I am having a problem with my Nucleus Titan downsampling music intermittently using one of the HDMI ports but not the other but both are identified with the same output source. Please read on…
My Nucleus Titan is directly connected to my Denon AVR-110 via the HDMI A Output (as an example). I have correctly identified the output source of HDMI A and B both to be Denon AVR-A110 in Audio Setup.
Now, when I play a song using HDMI A, the track is downsampled incorrectly (see pic). I say “incorrectly” because if I switch to play the same track using HDMI B the track does not downsample (see pic).
If my solution was simply to use HDMI B instead as my output port then I would be a happy camper but this is only temporary. I don’t know the exact trigger but at some point HDMI B will begin to downsample the same track that it was not downsampling previously.
So at some point I try to test the HDMI A port again and it will no longer downsample so I then think ok let me switch back to HDMI A as my source output but this is only temporary as it will eventually start to downsample again with no other changes made to Roon and playing the same exact track (I’ve tested with multiple tracks of the same lossless quality).
Can anyone tell me what exactly is going on here? I know the Denon AVR-A110 is capable of playing 192khz at 24bit and I have demonstrated this is indeed occurring in the pictures attached so why does it start downsampling. Something is triggering Roon to downsample incorrectly. Fyi, The Denon AVR-A110 is a Roon Tested device.
Also, I have tried other music tracks with the same test and get the same intermittent downsampling issue. I have also tried to change the source output to some other model with a similar 32-bit DAC and get the same result. Though I don’t believe there is any 2-way communication between Roon and the source output for this to matter but I tried to is just to make sure the model within Roon isn’t specified correctly.
One interesting note, I can tell the downsampling will occur because in the HDMI setup on the Nucleus the PCM and MQA settings disappear. You can see this in the pics I have attached. So when I see “PCM” and “MQA” no downsampling occurs. But I have no known way of controlling when these settings appear in setup or not.
I am at a loss here. Can anyone help me figure this out?
Nucleus Titan (Stone)
Ver. Roon Server 2.0 (build 1483)
1452 Albums / 630 Artists Denon AVR-A110 (AKM 32-bit DAC)
Connected via HDMI Port A or B
Polk Audio Speakers/SVS Subwoofer
Primary Music Source: Tidal & Quboz
Does that mean you have two HDMI cables from the Titan to your Denon? What happens if you remove one cable? Or, am I not understanding the HDMI A vs HDMI B thing?
Also, did you make sure you have no MUSE down sampling going on?
I only connect one HDMI port using a single HDMI cable to the Denon receiver at a time. But in Roon I can quickly test the other HDMI port that is not connected just for testing purposes.
The 32 bit DAC is irrelevant. It is 32 bit internally only. It does not accept a 32 bit input, as there is no means to input 32 bit audio to the AVR or any HDMI device.
This is almost certainly an HDMI handshake issue. Try restarting both Nucleus and AVR when it occurs.
Thanks for the reply. I’m glad someone else is seeing the same issue. My only disagreement on it being a handshake issue is that I can try HDMI B with no cable connected and it gets the same result meaning intermittent downsampling
So if we eliminate the cable being the issue which eliminates any communication or handshaking issues then it comes down to either the Nucleus hardware or a bug in Roon software.
How can I get someone from support to look into this. I’ve done all the testing I can think of on my end and have been able to narrow down the problem as stated in my original write-up. Can I get support to review my logs and/or anything else?
Your request is in the support team’s queue, and will be answered when it reaches the head of the queue. The team is small (four people), so your patience is requested. Thank you for your understanding.
Can you please try to perform a “Load Defaults” on the problematic zone and let us know if it helps?
Usually, you are able to also set a max sample rate for each zone in Device Setup, it is strange that you are not seeing this as an option. Another thing you can try is to un-identify the devices as Denon and leave them as generic HDMI outputs. Let us know if this helps.
That is a handshake issue. HDMI should fail to initialize if no cable is connected at both source and sink because HDMI is a bidirectional protocol. In other words, HDMI should not work at all.
