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! 

@traubr my recommendations on moving your center channel was as a means to prove proof of concept, figure out if the center channel itself was the issue or the placement or the amplification.  For sure realize that wouldn’t be the long term solution for you.  Sounds like you have already identified it’s not the center channel or the amplification, I would have been surprised if it was.  From a streaming standpoint, the Kaleidoscope is a fantastic option but it’s not a replacement for Apple TV or Roku if you want to watch content that is for streaming only, example being Ted Lasso or Smoke the  Kaleidoscope Isn’t an option that I’m aware of.  It actually replaces a Blu-Ray or 4k player.  It provides a way of streaming movies with the same quality as you get with physical media.  It doesn’t allow you to use streaming services like Apple TV + or Netflix or Disney Plus.  You buy the content, mostly movies from their library and it’s a digital copy that is equal to the physical media quality you would get.

@sunshdw looks like you are quite knowledgeable on the  Kaleidoscope, is my understanding of its capabilities correct?  Hoping I’m actually wrong, if it supported Netflix and other services, delivered it in a 1 bit to 1 bit conversion, uncompressed, now we are taking, would be awesome but I think the compression starts with the streaming apps / services.

@traubr sounds like you are on the right track.  If it’s your hearing, the answers probably reside in speaker placement, room treatment and understanding what frequencies you have a harder time hearing along with what make it more difficult to hear.  Some great advice you received from others was to get Dirac and have a professional calibrate your HT for you.  That’s probably going to provide the biggest leap by far relative to replacing the center or other gear.  Hearing the dialogue is more about how to tailor your system to work around your loss of hearing, which is both about knowing what frequencies you have a more difficult time hearing and what frequencies you can hear that may make it harder, overall to decipher dialogue.

You’ve got great ideas and a great approach lined up.  
 

I am curious about the Apple TV X, what are your thoughts?  Noticible difference in picture and sound?  Is it as good as physical media?  I had never heard about it prior to this thread, I researched it a bit and was difficult to understand why the mods would provide such improvements, I read threads where the creator, engineer repeatedly talks about the quality of parts, time spent developing but then says he really can’t explain why it has better audio beyond less jitter and that he has even less of an explanation of why the picture is noticeably improved.  The mods all seem legit and inline with what you would see some do in audio with digital, removing noise, upgrading the power supply.  What’s different though is you can feed a DAC a variety of audio formats along with uncompressed, lossless files.  The time you put into removing noise, jitter, in an audio only set up in theory maximizes utilization of the lossless file in its purest form.  That’s not really achievable with the Apple TV which makes it all the more interesting in finding out if it provides the improvements it claims to.  Seems like the improvements could also highlight flaws in the Audio and Video due to compression that the algorithms used for both are designed to cover up.