Hey That is interesting. I own an older cheap pair of JBL IEMs that I use to use for running now I have 2 pairs of JayBirds and my wife has Powerbeats, neither of which are on the list, so using the old JBLs I picked the cheapest JBL headphones they had.
The set I have definitely have a hollowness to the sound and it took a few examples to figure out what I was hearing, plus I had no idea what songs they were playing, so I struck up my home system (Naim Uniti Star and Dynaudio Focus 260s) listened to how they sound in person then listened to the Emit 30s to compare, even tho they’re 2 lines lower, they have some similar traits (yes different rooms I know) but that gives me some amount of a baseline to compare how my IEMs influenced the sound. This is still flawed, for many reasons.... but humor me.
At “equal volume” using the Emit 30 as the control speaker for which to come back to, speakers in the comparison were similarly priced, 2-way designs. MA Silver 200, SVS prime tower and Elac uf5. I used these speakers because I’m familiar with their sound, except the Elac, which was new to me. However I have heard Pioneer Elite and TAD speakers. What I found was that the differences in pitch especially top-end was noticeable the most but low-end weight was similar. I could tell the Emit 30 had a fuller sound and slightly reduced top-end energy vs the MAs and SVS, although the SVS had a fuller sound then the MAs. The Elacs seemed slightly subdued in the highs and mids, but bass was decent. In person my opinion of the SVS was that they’re a foreword sounding speaker with good but slightly boomy bass. The MAs (RS6) was a bright speaker with good bass, the (RX6 & Silver 6) was a warmer more balanced speaker with quick punchy bass, but didn’t dig exceptionally deep. The Dynaudio DM3/7 which I have heard many many times because my closest friend has them and were replaced by the Emit 30, was highlighted with strong deep bass like SVS but tighter sounding, smooth top-end, however a good but slight recession in the upper midrange. I can’t say if the Emit 30s have the same character or not for sure, and the IEM demo doesn’t do anything to show it or not.
Switching to bookshelf speakers, the Emit 10, Kef LS50 and Revel M105 were in my list. I own Dynaudio DM2/6s so I have the Emit 10s cousins, I had 2 long auditions with the LS50s and spent time with the Revel F206s. The LS50 sounded like the LS50, rolled highs and lacking bass, but lacked the rich textured mids, the Emit 10 and the M105 sounded very similar with maybe a touch more treble energy going to the M105s.
Knowing what Dynaudio speakers sound like, I can say that the tonality of the Emit 30s and Emit 10 was missing a little. While some difference could be found between the different speakers, the absolute tonality, inner detail, soundstage width and depth is only showing up as much as the IEMs would allow and I felt that they lacked quite a bit. This isn’t to me, a way to replace auditioning speakers, there’s too much personality I felt was missing from the demo to actually say that’s what this or that speaker sounds like. Maybe if you have their reference headphones you’d get a true experience. Probably worth the $25 trial. YMMV. Steve