I’ve tried loading defaults and selecting generic or other sources and none resolve the issue.
I’ve discovered a very important piece to the puzzle. The Titan has two HDMI ports A and B. No matter which port you physically are connected to wherever the HDMI port is connected to this becomes HDMI A and the unconnected port is always HDMI B.
The more important discovery is that it is the connected port that is always doing the downsampling. The unconnected port is the port that plays to the original spec.
So now I have a question on handshake. Does Roon know what DAC it is connected to? From reading here in this forum it seems many people disagree with the notion that Roon had any visibility to the receivers DAC capabilities. This is not my area of expertise so I just don’t know.
The situation you face reminds me very much of a similar one I had with ROCK on a NUC via HDMI to my Denon AVR. Totally non-sense enabled options like max. sampling rates and disabled or invisible options in the roon client. All contradictory to the device’s capabilities.
I know it sounds too easy, but I couldn’t read it here. My clear solution was to always turn on the AVR first, and after this is completely up and running, turning on the roon server/Titan. Before doing so, you should also disable the currently detected HDMI devices/AVR connections.
Ever tried a different HDMI port of your AVR?
There’s nothing but the HDMI cable between your Titan and the AVR, right? And your AVR has the latest firmware installed?
Thanks for the info. Yes there is only one cable from the Nucleus to the AVR. My setup always has the AVR turning on first.
So I’ve tested another scenario where I reconnected a Bluesound Node X using an optical output to the Denon AVR. By using the optical output Bluesound uses the AVR DAC and disables the internal DAC. But doing this Roon does play at the proper sampling rates ie no downsampling on the Denon AVR.
I’m still confused how Roon determines the appropriate sampling of any music. Though many have suggested there’s a 2 way communication between AVR and Roon Titan I just don’t see how Roon is determining the specs of the AVR DAC other than when I manually specify the output device in setup on Roon.
Could it be possible that in Roon the AVR devices are incorrectly defined in setup?
Important Finding: After rereading everyone’s posts (thank you BTW) I performed one more test that identifies and isolates the root of the problem.
On my Roon Titan I removed the HDMI cable all together so neither port A or port B has a cable connected.
When I do this I can still play music to either audio source without a cable. I found that HDMI B never downsamples and HDMI A always downsamples. Both HDMI ports are setup as the same Denon AVR model in Audio Setup on Roon.
So with this test I have eliminated the Denon AVR, a handshake issue, or a cable being the problem. The problem inherently exists in the Roon Titan hardware or Roon software.
I also confirmed that on HDMI A PCM and MQA settings are missing and HDMI B does have both settings available.
One more very important point that is relevant to this problem. The problem is not just with HDMI A. If this were the case I could easily just start using HDMI B and not worry about this issue. What I found is the HDMI ports are dynamically assigned so wherever the HDMI cable is connected becomes HDMI A even if the cable is physically connected to HDMI B on the Nucleus. Because of this the downsampling problem follows me to whatever port I connect to since HDMI A is where the downsampling happens always. There is no way of connecting to HDMI B logically. I hope this makes sense as it is hard to explain.
I will wait for Roon Support to further guide me unless anyone has anything else you can recommend me to try within Roon to resolve this problem.
I have remove the HDMI cable just for testing. Therefore no music plays but I can still see if Roon is attempting to downsample or not. The Nuclues Titan had two HDMI output ports and when I do this test one output downsamples and the other port does not and all else being equal.
It doesn’t sound like anyone has any more possible solutions to this perplexing problem so I will wait for support to take up this issue and help troubleshoot with me.
Thank you all for your suggestions and ideas on how to solve this perplexing problem. I appreciate your time in helping me.
I will continue to wait for Roon Nucleus to intercede and help me further troubleshoot the problem.
Indeed, you should wait for feedback from support. They should be able to easily identify the core issue, once they took a look into your system’s log.
Have a nice Christmas time
