Optimized Center Channel

@traubr you have an awesome set up for HT.  Congrats on the 16, that’s an end game amp.  I’d be hard pressed to think the issue is your gear.  As others have recommended, running the center in Phantom mode is a great idea, that’s the first thing I would try.  You might really like that change, if the Coda is used in your HT set up to run the L/R speakers the dialogue would now be coming from the best speakers and amplification you have in your set up.  You could also try pulling the center out and placing it more in the room on a stand, then swapping it out for another speaker in that same position.  Leaving it in that position isn’t the solution but it would highlight if the current placement is part of the issue.  You could also disconnect all the channels except the center, listen to the center, swap the center for another speaker.  If you hear noticeable differences would confirm getting another center could be a solution but unless your current speaker is damaged, would be really surprising.  You could also try different amplification, hook the center up to the Coda, see if a different amp changes anything.  Again, doubtful it would but would give you proof of concept before you by new gear.  You’ve tried everything else I could think of as it relates to adjusting dialogue on the Apple TV and also using your Marantz to boost the center channel.  I would also try taking a DVD / Blu-ray disc, compare the disc to streaming the same content, if there is a noticeable difference in how you can hear the dialogue you then will know the compression used for streaming is the issue.  I recently upgraded my Projector to a JVC 4k.  I had streamed 99 % of the movies I was watching, I got a 4 k player and the bigger difference is the sound, not the picture compared to streaming.  Noticeable improvement on channel separation, bass and overall clarity.  When you stream everything is compressed, less data is used due to bandwidth limitations / considerations.  Algorithms are used for both the picture and sound.  Could be that the combo of poor mixing during production of the dialogue and the compression during the streaming process are the combo making dialogue hard to hear.   If that’s the case, only fixes would be using physical media to watch content or buying a high end movie streamer, there are a couple out there but they are expensive and you would still be limited to Movies, content you’d buy through their service, wouldn’t solve streaming Apple TV + shows, Netflix, Amazon Prime Video, Disney Plus or Paramount Plus streaming content.

Good Luck! 

If you are using Audyssey to balance the system you might consider some manual adjustments instead.  I have a Mc AV processor and the Focal Viva center and had poor dialog using the auto setup because the relative center gain was simply too low.  You still have the variance with source material and room acoustics, but dialog is one of the easiest issues to solve. IMO your current amp and center are more than fine and should be much better than any phantom setup, especially since your LCR's are timbre matched.  As noted, the aiming of the center is important, but I believe you have this addressed.  Being slightly off center might cause some timing issues but should not be a major issue with dialog clarity.

First, allow me to say I am humbled by the contributions from all of you to help me work on this dilemma.  Sometimes it takes a community and the experience and opinions of others, which is what this Forum is all about.  I take it all to heart (well, most of it, anyway) and am analyzing and strategizing while sitting in front of the home theatre beast I have wrought.

We live our lives in context, and mine is in a 225 year old house which has its beauty and obvious warts.  With something historic (nothing worthy of a historic registry), I look at our time here as stewards rather than simply owners, doing our best to ensure it thrives another century or two.  Over the years we’ve done much to improve and bring it to current standards.  Some aspects, like my listening room, are a battle that ends in a draw, rather than victory.  There are SO many things about it that need improvement to make it acoustically acceptable, first and foremost its slightly L-shape.

I spent a great deal of time positioning the front L/R speakers to get balanced stereo sound.  As equipment has changed, the distance between them and their positioning (toe-in vs facing front) has changed, and they now sound better than ever.  I just measured and yes, the center speaker is off center by a foot.  But then, so is my listening position.  If I could, I would move my throne (prime listening chair) a few feet closer to the system and a bit to the right to be in an ideal spot.  Alas, I sit on a couch, off-centered against the back wall, and having it centered and two feet from that wall ain’t gonna happen.  Acoustic treatments on the walls or ceiling?  WAF says “ain’t gonna happen.”  I think you see where this goes.  Aging ears, tinnitus, less than perfect audio tracks… everything in context.

The Marantz itself does not have PEQ; you need either the phone app or the full-blown version of Audyssey to make and upload EQ changes.  I have the phone app and had the full Audyssey version for my previous Marantz AVR (they frustratingly do not permit transfer from one product to another even with the same owner) and found those tweaks daunting (where to start, what to change).  Any suggestions on managing that are greatly appreciated.  In my research I see that Dirac has that capability embedded, and thus might be a worthwhile Black Friday gift to myself and potential solution.

I know it’s sacrilege to suggest this but, 

https://us.kef.com/products/xio-soundbar?variant=49680916316407

@traubr  I’d like to point out two things that others have mentioned and my feedback.

First off, you’re using a modded appletv to stream. The file you’re hearing is compressed heavily in the audio department and you lose a lot of the info. It doesn’t matter what’s been done to the AppleTV and all it’s doing is polishing a turd. I have demoed that very claim hundreds of times to clients by playing a movie clip on an AppleTV then that same clip using a bluray disk and a cheap bluray player. 

Second - I would strongly suggest utilizing the Dirac feature. You mentioned the price of the mic, the MiniDSP UMIK1 is around $80. Considering you bought a highly modded AppleTV, $80 is pretty cheap. With that said, Dirac has a ton of really great tools and if you’re not comfortable in diving into them all I would suggest hiring someone that can help you. There are a ton of options of dirac wiz kids that can even work on your system remotely which works out too. 

If you are wanting to get the very best audio and video out of your system and still stream, there’s only one option and that’s from a company called Kaleidescape. Their files are a true 1 to 1 bit rate to the original. Below is a link to their player, scroll about half way down and you’ll see a graph comparing an appletv to their file. I’d suggest finding a dealer close and look into it further if you’re interested.

https://www.kaleidescape.com/strato-movie-players/