MEASUREMENTS: Roon 1.2 (with Intel NUC 6i5SYH)

NOTE: I know that just a couple weeks ago, version 1.3 of Roon has been released and I'll perhaps look into that a bit later once some of the initial bugs are stamped out and the system matures a little. Clearly 1.3 has a few new interesting features but the basic bit-perfect playback function I trust would be the same which is what I'm aiming at exploring in this article.

Over the last few years, I have already gradually made my way across the different audio ecosystems that most audiophiles find themselves interested in. Starting with the venerable Squeezebox / Logitech Music Server system (eg. Touch, Transporter), to standard Windows PC and Mac OS X playback, to questionable software (like JPLAY and the JPLAY update), to even just as questionable OS tweaks (eg. Fidelizer), to more recently looking at DLNA streaming using low power devices like the Raspberry Pi 3 and ODROID-C2.

For today and the next few weeks (let's see how this goes), let's spend some time on Roon, another computer audio system much lauded in the audiophile press and see if we can make a few measurements and comment on some observations and thoughts...



First, my intent is not to reproduce all the usual intro articles on line... Go read up here, here, and here for background. Just know this, it's a playback system that helps catalogue your music files on the "Core" (server) machine, has an infrastructure to stream the music across to distributed "Outputs" including a software "Bridge" that can be run on computers. It also has a special relationship with Tidal to integrate the service's library seamlessly into the "Core". Like with many other music infrastructures these days, it also has "Control" software (Roon Remote) including apps you can download for Android and Apple devices.

Although Roon does a great job reaching out to many devices including Squeezeboxes and AirPlay devices, so far, this is relatively typical for modern playback systems. The "value added" piece, the part that you mainly pay money for as a subscription however, is access to the extensive metadata library so your library is tagged with plenty of potentially interesting and useful information. Things like album reviews, artist info, detailed credit and collaborators on a project. I've also seen high resolution album cover images (1280x1280) associated with my albums. And with that, there's the ability to mix-and-match with related albums that the listener may want to try. That last part of course can open up endless possibilities when one has access to huge libraries like through TIDAL.

Intel NUC on top of the TEAC UD-501 DAC loaded up with Roon and ready to play some music.

So, I decided to take Roon (1.2, build 168, 64-bit stable) up for a spin with its 2 week free trial (which one has to hand over some credit card information for) about a month back. The cost for Roon is US$119/year or US$499 unlimited "lifetime" access. And as the picture above suggests, I decided to install the "Core" on my Intel NUC 6i5SYH (some measurements and tests here) recently before I commissioned it for other work-related duties.

I. General Comments:

Installing Roon "Core" on the Windows 10 PC was a piece of cake. No issues at all and everything went smoothly, allowing me to point the program to my music directory which I laid out a couple weeks back over the gigabit ethernet on my Windows Server machine in the other room. Music detection was quite fast and I appreciated that the program allows me to watch the process happen in realtime, remaining responsive through the whole process.

In use, selecting the audio output was straight forward. For example, on my system upon install, it recognized my TEAC UD-501 USB DAC right away with options for WASAPI and ASIO drivers:

I went ahead and named the TEAC, clicking on "Enable" to allow me to choose the output options I'll be using (these are the "Zones" selectable in the Android/Apple controller app). As usual, I prefer ASIO when possible with my USB DACs. Notice the recognition of AirPlay devices as well over the network including a cheap Kodi TV box running LibreElec. I was in fact quite impressed with the quality of the sound from my Yamaha RX-V781 over AirPlay:

Notice that the cover art gets transmitted across to the AirPlay receiver on playback. One nice thing about Roon is that you can easily see whether the audio data is being converted along the way:

As you can see, the 24/96 original "Source" audio in this example is downsampled to 44.1kHz and dithered down to 16-bits (according to the description when you press on the green button beside "Truncate", there is dithering applied) to the Yamaha.

