One major advantage of customs over mentioned cans (HD800s, Stax) is isolation.  I live in a rather quiet apartment, but I'll still hear the occasional footsteps, car go by, or door closing.  Acrylic customs don't seem that much better than Etys for isolation, but are still far better than those cans in noise blocking.

I can see why people are hesitant to get $1000 customs but not $1500-2000 cans.  You can't truly demo customs in my opinion.  For me, the Comply foam tips that they often use on demos completely change the sound.  I did not get to listen to the UE demos at the last meet, which I think had the silicon TF10 tips.  I can see those being a bit closer to the 'real deal'.  I think you can get maybe 75% of what a fit-to-your-ear custom can deliver, while you might get 95% of what a can could deliver at a mini-meet or from a loaner (not including component matching in either case).  And of course you could buy used HD800s, LCDs, or Stax, not like them, and sell them for minimal (if any) loss.

For me, I like to switch between IEMs and cans because sometimes I just don't feel like sticking something in my ear, and other times I don't feel like having pads on my face.

Is it accurate to say that up until recently (UERM), customs have primarily been for stage monitor use where they needed to be tuned to compensate for ambient noise, body movement, and possible hearing loss?  So most of these, while sounding  'fun' and good for perhaps a commute, might not be as neutral as some would like.

So it could be a chicken/egg thing:  Audiophiles aren't interested and therefore are not buying these; so customs manufacturers won't do the R&D or even tailor a model for such a small group of people.  Maybe success of the RMs will expand this market.

I've actually just started getting back into cans and I can't help but to think that there is something different to their sound, all other things being equal (tonal balance, dynamics, detail).  Maybe it's in my head (no pun), but I would imagine the effects of the outer ear on sound might have something to do with it.

Is it accurate to say that up until recently (UERM), customs have primarily been for stage monitor use where they needed to be tuned to compensate for ambient noise, body movement, and possible hearing loss?  So most of these, while sounding  'fun' and good for perhaps a commute, might not be as neutral as some would like.

Yes, completely accurate.  The ES5 is a stage monitor, non fatiguing highs, bit more bass presence, solid mids, vinyl tips all for reasons you mentioned. Still neutral enough to enjoy in quiet listening and with a flat source that doesn't accentuate the lowend or roll off the top.


UERM is a pure studio monitor for shredding recordings. Of course more neutral but not 100% to my neutral/natural preference. 


My ideal IEM is right in the middle of both based on the majority of the music I listen to.  That might be a Spiral Ear 5.  Maybe.  I have Joe's coming in to see if I can cram into my ears.   

Max, since you've been wondering, forgot to mention the HD800 and HE60 share a lot in common if that gives you any sort of inkling.  They sound very similar, not idenical and even share many measurements.  You can almost make out a Sennheiser targeted reference between the two.  OT, done.

Ok, cool.  Sounds like you know exactly what you are getting.