not worth the worry over .2?

[AudioHTIT]

I tested a uniquely reflected 7.2.2 Atmos before cutting holes in the ceiling and building 7.2.4. I felt the .2 added a lot, and the experiment prompted me to go ahead with .4. To me .2 was the most bang for the buck, and added more to the ‘bubble’ than .4, somewhat like 5.x surround contributes more than 7.x.

All this isn’t to say that .4 or .6 aren’t worth it, just that .2 is … more worth it.

[Gary Cook]

Dec 6, 2022 5:18:32 GMT -5 thezone said:

Dec 5, 2022 21:13:43 GMT -5 Gary Cook said:

I've been running a 5.1.2 set up since the XMC-2 arrived, it is fantastic, far superior to the 7.1 set up that I had previously with the XMC-1. It's almost indistinguishable from the 5.1.4 that I tested and rejected due to space and location issues with exposed beams and a heavily raked ceiling. Most Atmos sound tracks are pretty good now, they have gone away from the some of the gimmicky early stuff. Andor is good recent example of only using the overheads when necessary so the impact when they are used is greater.

Just do it.

Interesting. I have a 5.1.2 setup atm, but was contemplating going to a 5.1.4 after a future renovation. Are you suggesting the .4 is not worth the worry over .2?

It wasn't much of a decision for me, physically 4 was difficult and acoustically not ideal with the exposed beams. I did try it for a few days using a lighting gantry, but it didn't add anything sound wise. It's not like sound effects go missing they just appear from 2 locations instead of 4. That said I don't have a large listening area, the room itself is large but within the confines of the 5.1 space it's not that big. If it was a large room with lots of spacing between speakers then maybe 4 would be noticeably better, but not in the smaller spread.

My thinking is if there isn't room for 7.1 then 5.1.2 is most likely more suitable.

Cheers
Gary

[marcl]

This seems like an appropriate place to share this.  Excellent discussion on Audioholics with John Traunwieser, an engineer who does Atmos mixes.   They discuss how mixes are done differently for theater and near-field (home) … how objects are used vs bed channels, and the challenges of fidelity and positioning of objects … target home Atmos layout for mixers (7.1.4) … etc.   Always good to listen to discussion that includes Matt Poes too. He does a presentation on psychoacoustic mechanisms of elevation. 

Long-ish at 2hrs, but easily listenable at 1.5x in 80min.

[Lonnie]

Dec 5, 2022 12:59:42 GMT -5 Natural1 said:

Hi all,
I'm getting ready to add 2 top speakers to my current 5.2 set up on my RMC-1L. My space is constrained to a .2 setup, I can't add 4 top speakers. I'm working through the "hows" and "whys" and trying to understand how everything fits together, and I have a few questions...

First off, on the G3Ps you cannot enable top middle speakers unless top fronts and top rears are already enabled. The means that top middle can't be used for a ".2" Atmos setup. I knew this and I also assumed that this limitation was something in the Dolby spec, but maybe not... In looking through the Marantz 7706 manual that I downloaded a few months back, I see that top middle can be selected in a .2 Atmos configuration. Does anyone know why this can't be done in the Emotiva processors? I'm guessing there's a good reason for that.

EDIT: I'm sorry for posting incorrect info. Everything italicized above is wrong. You CAN configure "top middle" from either the front height or rear height XLR outputs as your ".2" output. Thanks to ttocs for clearing this up!

Secondly, from a Dolby processing standpoint, what happens to the information that would be present in the top middle and top rear speakers when you only have the top front speakers enabled? Is that information merged into the top fronts, or is it simply dropped?

EDIT: The question above is now largely irrelevant. When using "top middle" the sounds destined for top front and rear would likely be merged.


The reason for these questions is that I'm starting to wonder if a ".2" Atmos setup is even worth bothering with.

Thanks!

It is kind of an odd thing the way Dolby has the code setup. If you are setting up a x.x.2 then you set the .2 as front Heights and the Dolby code routes the signals internally to the middle heights. It doesn't really make a lot of sense to me either, but that is what it is. Connect them up to the Front Heights. Go into the setup menu and turn on the Front Heights. The DSP will handle the rest.

Lonnie