Post 50 hour burn-in update.
Memory being what it is, I took notes on details that I could go back and objectively track, then compared them to current experience. When not listening, pink noise is running through my R2s at 80% volume using my Asus Xonar STX in High Performance mode.
1. The overall experience remains coherent, and more "fun" than quick, detailed and precise, as might be expected from a massive DD. The R2s prefer a neutral source with some power (LG G8 in aux mode) to a warmer source (Chord Mojo).
2. There was a notable shift in the piezo about halfway through burn-in, where the green tips, my go-to for pop-ish modern recordings, got WAY too hot in the upper treble regions (sibilants, cymbal crashes, etc.). After ~10 more hours of burn-in the issue resolved itself, and I was able to go back to the green tips again, but the treble had changed from my previous notes- it was no longer crystal clear and cutting, but had gained more weight and body. These are still not reference-neutral in the treble, but are solid and tangible in a way that balances and connects well with the rest of the signature.
3. I am NOT a basshead by any means. I prefer DF-neutral with slightly elevated clean and impactful bass, texture and details in the mids and smooth but precise treble that extends through the audible harmonic ranges and beyond. New, the R2s tilted hot in the subbass, and the slam and body continued into the midbass with quite a bit of weight and warmth- even to the point of overwhelming and overtaking the midrange (balance, not bleed) and feeling distorted (even though it wasn't, the bass felt that way), even slightly over-warm and bloated. The purple filters helped, but lost the impact of the red and black filters. After ~20 hours of burn-in I switched over to the purple flters full time for most things, because they were just so much cleaner than the red filters, although lacking visceral impact.
I switched back to the red filters today and noticed more visceral slam, just as they had been earlier, but midbass clarity and balance are markedly better, with bass guitars, bass violins and cellos the biggest benefactors. The purple is now bass how I generally prefer it- slightly elevated, clean and visceral- and red is clean bass but bigger and deeper, a "fun" take on my regular preference.
Current preference:
Red filter green tip for pop and modern recordings
purple filter blue tip for live recordings, traditional Americana
purple filter gold tip for classical orchestral, jazz
3 things real quick.
1. These are, as Bob describes them, IEMs for enjoying music, not for analyzing music. I'm a degreed musician with over 30 years of live performance and leadership experience. It's incredibly difficult for me to enjoy music without analyzing it. With the R2, I am enjoying music for its sake in a way I haven't experienced for years, maybe a decade.
2. If this were a typical IEM, I'd likely be satisfied with the purple filter blue tip combo for everything, but thanks to Bob's initiative, we're able to tune these in small ways until they are closer to ideal for our preferences. The filter and tip combo can be challenging at first, but it's more robust, and I think longer lasting than some of the micro switch solutions that are sweeping the industry.
3. I'm not a big burn-in believer. Out of all the IEMs, headphones, amps and speakers I've had through here, these are by far the best example of FR, even SQ changing with burn-in. The overall experience is just cleaner and more cohesive after 50 hours, as suggested by Bob, and I can't wait to see what 100 hours brings. At certain points in the process SQ changed for the worse. When you reach those points, adjust for the short term and keep going; it will get better. It will be worth it.
