Atmos Adventure

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JonFo

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Now that I have an Atmos capable pre-amp (Marantz AV8802A), I finally got around to planning and doing an Atmos elevation speaker installation.

Selecting a speaker for this application was a multi-month process, as there are not a large number of options yet, and I wanted to get as effective a solution as possible, because ‘moving’ a speaker on the ceiling is rather a chore.

Matching the MartinLogans was another concern, and while I considered the ML Architectural series and some box models, I finally came down on the side of preferring to go with coaxial designs as having more pro’s than say, having the FoldedMotion tweeter.

Atmos elevation speakers have some pretty unique requirements, first is a controlled 100 to 120 degree conical dispersion pattern. Second, is good point-source, time-aligned mids and highs, which basically only coaxial speakers nail.

After researching many options on coaxes, I came down to liking KEF and JBL as my options. In the end, I picked the JBL SCS8 as my elevation speakers.
I believe KEF is probably the ‘HiFi’ answer, but the JBL is specifically designed for this application, has great efficiency and very good mounting flexibility.
The aesthetics work for me, since my ceiling and the first foot of sidewalls are painted flat black. Stuff just disappears up there ;)

The other thing that swung it for me is that some of the highest regarded demos at CEDIA and other shows rely on this unit. My local Dolby Cinema also uses the SCS line for elevation speakers and I’ve always enjoyed the results.
So I have four of them in my garage, waiting to be mounted this weekend.

I’ll document the adventure of installing them in this thread. Plenty more to come along with plenty of pics and measurements.

So here is a pic of one of the new SCS8's in front of my Monolith. The SCS8 is a big unit, but Monoliths makes anything look small.

JBL-SCS8.jpg
 
This is awesome, I've been waiting for someone to post an ATMOS installation. I have a Marantz 7702mk2 and also thinking of adding ATMOS/DTS-X speakers. I have rather low ceiling (7.5') so ceiling speakers might sound localized. Can you please provide the room dimension for your install where you plan to put the ATMOS speakers? Thank you in advance!

Trey
 
One of the challenges of Atmos is where to place the elevation speakers, as coverage of the main and guest seats are important. Also, how they blend in with the rather large and tall panels of my MartinLogan set are another unknown. Most guidelines for Atmos elevation speaker positioning assume point source main speakers, not 6’ tall planars.

So rather than guess at where to mount and screw them into the ceiling, as usual I’m going to measure, adjust and re-measure until it’s just right for this room.

So, how to do that with stuff that’s supposed to be 10’ up in the air?

Well, I had an idea, and we’ll see how well that works out over the weekend, but here’s the concept:

  • Mount the SCS8’s to lighting T-bar tripods used in musical gigs.
  • Move them around and measure, listen until I get just the right results
  • Measure location and mark off final ceiling mount targets
  • Permanently mount to ceiling

See, easy ;)

So I also received four of these Monoprice Lighting Stands tripods this week to use in this testing phase

6018001.jpg
 
.. Can you please provide the room dimension for your install where you plan to put the ATMOS speakers? Thank you in advance!

Trey
It is a 26 X 15 X 10' room, I detail much more about it at my site

So even though the SCS8 hangs down a good bit, I expect the driver will still be above (or maybe straddling) 9' in the final ceiling mount locations.

BTW- My site is falling behind in relation to my latest gear. I'm in the middle of converting it to new format and platform and it's taking me forever to finish that. Something about new toys showing up pre-empting web page layout ;)
 
You need to think about ML Vanquish. They are aewsome��
 
That's going to sound awesome in your setup, Jon. Your room has come a long way since I was last there. You still got that three-eyed behemoth sitting in your sweet spot?
 
Very nice Jon ........you 'are' the gadget man !!
 
That's going to sound awesome in your setup, Jon. Your room has come a long way since I was last there. You still got that three-eyed behemoth sitting in your sweet spot?

Hi Rich, the old dinosaur is gone. I replaced it in late 2013 with a JVC DLA-4810 (the pro version of the X55) and what a change!

Love the added light while still retaining great blacks.

Now just waiting for the Laser-illuminated PJ to come down in price ;)

The sound is amazingly better than when you visited, the added room treatments, improved room correction and a second sub all contribute an even better soundstage. Once I finish the Atmos setup, you need to stop by for an update.
 
This is awesome Jonathan. I'm a bit behind on the atmos stuff. do we have Blu-ray Discs encoded with atmos? Also, does the marantz take a Dolby digital signal and try to convert to atmos? That seems tricky to say the least. :). Would your height channels just stay silent for a typical DD disc? I didn't see - are you doing 4 height channels?

Sounds really exciting. Keep us posted!! Tim
 
Progress was slowed this weekend by work, so maybe a bit of progress will happen this week if it's slow.

^^Tim, I'm deploying four height channels, as the room is long and there are two rows of seating to cover.

Atmos is an extension of the Dolby TrueHD format, so it is fully backwards compatible with existing players and receivers that can pass and decode that sound format. Receivers/pre's that do not understand the Atmos parts just ignore it. Plenty of BluRay releases include an Atmos-encoded sountrack if the original movie was mixed that way.

