My signal path is green for the "USB-C to HDMI Adapter" and also "OS Mixer". How can I optimize my output signal path further to become lossless? Is it possible with a USB-C to HDMI adapter on a Surface Pro X? I am able to set 24-bit/192kHz audio in Windows Sound Settings as well as in Roon.
Describe your network setup
I am using a Netgear RAX43 (Nighthawk series) router with mostly default settings, minus a few minor tweaks such as disabling QoS and port forwarding the Roon Server ports.
I have a Microsoft Surface Pro X running my Roon server and client: this is CURRENTLY my primary PC. My main PC’s GPU died about half a year ago, and this Surface Pro X was a free gift…so it is now my main PC. I can get an “Enhanced” signal path at 24bit/96kHz audio with WIFI connection to my [Roon Ready] Samsung Q990F Soundbar, and I tested an HDMI output to the soundbar on my dad’s old laptop to get a “Lossless” signal path at 24bit/192kHz (which is the max supported by my soundbar), and I had the idea of using a decent quality USB-C to HDMI adapter to get the same “Lossless” signal path to the soundbar.
This is what Roon shows me:
I would like to avoid/bypass the OS Mixer if possible, and also the green dot shows for the connection by “USB-C to HDMI” at the top. Is this possible to improve or optimize toward a “Lossless” signal path?
Thank you very much for your time and possible help.
I googled and found some tips…Right clicked the speaker icon in taskbar, went to Sound Settings and then “More Sound Settings” further down the page. Then I selected the SAMSUNG audio device (Which shows correctly, the device is a Samsung soundbar (Q990F)), and then went to Advanced to disabled exclusive mode. I’m not sure if this disables ALL exclusive mode options, but I’m restarting the Windows Audio Service and also restarting the PC, then I’m going to try using Exclusive mode only in the Roon app. I’ll post results in a bit.
Audio worked fine before with Exclusive mode disabled in Roon, but that’s not ideal.
Edit: THIS DID NOT WORK, DON’T FOLLOW THOSE STEPS!
As I imagined would be probable, Roon was unable to output audio with Exclusive Mode ENABLED for Roon device settings AND DISABLED in Windows Sound device properties.
So far, I can only get audio at the Soundbar using NO Exclusive Mode. As such, the signal path shows “OS Mixer” and is green in signal path instead of blue/purple.
These are my current settings that WILL output audio, and show all lossless signal path except for the OS Mixer being used, which results in a green dot in the signal path.
I’m reproducing the no audio situation by enabling “Exclusive Mode” in device settings for Roon → USB-C to HDMI Adapter → Soundbar and playing the track “You’re All I’ve Got Tonight” by The Cars.
If I disable Exclusive mode, audio works but sounds thin and not high quality compared to a Roon Ready direct WIFI connection to the soundbar. I’m going to try lowering the settings to 24bit/96khz in Roon and Windows Sound Settings and update if that cleans up the audio…the adapter may be struggling with a higher bitrate that is not natively supported.
I checked Google and Anker’s product page for the device and see no mention of audio bitrate specs. I DID however find a similar alternative brand USB-C to HDMI adapter for sale on Amazon that does list 24bit/192khz audio capability, and it is only $8 more than the one I got. I have an Anker A8312 currently.
Basically, from what I’ve found and experienced after getting a functional signal without Exclusive mode (sad), the sound is not as rich or dynamic as using the Roon Ready WIFI direct connection to the soundbar. I’m assuming I got an adapter that can’t support high quality audio, but it does function.
With the adapter, the mids/treble frequencies are reproduced alright but the low end frequencies are VERY underwhelming. I have a dual 8" subwoofer for the unit and in any song the bass is much more present and full sounding by avoiding the USB-C → HDMI path. I cannot currently go to a volume where I can compare the sound of the same track via both methods to fully give feedback if it is only missing bass frequencies while retaining quality mid/treble (I’d imagine there is a loss of high treble also), and I do not have signal or frequency measuring equipment..Just going by ear.
I will buy the 24bit/192kHz rated adapter in a week or so and provide my results if the signal is clean and fully functional. The adapter I found that shows support for this bitrate is a Zeskit TCHD23F, but I can’t recommend anyone get it unless they want to try it for testing purposes only. It could be a waste of money if trying to achieve HDMI bandwidth and high bitrate signal; I plan to test it when I’m able and provide results.
Thanks for the support.
EDIT: Just out of curiosity, I’m going to try a 192khz signal from my iPhone 16 Pro Max usb-c output using Roon Arc. It may have better ability to process signal than my Surface Pro X’s “OS Mixer” being the generic Windows audio driver.
EDIT 2: Lossless signal works flawlessly outputting from my iPhone.
But, the low end is still missing a lot of depth and fullness. The mids/highs sounded great, but I didn’t get to a section of song with cymbals or any high frequency notes for testing high treble. Maybe if I get the 24bit/192khz rated adapter my setup will be optimized for HDMI signal pathing. My current assumption is that this adapter was made mainly for video output and only supports audio at a basic level.
Just to update, I fixed the OS Mixer problem with ASIO4ALL. The output is lossless from Surface Pro X → USB-C to HDMI → Soundbar…just not a super high quality sound and missing some low frequency ranges.
I am still very interested in trying the other brand (Zestik) USB-C to HDMI adapter that specifically states having 24bit/192kHz audio bitrate support and maybe that will clear up the sound and fill in the lower frequency range…I’m assuming that if the adapter specifically notes support for 24bit/192kHz audio it will have better audio passing capabilities.
I do not know the technical aspects of how the adapter is handling and sending the signal to the HDMI cable…but at least I got it to function as a lossless signal path with this output method on a PC.