The big draw for Roon of course is the highly interconnected metadata informed interface. It is indeed fun using Roon; and highly educational with fingertip access to artist bios:

Artistic influences, similarities, and historical context:

One could also click on genres and explore bands and albums in the music collection:

The Discover feature is also great... Don't know what to listen to? Click on this and it'll pull up some interesting albums, genres, artists you might want to check out from the music library:

Also, it's very nice to have song lyrics at the click of a button (the little microphone icon at the bottom):

If you're a DSD music collector, Roon does support .dff and .dst files. However beware that it did not pick up on my DST-compressed DSD64 .dff files. No problem with (uncompressed) DSD128 material I had.

I was able to try multizone simultaneous playback across AirPlay, to a Squeezebox device, and USB local playback all at the same time without issue. So far, so good. Now, let's spend some time evaluating the sound quality.

II. Measurements:

You might be wondering if using another streaming system like Roon resulted in any change in sound quality. As usual there are folks wondering if the sound quality is any good. Here's some data using the RightMark software. The results are based on this set-up:

Intel NUC 6i5SYH (Roon Core, ASIO playback) --> 6' shielded USB cable --> TEAC UD-501 DAC --> 6' RCA cable --> Focusrite Forte ADC --> shielded USB --> Windows 10 measurement laptop

All the cables are generic good quality cables with shielding.

16/44:

What we have here are the RightMark results through the TEAC UD-501 DAC from Roon and foobar both through the NUC machine connected by USB using ASIO. On the right you see the results from a Raspberry Pi 3 connected by USB to the same DAC, streaming using piCorePlayer from my Logitech Music Server running on Windows Server 2016 in the other room.

Here are the composite graphs:

As you can see, these measurements are no different across the systems. At least with 16-bits, we're essentially looking at confirmed bit-perfect output.

24/96:
In the same fashion, let us have a look at high-resolution playback with Roon compared to foobar and the Pi 3 through LMS:

Again, the results demonstrate what we should see from expected bit-perfect output from each of the playback systems. And the graphs...

I trust the results are completely unsurprising. No evidence of sonic anomaly no matter what system is used.

I'm not going to bother with showing you the 24/192 results - they are again the same; no difference between Roon and the other playback conditions. Some might then start asking about jitter with the different solutions:

16-bit J-Test:

24-bit J-Test:

As above, the Raspberry Pi 3 was streaming from Logitech Media Server using piCorePlayer. Apologies for the Pi 3 screen grab being slightly smaller in size; these measurements were done about a month apart.

In any event, the J-test results do not demonstrate any significant jitter issue in the system. In the 16-bit test, we can easily see the jitter modulation pattern showing that the DAC is capable of performing >16-bit resolution with very low noise floor. No jitter sidebands in the 24-bit signal with only minimal "tenting" of the base of the 12kHz primary signal again signifies very low jitter. As usual, asynchronous USB is robust in the time domain despite different hardware connected to the TEAC UD-501 (Intel NUC with i5 processor, and ARM-based Pi 3), as well as different software (foobar, Roon, and piCorePlayer). All of this is not unexpected and corroborates with previous testing like here and opinions expressed here.

III. Conclusions:

On the whole, I must say that generally I liked what Roon does. It provides a nice interface that allows the aggregation of essentially all the audio devices I have here in the home. No problems at all sending music to the DAC attached to the NUC, good playback to Android/iOS devices even. Squeezebox devices can be incorporated "into the fold" when my Windows Server computer's instance of LMS is disabled and the Squeezebox device is connected to the Roon "foo" server. Note that display features on the Squeezebox streamer are disabled when linked to the Roon "Core" - no UV meter, no track titles, no volume level display. Here's my old SB Boom connected to the Roon Core playing some music, notice the VFD screen just shows "roon":

Both the Android and iPad/Phone "Roon Remote" apps ran smoothly and stably. I had no problems with gapless playback of live albums through the NUC and even through the Android tablet device I tried it on. Although the apps are functionally equivalent, I did slightly prefer the Apple iPad Air 2 installation for being a bit more responsive and it was able to show way more than the 20-album limit I saw on the Android devices (Samsung Note 5, Nexus 7, and Vizio's tablet that came with my TV) when reviewing the "Recently Added" list.

