I'll try to keep it short. Played with Roon and MPD on three different setups:
Setup and gear:
1) Headphones (BDP-1 -> Roon/MPD -> Dangerous Music Source (w/LPS) -> Senn HD 800)
2) Nearfield monitors (BDP-1 -> Roon/MPD -> Dangerous Music Source -> Amphion Amp100 -> Amphion One15 (w/Amphion cabling))
- Room size: 11 feet x 14 feet x 8 feet with monitors in a ~1.0m triangle
3) Midfield monitors (Macbook Pro USB out via Roon -> Emotiva DC-1 -> Mackie HR 824 Mk1)
- For this I couldn't take my BDP-1 as there was no ethernet options there, but proved valuable nonetheless as Roon's signature held up even without the BDP-1
- Room size: 15 feet x 60 feet x 8 feet with monitors in a 10 feet triangle
Notes:
- I had absolutely zero problems with Roon playback or dropout. So I'm very sure I got the best out of Roon.
- Sound signature of the equipment: All the DACs are on the neutral side. HD 800 and the Amphion rigs are being used in top mixing and mastering suites and should be considered neutral. Amphions as vibey ATCs. Pretty much the same resolution, but even improved imaging.
- The Mackies are more pleasing to listen to. More forgiving with bass going down to 30 Hz in my bigger room.
Objective assessment:
MPD in comparison to Roon:
- More 3D sounding
- Smoother sounding, especially noticeable in vocals
- Perhaps a touch on the warmer side, or you can say Roon is colder depending on your taste (I vote for MPD as warm and Roon as neutral)
- I didn't pay that much attention to bass (which is a good indicator in itself!), but both seemed spot on. No problem with either.
Roon in comparison to MPD:
- Tendency to be more 2D sounding, although on good recordings, Roon has just as much depth as MPD (Diana Panton - If the Moon Turns Green album was a good litmus test for me).
- Noticeably better imaging than MPD. On headphones, I might prefer MPD at times, but on speakers Roon always imaged better. Even on tracks where I know there are 5 degree pans, it was very easy to pick up on Roon. Studying imaging on Roon was a passive job, no energy required at all. With MPD, it seemed a bit sloppy.
- On the midfield setup, Roon had the strongest centerstage performance. The phantom image was dead on there.
Somewhat subjective and objective:
+++ Roon possesses more grittyness and rawness in the vocals and better substance of the tracks: I mean this in a very good way. I always had a feeling in the back of my mind that MPD was over smoothening things over, and it was made conscious after Roon.
- When I went to MPD after few days of being exclusive to Roon, it was a nice change at first to have a 3Dish soundstage, but felt suffocating after awhile because the imaging wasn't at tight. The Amphions really helped with that, even more so than the HD 800.
- The lack of imaging coupled with over smoothening of vocals just made me uneasy.
- This is the same reason I sold my LCD-3 Classic and actually preferred both LCD-2.2 Classic and HD 800 over it. The LCD-3 were smoothening the vocals despite being 3D and having high resolution. The lack of texture, grit, and rawness in vocals just made me feel uneasy. Even rappers sounded like jazz singers!
- I would associate MPD with LCD-3 in this case.
- If the vocals are smooth, then they should come out as smooth. If there's coarseness present, then I want to hear that as well.
- Just in case somebody asks if this correlates with Distortion, or my preference for supposed distortion, NO it's not. It's two different things and I am very aware on my nearfield and headphone systems.
What I'd suggest to others in what to look for: pick somebody with the smoothest voice like Diana Panton and grab another track (rap or R&B with a rugged voice). Pay special attention to how the texture is resolved on both songs on MPD vs. Roon. I'd be surprised if it wasn't noticeable after awhile. Sure, you might like one more than the other, but at the least you should be able to notice that it DOES EXIST.
My recommendation:
For headphones: MPD might get the nod because they benefit and need more from the 3D nature of MPD
For speakers: Once you get used to the somewhat flatter presentation of Roon, you will reap the benefits of the vocals on Roon. I also noted my tendency to lean in more when listening to Roon and sitting back when listening to MPD. MPD was very much in my face, whereas Roon was a bit back, but once you put some effort, the vocals were there for easy cherry picking in the soundstage.
I think I am missing one or two other things I wanted to comment about, but I'm drawing a blank currently.