Since the R1 is on the bright side, in spite of a staggering amount of bass, I prefer to pair it with a warmer source. Of course, your tastes may differ. As far as driving power, these IEM’s don’t require much. More than some IEMs, but nothing too outrageous. Any DAP will drive them sufficiently.
My TOTL choice for the R1 is theBit’s Opus#2 ($999, Review HERE. It has a touch of warmth, and is by far the most natural, organic DAP I’ve heard. Spacious, holographic, deep and resolving as f**k. It helps with the R1’s brightness problem, while feeding its strengths. Hard not to be wowed to death by this setup.
In terms of tonality, my favorite pairing was the Opus#1S ($399, Review HERE). It’s warmer than the #2, but not as technically impressive. Soundstage is smaller, resolution is lesser, and details aren’t as readily accessible. Yet it tamed that treble and added smoothness across the spectrum, which is ever so welcome. Oh yes, it’s a yummy combo.
The Cayin N5ii ($369, Review HERE) walks that line between bright and warm. It’s severely neutral, with just a hint of warmth. It has a full sound, with strong dynamics, but it’s also wildly resolving, thanks to higher frequencies which aren’t f**king around. And that’s the key to why this pairing isn’t my favorite in the mid-tier. The R1 needs a large helping of added warmth from the source, and Cayin’s new player is too balanced. Now, that’s not to say I don’t actually like this coupling. I do. It sounds amazing. But given a choice, I think the R1 sounds better with less treble. YMMV.
Continuing this trend of Clarity=Bad, the DX200 with AMP4 Module ($899, Review HERE) is my least favorite source for the R1. Which is confusing, because it is my favorite DAP. It’s the most detailed, transparent, and holographic, with the largest soundstage, best layering, and highest resolving. And holy shit, the R1 scales up to some insane extreme of its ideals. But that’s where we meet the R1’s old nemesis: hot treble. What can I say? It sounds awesome. Of course it does. But the R1 really, really, really sounds its best when given a smoother, warmer signal.
The IMR Acoustics R1 impressed the shit out of me. The bass, the clarity, the endless highs… it’s a goddamn showstopper. With the vents open, it sounds all the more spacious and airy, like a good open-back set of cans. I recommend a custom cable, just to avoid the demented antagonism of those stock cords. Other than that, simply be sure you aren’t overly sensitive to bright sounds, and I’d say the R1 is for you. It’s so good you may quit the hobby forever and call it a day.