I don’t have a good answer to that… Data itself coming into HQPlayer is different, so the known different areas are most potential ones.
But I cannot change how Roon works. So it is not particularly useful work for me to do, I rather focus on areas where I can do something. It is something that would be more useful for Roon to do.
P.S. And I never noticed any notable differences in my setup…
halo
i have test various throughout last few years
from hearing difference between
tidal vs qobuz through roon
roon vs hqp
roon vs audirvana
disabling mqa core decoder in roon vs enabled between flac tidal qobuz
hqp vs jplay femto via bubble upnp vs roon using qoboz
with the last test ending with hqp and roon sounded same and bubble control with jplay femto sounding slightly more sterile with loss of low level detail
this did not correlate based on anecdotal reports from handful of posters
it would make more sense if hqp sound was different from roon as claimed but since not using jplay ios specifically which is just control app then this is not scientifically same
i have deemed this trial inconclusive as it does not correspond with reports
the other day i try once more hqp vs roon and i sense difference
i thought maybe tidal mqa integration as cause and log out of tidal and uninstall roon and reinstall
result after is both sound same
i concluded as such was possible due to tidal mess or bug in roon and clean install removed trace of tidal and mqa effects
yesterday i trial hqp vs roon and once again hear difference
invalidating my conclusion from previous
what do this mean
that we cannot be sure as placebo is a strong contender
if measurements cannot resolve or proper controls are in place in ones signal that anything can happen
if sound is clean one way or another
is this right or is it wrong or better or worse based on chain
with so many variables in play and settings not controlled for with reports
nothing can be certain
i can only conclude my own experience with my lcd5 that is deemed a sterile non musical headpiece
most test i have done resulted in roon being preferred
amongst tests hqp has been the leaner or lifeless player
i can imagine if one chain is lean the opposite would be preferred and if one chain is muddy or blunted in transients that a thinner or sterile player would then be preferred
what do this mean
if one wishes to reach further
one could even say hqp is intentional in making sound worse or sterile so filters have greater effect or is roon altering in some way to make different sound
which is correct
what incentive does one have in making absolute claims if the majority does not agree and results are unfounded by only a handful of users where cost is a factor
i conclude all comes down to preference and chain and even day and mood they listen
who is up for system challenge of debunking either side
What do you mean exactly by this?
How is it different if it’s a flac file how can it be different data coming to HQplayer? Does Roon decode it before sending it on? Or is it just the way they handle your api?
Mood has a massive influence on how anything sounds or even if you like a particular Artist/album when heard for first time.
As I mentioned earlier, with Roon, it decodes the source audio and provides raw decoded audio to HQPlayer. It is kind of endless stream of audio, so for example track boundaries are not visible to HQPlayer unless the format changes. One can also perform various DSP operations at Roon side if wanted, and then the output comes to HQPlayer for further processing.
Whereas with JPlay, HQPlayer Client and HQPDcontrol, HQPlayer has direct access to the source content without the control application being involved with the actual content. Same goes when you play with mConnect Player or BubbleUPnP to HQPlayer Embedded (UPnP), assuming streaming service or non-transcoding media server.
While if you use Audirvana to play audio to HQPlayer Embedded (UPnP), then it is quite similar to Roon.
So if there are audible differences, then it is most likely somewhere around this area. It could be also something of a “side channel effect”, so instead of audio data being different, it could be activity pattern difference affecting ground noise patterns or similar. Assuming for example direct connection to the DAC without galvanic isolation or a NAA (with U/UTP or optical cable).
So I don’t want to outright jump into ruling out possibilities… It is not easy to point out any particular reasons either.
Likely in my system, I probably wouldn’t be able to hear differences. But, OTOH, it is not something I’m actively trying to do. At least it is not obvious to me. In my case, Roon Server runs on a dedicated NUC with Debian 12. I have multiple HQPlayer Desktop and Embedded servers around the house that are configured as zones in Roon. All have couple of switches in between.
Jussi thanks for all of these information. Much appreciated!! Especially given you are not even the one involved in developing the roon processes and certainly you don’t owe anyone any explanations on potential differences (or no differences)
Roon sends PCM not Flac. The server unpacks the flac into PCM and sends it.
Or they have tried it and did not hear a difference. Just because one person hears it one way doesn’t mean everyone else will.
