After researching for almost a whole year, I finally decided on the 1964 Ears / 64 Audio V8 CIEM. The V8 has (4) armatures for the low, (2) armatures for the mids, and (2) armatures for the highs. The sound from the drivers is routed through the monitors via (3) sound ports in order to keep the different frequencies separated. Everything is tied together through a 3-way passive crossover.
I purchased the V8s during a busy time for the company; they were in the process of changing locations and combined with some difficulties with my ear shape, the wait time for these was around 8 weeks. They were definitely well worth the wait! The fit, finish, and sound quality is all amazing! They isolate you and transport you right in the middle of whatever you are listening to. The fist time I put them in my ears and played something through them, I could not stop smiling. Even with my high-end full-size over-the-ear headphones, I have never felt this connected with my music, movies, or games.
My opinion of the V8s sound is:
Soundstage: quite roomy for a CIEM, and you can easily place the instruments.
Lows: the best part of the V8 in my opinion. The (4) dedicated drivers can really handle the low frequencies and reach down into the sub-bass quite wonderfully. The bass is bigger, deeper, and tighter than my full-size planar magnetic headphones. All this, while still being totally controlled and tight. The best way to describe it is to say if it was in the recording, the V8 brings it out.
Mids: mids are definitely nice. Some people worry that with the extra low drivers, the mids and highs are neglected or drowned out. That is not the case at all and the mids are actually quite warm and nice.
Treble: my ears are highly sensitive to higher frequencies and a lot of headphones hurt my ears when songs feature 'hot' treble. This was another reason I sought out the V8s. Nothing is lost in the highs, but they are just warm and more mellow or smoothed out.
Impedance: being only 18ohms, which is pretty standard for most other (8) armature CIEMs, they are ridiculously easy to drive. On my Macbook Pro, the lowest volume notch it too loud, so I go into Settings and turn it down to barely on. Same with my iPhone, and iPod devices. I own a ALO PanAm tube headphone amp, but I have not tried it out with the V8s. There is a switch on the amp for high/low impedance phones and I have heard that CIEMs work quite well with it. Other V8 owners have stated that even though not necessary in the least, running them through an amp can bring out even more from them.
Tech Specs of the V8 CIEM:
Impedance: 18 Ohms at 1kHz
Sensitivity: 117dB SPL @ 1mW
Freq. Response: 10Hz – 20 kHz
Noise Isolation: -26dB