Atmos-capable receivers/pre's of course can play an Atmos-encoded soundtracks and power the elevation speakers, and they can also 'upmix' regular 5.1/7.1 soundtracks into an immersive soundspace that utilizes the heights. That is called Dolby Surround Upmixer (DSU), and that is a user-selected option. Depending on source it works either very well or is somewhat cheezy, but works well enough most users leave it on all the time.

I did find time to work on the diagrams for target placements to test, so will post those in the next day or two.
 
It is interesting.... I think this is great tech... I never seem to see movies come on with the Atmos splash screen at the beginning.... I thought this would be something that every movie would come out with as the defacto standard.... I couldn't say for sure if I have actually experienced Atmos....since movies that I go to see never seem to identify it as Atmos encoded.... The theater I go to is fairly modern as well....
 
OK, Finally got some time to work on this project today. So we'll start with the diagram of the proposed initial test locations.
These give angles to both rows that fall within the Dolby guidelines, while also fitting my room constraints (HVAC outlets being one issue).

The diagram still has the sidewall acoustic treatments depicted, as I used them as a guide along with measurements for positioning.

AtmosPositions.jpg
 
And here's a pic of the Right front elevation SCS8 speaker mounted on the lighting tripod, giving me flexibility to test multiple locations and angles.

Man, the manual labor of getting the wires run, setting up the tripods and all that is much bigger than expected. Idea sounded good, but now that I've got into it, I should have hired some help :duh:

Tomorrow I set up the rear tripods and speakers, and actually start to test.

Or maybe Santa will magically get it all installed in the perfect locations and I'll just be able to enjoy it as soon as I get up ;)

AtmosTest1.jpg
 
Santa did NOT do my setup, so guess what I did first thing today?

Now that the physical setup mostly done, with the rear tripods and speakers set up. It was much easier now that I had practice and also one less foot of height, as they are up on the riser.

Still looks messy, as I've just draped the wires, and for the rear, not even used the right color wire, I'll do that once I permanently mount the brackets to the actual ceiling joists. Turns out the 'high quality' Monster cable I put in the walls 16 years ago during construction is corroded, so I'll be running fresh wire (inside) to the back tops

Next step: run Audyssey Pro and check it out.

Pic of the left rear SC8, in context with the PJ and the rear Sequel (and all the acoustic treatment).

AtmosRightRearTest.jpg
 
Man, as my wife reminded me, it takes HOURS to set up and configure complex systems like this one.
So after reconfiguring the Marantz AV8802A preamp for the new speakers and layout, I ran a basic Audyssey measurement just to ensure the unit had the right config. I then broke out the big rig measurement system (mic stand with isolated holder, calibrated mic, XLR cables, power Mic pre-amp) and ran an Audyssey Pro calibration. I also applied a custom curve before final filter calculations. Once the calibration was loaded, I ran a few tests.

I had just received the DTS-X (DTS version of object-based immersive audio) sample disc, so ran those. Most blown away by Cymatics music video. The immersive audio on movies and music was pleasant.

We then watched our first Atmos movie, Tarzan, where the immersive soundfield is put to good use in scenes where they are swinging through the trees.

Overall, the overheads never draw attention to themselves, there is just a much bigger / taller soundfield. Although any HT with 6' tall MartinLogans already has a 'big' soundfield, the addition of overheads does allow sound to move above the 6' mark.

I need to sample many more tracks, as I'd like to validate just how well the current positions can image an object directly overhead. I have a sense the tops might be tad too separated right now. But these were laid out following the existing guidelines.
 
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And my gut sense was correct, the top fronts were both too far forward and a bit too separated. So taking advantage of the movable mounts, we re-positioned them to be 1' (one foot) further away from the front wall and about 4" (four inches) further away from the side walls.
I then re-ran yet another Audyssey Pro 8-point calibration and re-tested the results. Seems a bit better, but Atmos is actually pretty subtle (except for one demo track), and before-after comparisons are tough. Plus, I was definitely in the ballpark before.

Will update this thread with a fresh drawing and more impressions of the new locations after listening to a couple of movies.
If it passes muster, then I'll move on to the permanent mounting of these.
 
Jonathan

Have you got the position nailed down? If so where did they end up. As you know Iam in the beginning stages of adding Atmos height speaker.

Brad
 
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Jonathan

Have you got the position nailed down? If so where did they end up. As you know Iam in the beginning stages of adding Atmos height speaker.

Brad

Brad, finally got some pics of the theater with the overheads installed. I still need to update the diagram with final measurements, but it's pretty close to the original plan.
Positions moved a few inches forwards or backwards based on exactly where the ceiling joists are, as I needed to screw in a long lag bolt into something solid.

Here is a fisheye lens pic of the rear of the room where you can barely see the two rear top speakers.

LF HT Rear Fisheye.jpg

The benefit of having a full foot of black edge above the soffit helps totally hide the speakers and all the acoustic treatments up there.
 
And this is a pic of the right rear top JBL SCS8 speaker

Left rear top Atmos spkr.jpg

And a closer view:

Left rear top Atmos - close (1).jpg
 
And the front right top, notice the patch of gray material between the U-bracket and the ceiling, that is some drawer lining material that damps the interface between the metal bracket and the drywall ceiling. Little things add up.

Also, you can clearly see that it's a coax driver.

Front right top Atmos spkr (1).jpg
 

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