This is a new IEM about to be released. Stay tuned for details. @netforce: feel free to chime in on details. The Apollo is a hybrid DD + 2 BA IEM. I don't know if the world has changed much, but typically hybrid IEMs that use two or more different types of drivers have always had integration issues. Note even Sony with their flagship IEM could pull this off, and I quote @Kunlun: That said, play a cello concerto (one instrument, full range) and listen to the emperor have no clothes as Yo-Yo Ma ends up sounding like he is playing a trio of slightly different instruments in a test that a much cheaper single driver iem passes easily. I think I'll leave it at that. Where I will start is that I do expect the band members, or the drivers in this case, to play as a band and not as individuals. I don't expect the timbres of the different drivers to sound the same, as this is impossible, even with multi-way speakers. However, I do expect that the frequency ranges where the drivers overlap and hand the signal off, to sound cohesive and as seamless as possible. This is just one of my pet peeves, whether it comes to multi-driver speakers or IEMs (sometimes I wonder if folks outside of SBAF notice such things concerning overall cohesiveness.) The good news is that California Audio Technology or CAT, manages to pull this off with their Apollo hybrid IEM. The driver integration is on-par with another hybrid IEM that pulls it off decently, the Campfire Audio Solaris. That's two IEMs in my book (there may very well be more today, but I have not gotten my ears on them yet). One thing I wanted to get out of the way is that unlike most other IEMs, the wires hang down. These IEMs are not intended to be used like most other IEMs were the wire exits up top, and around the back of the ear, with a shaped tube or guide. I did try it the other way, but the design of the shell prevents this from fitting to the concha properly. For this market, more upscale IEMs I would assume, the consumer fitment with the wirings dangling down, feels a bit off. As we can see above, CAT has taken an conservative approach with the Apollo to fitment by having the nozzle exit from a smaller cylindrical structure on top of the body instead of directly from the body. This will probably guarantee fit for more people, but it also leads to a somewhat of a Lt. Uhura earpiece effect where the body sticks quite a bit from the ears. As such, and with the nozzle not being particularly long, a deep insertion is not possible. (As an aside, I don't think a deep insertion is optimal for this IEM). The best way I got these to fit is with larger size tips and a shallow insertion. I opted for the fancy Acoustune Azla Sedna Earfit tips (in Acoustune case) which @rhythmdevils sent me. The silicone is a bit stiffer and less prone to deformation than most other tips. This allows the use of a larger tip that fills the outside of my concha that is secure and without leaks. I keep the fit somewhat loose with these and they are good helping the IEM stay put.