Or DSD for that matter if source is DSD…
If one has multichannel content, in Roon HQPlayer endpoint configuration one should select 5.1 output, no stereo to multichannel conversion and “channel mapping only” instead of downmixing.
This way everything comes should come unmodified to HQPlayer.
I agree. There really isn’t much else to go on this topic. Some people heard a difference, some people don’t. Subjectively some one prefers one over another. Period. Many folks who decided to try jplay are already roon lifetime subscribers or are unlikely to give up on Roon for its more extensive functionality
I agree with the previous comment - it’s up to each individual to make his or her own choice.
Thanks to Jussi for explaining the difference in incoming flows between Roon and JPlay.
Hmmm that sort of goes against what they say in the docs about HQplayer then as it’s decoding to pcm. Thanks for clarifying this.
Thanks Jussi for this post.
I am able to draw my own conclusions now for my set-up. 
P.S. I will buy JPlay anyway because it is a good alternative to Roon, when things should go south with Roon labs. 
Thx for clarifying.
I forgot FLAC is only the container and PCM is the actual data stream.
Which part where? Maybe there’s an error in some documentation. But the Roon signal path display is relatively clear on what is happening. Although it would need a bit of update for some HQPlayer status cases, but the Roon side of it should be up to date.
This bit
HQPlayer owns the final connection to the device, and Roon is just passing along a stream of bits from your media files. This allows you to enjoy the processing benefits of HQPlayer and the library management capabilities of Roon at the same time.
I read this as the original file was being sent untouched but it’s not… Still not sure why it needs to decode if it’s sending to another player architecture just seems unnecessary. But can’t see how pcm stream would sound any different to flac as it’s the same data and libflac is used to do this.
That is not incorrect, although it doesn’t mention the decoding. Or the Roon side DSP things.
Yes, the final audio data entering HQPlayer DSP shouldn’t be any different as long as you don’t have DSP being performed in Roon. This can be easily seen from the signal path display.
When Tidal was still full of MQA, this model was particularly useful, since Roon could decode MQA before sending audio to HQPlayer. And for some cases when you encounter MQA tracks, or if you own MQA tracks, it is still the case.
The model also allows you to play content formats HQPlayer doesn’t support, such as ALAC or AAC. OTOH, I don’t know if Roon supports WavPack or 32-bit FLAC while HQPlayer does, so in some cases it could be other way around.
In addition, if you want, you can perform DSP in Roon.
One thing that hopefully gets improved by Roon, is that currently volume leveling DSP cannot be performed at HQPlayer side, since metadata is not being passed to HQPlayer. And Roon doesn’t adjust HQPlayer volume according to the replay gain, even though it could do this if it wanted. So at the moment, when enabled, Roon does volume leveling DSP at it’s side before the data comes to HQPlayer. This is clearly visible in Roon’s signal path display though. And I also don’t know if Roon supports volume leveling for DSD sources like HQPlayer does, this is where it would be particularly useful to perform at HQPlayer side. I don’t know how commonly volume leveling is used.
+1 for volume leveling.
There are 3 generally accepted/known things can impact the signal going into a DAC:
USB Audio, wherein the DAC controls the clocking, makes the first irreverent, and HQP buffers would mitigate upstream jitter in Roon/source stream.
Isolation of upstream noise via Ethernet/NAA/Intona/galvanic isolation neutralizes the second.
If you have these two bases covered and you think Roon sounds worse than JPlay when feeding HQPlayer then it would suggest that either:
a. you likely have some sort of dsp/volume control enabled in Roon such that it’s not sending bitperfect data to HQP, different from what would be sent directly via JPlay
b. HQPlayer has a bug when processing Roon streams - unlikely
c. You believe that there is some as yet undiscovered form of electronic artifact/phenomena being passed down the chain from a Roon Server to a DAC.
Lots of the above comments having to do with volume leveling when comparing Roon/JPlay suggest they at least have volume control enabled. If a bitperfect stream was being sent by Roon then the volume levels would be identical. So this disqualifies any of those comparisons as being objective.
Anyone is welcome to believe what they hear, but it would be nice if they could back up their subjective perceptions with some objective foundation.
I don’t ask Roon for any audio processing, I only use it for library management.
I don’t think I hear anything, but I do hear a difference.
In the end, I don’t care about the technical reason, only the result of listening to music with my ears, my audio system and my listening room.
I’m not in any way denigrating Roon or praising JPlay, I’m just noticing a difference, which may or may not please you, it’s up to you.