Roon's main benefit of course is an interface into the rich metadata provided by the service for each album and easy access to recommendations when exploring music (fantastic Browse --> Discover feature). I also thought the "Focus" feature was a really nice idea, allowing you to review your browsing habits and identifying the most popular or favourite tunes over time. All this power would certainly be a boon to Tidal subscribers with access to streamed music from the huge library of 30M songs.

As you can see from the objective measurements, there's no reason to believe Roon "sounds" any different from any other bit-perfect playback software. Likewise, I have yet to find software that actually changes the jitter test results when using an external asynchronous DAC. (Despite finding ridiculous reviews like this in The Absolute Sound talking about fantastic abilities to hear all kinds of differences! More like The Absolute Nonsense IMO...)

Issues & things I wish it did (remember, I'm talking about version 1.2):
1. Sometimes when I minimize the Roon Core window in a Remote Desktop Connection, the window goes blank and the program seems to hang, requiring the program be force closed and restarted. This seemed to be a problem when I was running it on my Windows Server 2012 R2 machine for a bit but hasn't been an issue on Windows 10 or when testing on Server 2016 although I admittedly did not test as thoroughly.

2. Multiple masterings not being differentiated or displayed. On a recognized album on my own server, it appears the Roon "standard" tagging gets applied in the software (thankfully it does not touch my own customized tags). On some albums, it recognizes the presence of other versions and allows me to choose the "primary" version but this is not consistent and not all variations seem to be picked up and collated. Here's Dark Side of the Moon, but only 2 of 4 versions seem to be picked up (original Japanese Black Triangle and the recent 2011 Immersion version missing here and placed under other instances of the album):

I also have a high-res version of Cat Stevens' Tea For The Tillerman which I couldn't locate at all while Roon only recognized the 16/44 rips. Considering the huge number of albums out there, I certainly am still impressed by what Roon was able to identify properly.

3. Similar to number 2 above, sometimes multi-disk sets end up separated instead of being gathered together. For example my 4-CD set of 10cc's Tenology housed in the same directory ended up with CD1 and CD4 separated while CD's 2 and 3 appropriately were behind the same album cover icon. Strange how that worked out.

4. For devices like the Squeezebox Boom above connected via WiFi across two levels in my house, I wish there was some way to set-up a transcode to MP3 (maybe 256kbps) option to keep data rate low for stability and minimal risk of buffer under-runs. This is something LMS is capable of and I believe it's a feature worth implementing. Maybe throwing in an option here to customize for each device?

5. It would be nice to support DST compression for DSD64 material... Since I have a large portion of my DSD albums compressed as DST .dff files, this is unfortunate. I recognize that this will not be a problem for most people especially since SACD/DSD isn't exactly in high demand. However, foobar and JRiver can handle these compressed files so it would be nice for Roon to as well for completeness.

6. Easier access to a file's ID3 custom metadata? As I described previously, I have my own system of directory and file handling as well as tagging convention. Often I will use the "Comment" field to include data like DR values, DSP settings processing done, etc. I looked around and couldn't seem to access this data in Roon, at least not easily.

Admittedly, even though I was impressed with Roon, ultimately I did cancel the subscription after the 2 week trial period pending further consideration. I must admit that I was tempted to register, but the issues around automatic management of multiple masterings noted above in point 2 really is an issue for me since I have many albums of this nature. I assume the RDC issue (item 1) I had might just be my set-up and not a bug with Roon itself since I believe others have not had this issue looking around.

I'm sure many folks must be wondering about the price of Roon. A yearly fee of US$119 is about the same as a one year subscription of Netflix and what this pays for is a license to use the playback/streaming system supporting a single Core server and the right to access metadata information including artwork; no actual music or other media is transferred of course. Here in Canada, with the way currency conversion is going, I'm looking at CAD$160/year which actually is slightly more expensive than a subscription to the highest quality 4K "Ultra" Netflix tier for me! Again, remember that Roon does not provide actual content - just metadata. Furthermore, consider that for us in Canada, Tidal Hi-Fi costs $20/month, Roon is 2/3 the cost which is not insignificant. I know there are some "apples to oranges" comparisons here and I can appreciate that Roon is a smaller company, but I think it does suggest that only more "hard core" music lovers and audiophiles would likely find the service compelling at this price. I wonder what the cost-analysis looked like for the business plan... I would imagine that a lower cost plan, say <US$50/year would entice significantly more folks to sign on. Like I noted above, there's great educational value in this program and it's a shame that the price is likely a bit steep for most music lovers in the context of competing entertainment options.

