For the S-EM6, there is a thread going on : http://www.head-fi.org/t/681504/earsonics-s-em6-six-driver-universal-iem
But since I have got them for a week and gave them 50 hours before returning them, and now own SE846 I can try to give you an opinion (I am by no way an experienced audophile but I have been diving deeper and deeper over the last 5 years).
There are some obvious differences :
- The S-EM6 is the universal version of the custom EM6 IEM, the first taunting 6 BA drivers (in a 3 way configuration) while it's said to be tuned differently my feeling was that they were still tuned for stage more than audiophile approach
- The SE846 are the result of several years of R&D, redesigning from the ground up, with custom BA drivers and the patent pending true subwoofer thingy that sets those in a category of their own
The main difference I see between the two :
- SE846 is easier to drive you can use them with a good DAP / S-EM6 need a good amp/DAC : Although the S-EM6 has a impedance of 60ohms it has very good sensitivity and driving them loud enough even with a good DAP or smartphone is possible but really without an amp I think you're missing half the equation / the SE846 is very easy to drive with a 9ohm impedance and high sensitivity. It's easier to get a very good SQ even with a good DAP (no external amp / DAC). That's something to consider in the choice as well.
- Sound signature layered / precise versus holistic / fun : If you're familiar with the mid centric / laid back house sound of Earsonics you'll recognize the signature overall with a big difference in the bass department with say SM3v2 : the S-EM6 has deep, textured and well extended bass. Mids are lush and detailed. There are layers and layers of sound. Soundstage is wide but most importantly deep. Trebles are detailed as well but very smooth (too much ?). If I had to find a word I'd say S-EM6 are analytical without bright treble. One thing that struck me is that it was a hit or miss for me depending on what kind of music I listened to, I think those are unforgiving on mastering sound can just... not be up to par and then be fantastic but I never had any emotion with those. Why I returned them.
On the other hand the SE846 with neutral filter has way more sparkle in the treble (I didn't expect this, from all the reviews and forum post). The bass is really something different as you get that unique sub bass. It's so visceral. The vocals are more forwards and the mids are detailed and "rounded" but not as lush as S-EM6. I find the sound is less "layered" in the sense that it's not a millefeuille of sounds : the SE846 sound more "coherent", as in holistic. The are more musical to me. I don't mean that the SE846 has less detail (actually it has more IMHO, especially instruments are rendered better, cymbals, guitars...). Also they are pretty much all rounders in terms of genre they can handle, maybe classical is less of a done deal I like IE800 better there, or Final Audio products.
It's a short summary of my subjective appreciation for both.
Note that the S-EM6 packaging reflect the main market for Earsonics, which is pros. Those are man made in France. The bare minimum is included in the packaging, the focus in on the product itself, as opposed to the amazing packaging of the SE846 which is just the best I have seen (wow).
Edited by davidmolliere - 1/1/14 at 10:03am
One big factor to consider is also that the SE846 has filters that allow to customize the sound to warmer or brigther sound... this is a definite plus, for example I like the warm filter better so far.