Here are my initial impressions of the Ref.1s + a quick comparison on how they sound compared to the Fitear MH335DW - which I've owned for a few months now (and no other IEMs inbetween).
Mr Gavin recommends a 250-hr burn-in period before the Ref.1 settles down.
First off, I'm not a self-professed audiophile, just a slightly 'more-than-casual' listener who appreciates good quality audio.
With my limited vocabulary, I think the more hardcore folks here will do much better describing the SQ.
Bass
The first thing that hit me was man, that bass...
I've always preferred phones with a warm signature, mainly for its non-fatiguing character and my choice of music (vocal, jazz, electronica).
Deciding on the Ref.1 was no exception.
Having own the Sennheiser IE800s before, I felt that dynamic drivers offered more realistic bass compared to BA drivers.
I quickly became a fan of dynamic drivers ever since, but from my knowledge, dynamic earphones are far and few between on the market.
Although I was very impressed at the 335's ability to render bass, the Ref.1s take it to another level with its dual isobaric drivers (imho, very reminiscent to, and at times surpassing, my LCD 2.2)
As I go through my music library, the bass not just hits harder, it also had more texture - with a 'bounce' that only dynamic drivers can produce.
The best thing is that it does not mess with the other frequencies from my time A/B-ing both on the Herus.
I think once you hear bass on a Ref.1, bass on BA won't sound quite right anymore.
Mids
The mids are something which, to me, shouldn't be overly forward or recessed.
With the Ref.1's, they felt just right and balanced with the rest of the spectrum, perfect.
Treble
The Ref.1s had slightly better treble extension and were more present compared to the 335.
They gave instruments eg. acoustic guitars, a more delicate and exquisite feel with the additional level of detail.
There's also more air and instrument separation resulting in better clarity and a wider soundstage, both made songs more enjoyable.
The thing that left me wanting more -that being a universal- they obviously don't fit like a custom do.
But this is more of me being spoilt by customs over time. However, they are quite easy to get a decent seal.
The surprisingly lightweight units and smaller profile were plusses in my book in terms of ergos and comfort
compared to larger universals like the TG334 and JH Roxannes.
The incredible bass resolution, better treble presence, and wider soundstage - gives the Ref.1s an overall sweeter and livelier presentation.
For others who have tried them and as Anakchan would put it - "toe-tapping",
I'd say the Ref.1s will easily have your "head-nodding" to the music as soon as you put them on.
I was also lucky enough to briefly try out a pair of 1+2's with Silver/Gold cable that Gavin brought, and his personal rig: AK240+balanced Uber+Ref.1
He also points out that the Ref.1 thrives on DSD, which after listening to his setup, is seriously making me very tempted to replicate his combination. Urgh.