Anyhow, at this point, I guess I'll sit on it for a bit... Let's see if I miss the Roon features enough to bite the bullet.

Before I cancelled the trial, I did do a couple things including installing the Bridge to my Raspberry Pi 3 to see how it can be done efficiently and even had a quick look at integration with HQPlayer and the benefits of doing this. Stay tuned in the weeks ahead for a look at these related topics.

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As we end this post, I think it's worth reminding folks that if you like the relational GUI interface that Roon provides, there is another piece of software you might be interested in - muso from klarita.net (current version 2.6).

Compared to Roon, muso isn't aiming to be a feature-filled playback ecosystem. It's job is primarily as an alternative front end to your music library with tag management. It has been an option for years for the Squeezebox crowd, and although not as 'professional' or slick as Roon, does provide many of the functions when it comes to opening up one's library for exploration. It's reasonably easy to set-up to play through LMS, there's last.fm integration for album summaries, on-line images, and artist information, related Wikipedia links, lyric search, and ability to show images in the directory like scanned artwork (this last one is good if you have an art folder or other data in the music directory - scans of front and back album sleeves, DR log for example). It's also only €7/year on a single computer or just pay the €20 for unrestricted home use. A big limitation is that this is a Windows program so no Android/Apple apps although I could use something like RD Client on an iPad or Parallels Client on Android tablet to log into the Windows machine; too clunky to use regularly but works. It definitely would be a major improvement in the AV room if a proper app were available. Also, without integration into an online streaming system (Spotify, Tidal), "You might also like" recommendations are not conveniently linked for playback.

I primarily use it on my Windows workstation often while primarily doing other things (like writing this blog!), listening to music in my collection, learning about the album/artist/genre as I go along...

Muso gallery & artist views.

Muso - the cool beta Pivot viewer... My album collection sorted by year of release from 1960 - 11,834 albums (remasters are tagged to release year so this should be quite accurate)! Each bar represents 6 years worth of albums. Decent amount of stuff from the 60-70's, but definite growth of 90's music and big jump since 2000 when I became a more serious "audiophile"... Hmmm, guess I'm not as much into the oldies as I thought! Cool toy to explore one's collection. You can even zoom into the graph to see the album covers.

Ultimately, I think it's great that software like Roon and Muso are going beyond the usual library functions and allowing us to have easy access to the rich information content in our collections and linking them with the worldwide information super highway. I'm sure there will be more of this to come.

I encourage trying the Roon preview for a couple weeks and see if it fits your needs. Note that Roon does take your credit card information when signing up and will automatically start the $119 subscription billing at 2 weeks unless cancelled. They are good enough to warn you 3 days in advance by E-mail though if you wish to cancel.

BTW: As you see in the text above, I have updated my previous Windows Server 2012 R2 to Windows Server 2016 recently for the home server computer which is essentially my NAS device, runs a web server for work, and runs my Logitech Media Server for music in a virtual machine (as documented here). Remember, Windows Server is part of the Longterm Servicing Branch (LTSB) of the Windows OS. It's meant to be implemented in server and business roles, not as the primary workstation or for multimedia playback even though it can do these things quite well. Over time, the GUI follows the "Current Branch" OS which is currently Windows 10. As a result, Server 2016 has moved away from the Windows 8-style UI (a good thing!) when you install the "Desktop Experience". Remember though that the underlying drivers are still the same as in Windows 10.

Before you start hearing audiophiles claim that Server 2016 "sounds better" or even "different" than Windows 10 or Server 2012 R2... Let's just say I hear no difference with my Audioengine D3 USB DAC. Nor should there be. :-)

Have a great week ahead everyone! Hope you're all enjoying the music...